原文地址：笛卡尔“我思故我在”作者：乐其可知也
Cogito ergo sum
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Cogito ergo sum (French: "Je pense donc je suis"; English: "I
think, therefore I am") is a philosophical Latin statement proposed
by René Descartes. The simple meaning of the phrase is that someone
wondering whether or not he or she exists is, in and of itself,
proof that something, an "I", exists to do the thinking. However,
this "I" is not the more or less permanent person we call "I". It
may be that the something that thinks is purely momentary, and not
the same as the something which has a different thought the next
moment.[1]
The phrase became a fundamental element of Western philosophy,
as it was perceived to form a foundation for all knowledge. While
other knowledge could be a figment of imagination, deception or
mistake, the very act of doubting one's own existence serves to
some people as proof of the reality of one's own existence, or at
least that of one's thought.
The statement is sometimes given as Dubito, ergo cogito, ergo
sum (English: "I doubt, therefore I think, therefore I am").[2] A
common mistake is that people take the statement as proof that
they, as a human person, exist. However, it is a severely limited
conclusion that does nothing to prove that one's own body exists,
let alone anything else that is perceived in the physical universe.
It only proves that one's mind exists (that part of an individual
that observes oneself doing the doubting). It does not rule out
other possibilities, such as waking up to find oneself to be a
butterfly who had dreamed of having lived a human life.
Descartes's original statement was "Je pense donc je suis,"
from his Discourse on Method (1637). He wrote it in French, not in
Latin and thereby reached a wider audience in his country than that
of scholars.[citation needed] He uses the Latin "Cogito ergo sum"
in the later Principles of Philosophy (1644), Part 1, article 7:
"Ac proinde hæc cognitio, ego cogito, ergo sum, est omnium prima
& certissima, quæ cuilibet ordine philosophanti
occurrat." (English: "This proposition, I think, therefore I am, is
the first and the most certain which presents itself to whoever
conducts his thoughts in order."). At that time, the argument had
become popularly known in the English speaking world as 'the
"Cogito Ergo Sum" argument,' which is usually shortened to "Cogito"
when referring to the principle virtually everywhere else.
Introduction
The phrase Cogito ergo sum is not used in Descartes'
Meditations on First Philosophy but the term "the cogito" is (often
confusingly) used to refer to an argument from it. In the
Meditations, Descartes phrases the conclusion of the argument as
"that the proposition, I am, I exist, is necessarily true whenever
it is put forward by me or conceived in my mind." (Meditation
II.)
At the beginning of the second meditation, having reached what
he considers to be the ultimate level of doubt — his argument from
the existence of a deceiving god — Descartes examines his beliefs
to see if any have survived the doubt. In his belief in his own
existence, he finds that it is impossible to doubt that he exists.
Even if there were a deceiving god (or an evil demon), one's belief
in their own existence would be secure, for there is no way one
could be deceived unless one existed in order to be deceived.
But I have convinced myself that there is absolutely nothing
in the world, no sky, no earth, no minds, no bodies. Does it now
follow that I, too, do not exist? No. If I convinced myself of
something [or thought anything at all], then I certainly existed.
But there is a deceiver of supreme power and cunning who
deliberately and constantly deceives me. In that case, I, too,
undoubtedly exist, if he deceives me; and let him deceive me as
much as he can, he will never bring it about that I am nothing, so
long as I think that I am something. So, after considering
everything very thoroughly, I must finally conclude that the
proposition, I am, I exist, is necessarily true whenever it is put
forward by me or conceived in my mind. (AT VII 25; CSM II
16–17)
There are three important notes to keep in mind here. First,
he claims only the certainty of his own existence from the
first-person point of view — he has not proved the existence of
other minds at this point. This is something that has to be thought
through by each of us for ourselves, as we follow the course of the
meditations. Second, he does not say that his existence is
necessary; he says that if he thinks, then necessarily he exists
(see the instantiation principle). Third, this proposition "I am, I
exist" is held true not based on a deduction (as mentioned above)
or on empirical induction but on the clarity and self-evidence of
the proposition.
Descartes does not use this first certainty, the cogito, as a
foundation upon which to build further knowledge; rather, it is the
firm ground upon which he can stand as he works to restore his
beliefs. As he puts it:
Archimedes used to demand just one firm and immovable point in
order to shift the entire earth; so I too can hope for great things
if I manage to find just one thing, however slight, that is certain
and unshakable. (AT VII 24; CSM II 16)
According to many of Descartes' specialists, including Étienne
Gilson, the goal of Descartes in establishing this first truth is
to demonstrate the capacity of his criterion — the immediate
clarity and distinctiveness of self-evident propositions — to
establish true and justified propositions despite having adopted a
method of generalized doubt. As a consequence of this
demonstration, Descartes considers science and mathematics to be
justified to the extent that their proposals are established on a
similarly immediate clarity, distinctiveness, and self-evidence
that presents itself to the mind. The originality of Descartes'
thinking, therefore, is not so much in expressing the cogito — a
feat accomplished by other predecessors, as we shall see — but on
using the cogito as demonstrating the most fundamental
epistemological principle, that science and mathematics are
justified by relying on clarity, distinctiveness, and
self-evidence.
Baruch Spinoza in "Principia philosophiae cartesianae" at its
Prolegomenon identified "cogito ergo sum" the "ego sum cogitans" (I
am a thinking being) as the thinking substance with his ontological
interpretation. It can also be considered that Cogito ergo sum is
needed before any living being can go further in life".[3]
Predecessors
Although the idea expressed in Cogito ergo sum is widely
attributed to Descartes, he was not the first to mention it. Plato
spoke about the "knowledge of knowledge" (Greek νόησις νοήσεως -
nóesis noéseos) and Aristotle explains the idea in full
length:
But if life itself is good and pleasant (...) and if one who
sees is conscious that he sees, one who hears that he hears, one
who walks that he walks and similarly for all the other human
activities there is a faculty that is conscious of their exercise,
so that whenever we perceive, we are conscious that we perceive,
and whenever we think, we are conscious that we think, and to be
conscious that we are perceiving or thinking is to be conscious
that we exist... (Nicomachean Ethics, 1170a25 ff.)
Augustine of Hippo in De Civitate Dei writes Si […] fallor,
sum ("If I am mistaken, I am") (book XI, 26), and also anticipates
modern refutations of the concept. Furthermore, in the Enchiridion
Augustine attempts to refute skepticism by stating, "[B]y not
positively affirming that they are alive, the skeptics ward off the
appearance of error in themselves, yet they do make errors simply
by showing themselves alive; one cannot err who is not alive. That
we live is therefore not only true, but it is altogether certain as
well" (Chapter 7 section 20). Another predecessor was Avicenna's
"Floating Man" thought experiment on human self-awareness and
self-consciousness.[4]
Criticisms
There have been a number of criticisms of the argument. One
concerns the nature of the step from "I am thinking" to "I exist."
The contention is that this is a syllogistic inference, for it
appears to require the extra premise: "Whatever has the property of
thinking, exists", a premise Descartes did not justify. In fact, he
conceded that there would indeed be an extra premise needed, but
denied that the cogito is a syllogism (see below).
To argue that the cogito is not a syllogism, one may call it
self-evident that "Whatever has the property of thinking, exists".
In plain English, it seems incoherent to actually doubt that one
exists and is doubting. Strict skeptics maintain that only the
property of 'thinking' is indubitably a property of the meditator
(presumably, they imagine it possible that a thing thinks but does
not exist). This counter-criticism is similar to the ideas of
Jaakko Hintikka, who offers a non-syllogistic interpretation of
Cogito Ergo Sum. He claimed that one simply cannot doubt the
proposition "I exist". To be mistaken about the proposition would
mean something impossible: I do not exist, but I am still
wrong.
Perhaps a more relevant contention is whether the "I" to which
Descartes refers is justified. In Descartes, The Project of Pure
Enquiry, Bernard Williams provides a history and full evaluation of
this issue. Apparently, the first scholar who raised the problem
was Pierre Gassendi. He points out that recognition that one has a
set of thoughts does not imply that one is a particular thinker or
another. Were we to move from the observation that there is
thinking occurring to the attribution of this thinking to a
particular agent, we would simply assume what we set out to prove,
namely, that there exists a particular person endowed with the
capacity for thought . In other words, the only claim that is
indubitable here is the agent-independent claim that there is
cognitive activity present[5] The objection, as presented by Georg
Lichtenberg, is that rather than supposing an entity that is
thinking, Descartes should have said: "thinking is occurring." That
is, whatever the force of the cogito, Descartes draws too much from
it; the existence of a thinking thing, the reference of the "I," is
more than the cogito can justify. Friedrich Nietzsche criticized
the phrase in that it presupposes that there is an "I", that there
is such an activity as "thinking", and that "I" know what
"thinking" is. He suggested a more appropriate phrase would be "it
thinks." In other words the "I" in "I think" could be similar to
the "It" in "It is raining." David Hume claims that the
philosophers who argue for a self that can be found using reason
are confusing "similarity" with "identity". This means that the
similarity of our thoughts and the continuity of them in this
similarity do not mean that we can identify ourselves as a self but
that our thoughts are similar.[citation needed]
Williams' argument in detail
In addition to the preceding two arguments against the cogito,
other arguments have been advanced by Bernard Williams. He claims,
for example, that what we are dealing with when we talk of thought,
or when we say "I am thinking," is something conceivable from a
third-person perspective; namely objective "thought-events" in the
former case, and an objective thinker in the latter.
Williams provides a meticulous and exhaustive examination of
this objection. He argues, first, that it is impossible to make
sense of "there is thinking" without relativizing it to something.
However, this something cannot be Cartesian egos, because it is
impossible to differentiate objectively between things just on the
basis of the pure content of consciousness.
The obvious problem is that, through introspection, or our
experience of consciousness, we have no way of moving to conclude
the existence of any third-personal fact, to conceive of which
would require something above and beyond just the purely subjective
contents of the mind.
Søren Kierkegaard's critique
The Danish philosopher Søren Kierkegaard provided a critical
response to the cogito.[6] Kierkegaard argues that the cogito
already pre-supposes the existence of "I", and therefore concluding
with existence is logically trivial. Kierkegaard's argument can be
made clearer if one extracts the premise "I think" into two further
premises:
"x" thinks
I am that "x"
Therefore I think
Therefore I am
Where "x" is used as a placeholder in order to disambiguate
the "I" from the thinking thing.[7]
Here, the cogito has already assumed the "I"'s existence as
that which thinks. For Kierkegaard, Descartes is merely "developing
the content of a concept", namely that the "I", which already
exists, thinks.[8]
Kierkegaard argues that the value of the cogito is not its
logical argument, but its psychological appeal: a thought must have
something that exists to think the thought. It is psychologically
difficult to think "I do not exist". But as Kierkegaard argues, the
proper logical flow of argument is that existence is already
assumed or pre-supposed in order for thinking to occur, not that
existence is concluded from that thinking.[9]
Notes
^ Baird, Forrest E.; Walter Kaufmann (2008). From Plato to
Derrida. Upper Saddle River, New Jersey: Pearson Prentice Hall.
ISBN 0-13-158591-6.
^ It appears in an anonymous introduction, from 1765, signed
by "Thomas," which was included in the Descartes edition by Victor
Cousin and is accessible, together with Descartes' works at the
Gutenberg Project.[1]
^ Vesey, Nicholas (2011). Developing Consciousness. United
Kingdom: O-Books. p. 16. ISBN 978-1-84694-461-1.
^ Seyyed Hossein Nasr and Oliver Leaman (1996), History of
Islamic Philosophy, p. 315, Routledge, ISBN 0-415-13159-6.
^ Saul Fisher. "Pierre Gassendi". Retrieved 2010-11-02. from
Stanford Encyclopedia of Philosophy
^ Kierkegaard, Søren. Philosophical Fragments. Trans. Hong,
Princeton, 1985. p. 38-42.
^ Schönbaumsfeld, Genia. A Confusion of the Spheres. Oxford,
2007. p.168-170.
^ Kierkegaard, Søren. Philosophical Fragments. Trans. Hong,
Princeton, 1985. p. 40.
^ Archie, Lee C, "Søren Kierkegaard, God's Existence Cannot Be
Proved". Philosophy of Religion. Lander Philosophy, 2006.
Further reading
W.E. Abraham, "Disentangling the Cogito", Mind 83:329
(1974)
Z. Boufoy-Bastick, Introducing 'Applicable Knowledge' as a
Challenge to the Attainment of Absolute Knowledge , Sophia Journal
of Philosophy, VIII (2005), pp 39–52.
R. Descartes (translated by John Cottingham), Meditations on
First Philosophy, in The Philosophical Writings of Descartes vol.
II (edited Cottingham, Stoothoff, and Murdoch; Cambridge University
Press, 1984) ISBN 0-521-28808-8
G. Hatfield, Routledge Philosophy Guidebook to Descartes and
the Meditations (Routledge, 2003) ISBN 0-415-11192-7
S. Kierkegaard, Concluding Unscientific Postscript (Princeton,
1985) ISBN 978-0-691-02081-5
S. Kierkegaard, Philosophical Fragments (Princeton, 1985) ISBN
978-0-691-02036-5
B. Williams, Descartes, The Project of Pure Enquiry (Penguin,
1978) OCLC 4025089
Baird, Forrest E.; Walter Kaufmann (2008). From Plato to
Derrida. Upper Saddle River, New Jersey: Pearson Prentice Hall.
ISBN 0-13-158591-6.
Descartes' Epistemology (Stanford Encyclopedia of
Philosophy)
René Descartes (1596–1650) is widely regarded as the father of
modern philosophy. His noteworthy contributions extend to
mathematics and physics. This entry focuses on his philosophical
contributions in the theory of knowledge. Specifically, the focus
is on the epistemological project of Descartes' famous work,
Meditations on First Philosophy. Upon its completion, the work was
circulated to other philosophers for their comments and criticisms.
Descartes responded with detailed replies that provide a rich
source of further information about the original work. He indeed
published the first edition (1641) of the Meditations together with
six sets of objections and replies, adding a seventh set with the
second edition (1642).
1. Conception of Knowledge
1.1 Analysis of Knowledge
Famously, Descartes defines knowledge in terms of doubt. While
distinguishing rigorous knowledge (scientia) and lesser grades of
conviction (persuasio), Descartes writes:
I distinguish the two as follows: there is conviction when
there remains some reason which might lead us to doubt, but
knowledge is conviction based on a reason so strong that it can
never be shaken by any stronger reason. (1640 letter, AT
3:64–65)
Elsewhere, while answering a challenge as to whether he
succeeds in founding such knowledge, Descartes writes:
But since I see that you are still stuck fast in the doubts
which I put forward in the First Meditation, and which I thought I
had very carefully removed in the succeeding Meditations, I shall
now expound for a second time the basis on which it seems to me
that all human certainty can be founded.
First of all, as soon as we think that we correctly perceive
something, we are spontaneously convinced that it is true. Now if
this conviction is so firm that it is impossible for us ever to
have any reason for doubting what we are convinced of, then there
are no further questions for us to ask: we have everything that we
could reasonably want. … For the supposition which we are making
here is of a conviction so firm that it is quite incapable of being
destroyed; and such a conviction is clearly the same as the most
perfect certainty. (Replies 2, AT 7:144–45)
These passages (and others) clarify that Descartes understands
doubt as the contrast of certainty. As my certainty increases, my
doubt decreases; conversely, as my doubt increases, my certainty
decreases. The requirement that knowledge is to be based in
complete, or perfect certainty, amounts to requiring a complete
absence of doubt — an indubitability, or inability to undermine
one's conviction. Descartes' methodic emphasis on doubt, rather
than on certainty, marks an epistemological innovation. This
so-called ‘method of doubt’ will be discussed below (Section
2).
The certainty/indubitability of interest to Descartes is
psychological in character, though not merely psychological — not
simply an inexplicable feeling. It has also a distinctively
epistemic character, involving a kind of rational insight. During
moments of certainty, it is as if my perception is guided by “a
great light in the intellect” (Med. 4, AT 7:59). This rational
illumination empowers me to “see utterly clearly with my mind's
eye”; my feelings of certainty are grounded — indeed, “I see a
manifest contradiction” in denying the proposition of which I'm
convinced. (Med. 3, AT 7:36)
Should we regard Descartes' account as a version of the
justified true belief analysis of knowledge tracing back to Plato?
The above texts (block quoted) are among Descartes' clearest
statements concerning the brand of knowledge he seeks. Yet they
raise questions about the extent to which his account is continuous
with other analyses of knowledge. Prima facie, his
characterizations imply a justified belief analysis of knowledge —
or in language closer to his own (and where justification is
construed in terms of unshakability), an unshakable conviction
analysis. There's no stated requirement that the would-be knower's
conviction is to be true, as opposed to being unshakably certain.
Is truth, therefore, not a requirement of Descartes' brand of
strict knowledge?
Many will balk at the suggestion. For in numerous texts
Descartes writes about truth, even characterizing a “rule for
establishing the truth” (Med. 5, AT 7:70, passim). It might
therefore seem clear, whatever else is the case, that Descartes
conceives of knowledge as advancing truth. Without denying this,
let me play devil's advocate. It is not inconsistent to hold that
we're pursuing the truth, even succeeding in establishing the
truth, and yet to construe the conditions of success wholly in
terms of the certainty of our conviction. Thus construed, to
establish a proposition just is to perceive it with certainty; the
result of having established it — i.e., what gets established — is
the proposition's truth. Note again that Descartes says, of the
perfect certainty he seeks, that it provides “everything that we
could reasonably want,” adding (in the same passage):
What is it to us that someone may make out that the perception
whose truth we are so firmly convinced of may appear false to God
or an angel, so that it is, absolutely speaking, false? Why should
this alleged “absolute falsity” bother us, since we neither believe
in it nor have even the smallest suspicion of it? (Replies 2, AT
7:144–45)
On one reading of this remark, Descartes is explicitly
embracing the consequence of having defined knowledge wholly in
terms of unshakable conviction: he's conceding that achieving the
brand of knowledge he seeks is compatible with being — “absolutely
speaking” — in error. If this is the correct reading, the
interesting upshot is that Descartes' ultimate aspiration is not
absolute truth, but absolute certainty.
On a quite different reading of this passage, Descartes is
clarifying that the analysis of knowledge is neutral not about
truth, but about absolute truth: he's conveying that the truth
condition requisite to knowledge involves truth as coherence.
A definitive interpretation of these issues has yet to gain
general acceptance in the literature. What is clear is that the
brand of knowledge Descartes seeks requires, at least, unshakably
certain conviction. Perhaps this seeming preoccupation with having
the right kind of certainty — including its being available to
introspection — is linked with an internalist conception of
knowledge.
1.2 Internalism and Justification
One way to divide up theories of justification is in terms of
the internalism-externalism distinction. Very roughly: a theory of
epistemic justification is internalist insofar as it requires that
the justifying factors are accessible to the knower's conscious
awareness; it is externalist insofar as it does not impose this
requirement.
Descartes' internalism requires that all justifying factors
take the form of ideas. For he holds that ideas are, strictly
speaking, the only objects of immediate perception, or conscious
awareness. (More on the directness or immediacy of perception in
Section 5.2.) Independent of this theory of ideas, Descartes'
methodical doubts underwrite an assumption with similar force: for
almost the entirety of the Meditations, his meditator-spokesperson
— hereafter referred to as the ‘meditator’ — adopts the assumption
that all his thoughts and experiences are occurring in a dream.
This assumption is tantamount to requiring that justification come
in the form of ideas.
An important consequence of the interpretation here being
developed — namely, a traditional representationalist reading of
Descartes — is that rigorous philosophical inquiry must proceed via
an inside-to-out strategy. This strategy is assiduously followed in
the Meditations, and it endures as a hallmark of many early modern
epistemologies. Ultimately, all judgments are grounded in an
inspection of the mind's ideas. Philosophical inquiry is, properly
understood, an investigation of ideas. The methodical strategy of
the Meditations has the effect of forcing readers to adopt this
mode of inquiry.
In recent years, some commentators have questioned this
traditional way of understanding the mediating role of ideas in
Descartes' philosophy. Noteworthy in this regard is John Carriero's
outstanding commentary on the Meditations (2009) which provides a
challenge to the kind account developed in the present essay.
1.3 Indefeasibility in Context
In characterizing knowledge as “incapable of being destroyed,”
Descartes portrays knowledge as enduring. Our conviction must be,
writes Descartes, “so strong that it can never be shaken”; “so firm
that it is impossible for us ever to have any reason for doubting.”
Descartes wants a brand of certainty/indubitability that is of the
highest rank, both in terms of degree and durability. He wants
knowledge that is utterly indefeasible. (Sceptical doubts count as
defeaters.)
This indefeasibility requirement implies more than mere
stability. A would-be knower could achieve stability simply by
never reflecting on reasons for doubt. But this would result in
mere undoubtedness, not indubitability. Referring to such a person,
Descartes points out that although a reason for “doubt may not
occur to him, it can still crop up if someone else raises the point
or if he looks into the matter himself” (Replies 2, AT
7:141).
Many readers conclude that Descartes' standards of
justification are too high, for they have the consequence that
almost nothing we ordinarily count as knowledge measures up. Before
jumping to this conclusion, we should put the indefeasibility
requirement into context.
Descartes is a contextualist in the sense that he allows that
different standards of justification are appropriate to different
contexts. This is not merely to say the obvious: that depending on
the context of inquiry, knowledge-worthy justification will
sometimes be needed, but other times not. It's to say something
stronger: that depending on the context of inquiry, the standards
of knowledge-worthy justification might vary. For example, a
contextualist might accept that ‘knowledge’-talk is equally
appropriate whether one is describing the best achievements of
empirical science, or the best achievements of mathematics, while
acknowledging that the former rest on weaker standards of proof
than the latter. This example is potentially misleading, in that
Descartes appears loath to count mere empirical evidence as
knowledge-worthy justification. But upon ramping up the standard to
what he finds minimally acceptable, the standard admits of context
dependent variation.
Descartes' minimum standard targets the level of certainty
arising when the mind's perception is both clear and distinct. (For
Descartes, clarity contrasts with obscurity, and distinctness
contrasts with confusion.) He allows that judgments grounded in
clear and distinct perception are defeasible (at least, for those
who've not yet read the Meditations). But he regularly
characterizes defeasible judgments at this level of certainty using
terminology (e.g., ‘cognitio’ and its cognates) that translates
well into the English ‘knowledge’ (and its cognates).
In the context of inquiry at play in the Meditations,
Descartes insists on indefeasibility. (Typically, he reserves the
term ‘scientia’ for this brand of knowledge, though he uses
‘cognitio’ and its cognates for either context.) Descartes' aim is,
once and for all, to lay a lasting foundation for knowledge. To
achieve this, he contends that we “cannot possibly go too far in
[our] distrustful attitude” (Med. 1, AT 7:22). Better to have a
standard that excludes some truths, than one that justifies some
falsehoods.
An interesting thesis emerges — call it the ‘No Atheistic
Knowledge Thesis’. Descartes maintains that though atheists are
quite capable of impressive knowledge, including in mathematics,
they are incapable of the indefeasible brand of knowledge he
seeks:
The fact that an atheist can be “clearly aware [clare
cognoscere] that the three angles of a triangle are equal to two
right angles” is something I do not dispute. But I maintain that
this awareness [cognitionem] of his is not true knowledge
[scientiam], since no act of awareness [cognitio] that can be
rendered doubtful seems fit to be called knowledge [scientia]. Now
since we are supposing that this individual is an atheist, he
cannot be certain that he is not being deceived on matters which
seem to him to be very evident (as I fully explained). (Replies 2,
AT 7:141)
Hereafter, I refer to the indefeasible brand of knowledge
Descartes seeks as ‘Knowledge’ (uppercase ‘K’).
1.4 Methodist Approach
How is the would-be Knower to proceed in identifying
candidates for Knowledge? Distinguish particularist and methodist
responses to the question. The particularist is apt to trust our
prima facie intuitions regarding particular knowledge claims. These
intuitions may then be used to help identify more general epistemic
principles. The methodist, in contrast, is apt to distrust our
prima facie intuitions. The preference is instead to begin with
general principles about proper method. The methodical principles
may then be used to arrive at settled, reflective judgments
concerning particular knowledge claims.
Famously, Descartes is in the methodist camp. Those who
haphazardly “direct their minds down untrodden paths” are sometimes
“lucky enough in their wanderings to hit upon some truth,” but “it
is far better,” writes Descartes, “never to contemplate
investigating the truth about any matter than to do so without a
method” (Rules 4, AT 10:371). Were we to rely on our prima facie
intuitions, we might suppose it obvious that the earth is unmoved,
or that ordinary objects (as tables and chairs) are just as just as
they seem. Yet, newly emerging mechanist doctrines of the 17th
century imply that these suppositions are false. Such cases
underscore the unreliability of our prima facie intuitions and the
need for a method by which to distinguish truth and falsity.
Descartes' view is not that all our pre-reflective intuitions
are mistaken. He concedes that “no sane person has ever seriously
doubted” such particular claims as “that there really is a world,
and that human beings have bodies” (Synopsis, AT 7:16). But
pre-reflective such judgments may be ill-grounded, even when
true.
The dialectic of the First Meditation features a confrontation
between particularism and methodism, with methodism emerging the
victor. For example, the meditator (while voicing empiricist
sensibilities) puts forward, as candidates for the foundations of
Knowledge, such prima facie obvious claims as “that I am here,
sitting by the fire, wearing a winter dressing-gown, holding this
piece of paper in my hands, and so on” — particular matters “about
which doubt is quite impossible,” or so it would seem (AT 7:18). In
response (and at each level of the dialectic), Descartes invokes
his own methodical principles to show that the prima facie
obviousness of such particular claims is insufficient to meet the
burden of proof.
1.5 Innate Ideas
Descartes' commitment to innate ideas places him in a
rationalist tradition tracing back to Plato. Knowledge of the
nature of reality derives from ideas of the intellect, not the
senses. An important part of metaphysical inquiry therefore
involves learning to think with the intellect. Plato's allegory of
the cave portrays this rationalist theme in terms of epistemically
distinct worlds: what the senses reveal is likened to shadowy
imagery on the wall of a poorly lit cave — what the intellect
reveals is likened to a world of fully real beings illuminated by
bright sunshine. The metaphor aptly depicts our epistemic
predicament on Descartes' own doctrines. An important function of
his methods is to help would-be Knowers redirect their attention
from the confused imagery of the senses, to the luminous world of
the intellect's clear and distinct ideas.
Further comparisons arise with Plato's doctrine of
recollection. The Fifth Meditation meditator remarks — having
applied Cartesian methodology, thereby discovering innate truths
within: “on first discovering them it seems that I am not so much
learning something new as remembering what I knew before” (Med. 5,
AT 7:64). Elsewhere Descartes adds, of innate truths:
[W]e come to know them by the power of our own native
intelligence, without any sensory experience. All geometrical
truths are of this sort — not just the most obvious ones, but all
the others, however abstruse they may appear. Hence, according to
Plato, Socrates asks a slave boy about the elements of geometry and
thereby makes the boy able to dig out certain truths from his own
mind which he had not previously recognized were there, thus
attempting to establish the doctrine of reminiscence. Our knowledge
of God is of this sort. (1643 letter, AT 8b:166–67)
The famous wax thought experiment of the Second Meditation is
supposed to illustrate (among other things) a procedure to “dig
out” what is innate. The thought experiment purports to help the
meditator achieve a “purely mental scrutiny,” thereby apprehending
more easily the innate idea of body. (Med. 2, AT 7:30–31) According
to Descartes, our minds come stocked with a variety of intellectual
concepts — ideas whose content derives solely from the nature of
the mind. This storehouse includes ideas in mathematics, logic, and
metaphysics. Interestingly, Descartes holds that even our sensory
ideas involve innate content. On his understanding of the new
mechanical physics, bodies have no real properties resembling our
sensory ideas of colors, sounds, tastes, and the like, thus
implying that the content of such ideas draws from the mind itself.
Unlike purely intellectual concepts, however, the formation of
these sensory ideas depends on sensory stimulation. Elsewhere
(2006), I argue that on Descartes' official doctrine, ideas are
innate insofar as their content derives from the nature of the mind
alone, as opposed to deriving from sense experience. This
characterization allows that both intellectual and sensory concepts
draw on native resources, though not to the same extent.
Though the subject of rationalism in Descartes' epistemology
deserves careful attention, the present essay generally focuses on
Descartes' efforts to achieve indefeasible Knowledge. Relatively
little attention is given to his doctrines of innateness, or, more
generally, his ontology of thought.
Further reading: On the internalism-externalism distinction,
see Alston (1989) and Plantinga (1993). For a partly externalist
interpretation of Descartes, see Della Rocca (2005). For
coherentist interpretations of Descartes' project, see Frankfurt
(1970) and Sosa (1997a). For a stability interpretation of
Descartes, see Bennett (1990). On the indefeasibility of Knowledge,
see Newman and Nelson (1999). On contextualism in Descartes, see
Newman (2004). On the methodism-particularism distinction, see
Chisholm (1982). On Descartes' rationalism, see Adams (1975),
Jolley (1990), and Newman (2006).
2. Methods: Foundationalism and Doubt
Of his own methodology, Descartes writes:
Throughout my writings I have made it clear that my method
imitates that of the architect. When an architect wants to build a
house which is stable on ground where there is a sandy topsoil over
underlying rock, or clay, or some other firm base, he begins by
digging out a set of trenches from which he removes the sand, and
anything resting on or mixed in with the sand, so that he can lay
his foundations on firm soil. In the same way, I began by taking
everything that was doubtful and throwing it out, like sand …
(Replies 7, AT 7:537)
The theory whereby items of knowledge are best organized on an
analogy to architecture traces back to ancient Greek thought — to
Aristotle, and to work in geometry. That Descartes' method
effectively pays homage to Aristotle is, of course, welcome by his
Aristotelian audience. But Descartes views Aristotle's
foundationalist principles as incomplete, at least when applied to
metaphysical inquiry. I suggest that his method of doubt is
intended to complement foundationalism. The two methods are
supposed to work in cooperation, as conveyed in the above
quotation. Let's consider each method.
2.1 Foundationalism
The central insight of foundationalism is to organize
knowledge in the manner of a well-structured, architectural
edifice. Such an edifice owes its structural integrity to two kinds
of features: a firm foundation and a superstructure of support
beams firmly anchored to the foundation. A system of justified
beliefs might be organized by two analogous features: a foundation
of unshakable first principles, and a superstructure of further
propositions anchored to the foundation via unshakable
inference.
Exemplary of a foundationalist system is Euclid's geometry.
Euclid begins with a foundation of first principles — definitions,
postulates, and axioms or common notions — on which he then bases a
superstructure of further propositions. Descartes' own designs for
metaphysical Knowledge are inspired by Euclid's system:
Those long chains composed of very simple and easy reasoning,
which geometers customarily use to arrive at their most difficult
demonstrations, had given me occasion to suppose that all the
things which can fall under human knowledge are interconnected in
the same way. (Discourse 2, AT 6:19).
It would be misleading to characterize the arguments of the
Meditations as unfolding straightforwardly according to geometric
method. But Descartes maintains that they can be reconstructed as
such, and he expressly does so at the end of the Second Replies —
providing a “geometrical” exposition of his central constructive
steps, under the following headings: definitions, postulates,
axioms or common notions, and propositions (AT 7:160ff).
As alluded to above, the Meditations contains a destructive
component that Descartes likens to the architect's preparations for
laying a foundation. Though the component finds no analogue in the
method of the geometers, Descartes appears to hold that this
component is needed in metaphysical inquiry. The discovery of
Euclid's first principles (some of them, at any rate) is
comparatively unproblematic: such principles as that things which
are equal to the same thing are also equal to one another (one of
Euclid's axioms) accord not only with reason, but with the senses.
In contrast, metaphysical inquiry might have first principles that
conflict with the senses:
The difference is that the primary notions which are
presupposed for the demonstration of geometrical truths are readily
accepted by anyone, since they accord with the use of our senses.
Hence there is no difficulty there, except in the proper deduction
of the consequences, which can be done even by the less attentive,
provided they remember what has gone before. … In metaphysics by
contrast there is nothing which causes so much effort as making our
perception of the primary notions clear and distinct. Admittedly,
they are by their nature as evident as, or even more evident than,
the primary notions which the geometers study; but they conflict
with many preconceived opinions derived from the senses which we
have got into the habit of holding from our earliest years, and so
only those who really concentrate and meditate and withdraw their
minds from corporeal things, so far as possible, will achieve
perfect knowledge of them. (Replies 2, AT 7:156–57)
Among Descartes' persistent themes is that such preconceived
opinions can have the effect of obscuring our mental vision of
innate principles; that where there are disputes about first
principles, it is not “because one man's faculty of knowledge
extends more widely than another's, but because the common notions
are in conflict with the preconceived opinions of some people who,
as a result, cannot easily grasp them”; whereas, “we cannot fail to
know them [innate common notions] when the occasion for thinking
about them arises, provided that we are not blinded by preconceived
opinions” (Prin. 1:49–50, AT 8a:24). These “preconceived opinions”
must be “set aside,” says Descartes, “in order to lay the first
foundations of philosophy” (1643 letter, AT 8b:37). Unless they are
set aside, we're apt to regard — as first principles — the mistaken
(though prima facie obvious) sensory claims that particularists
find attractive. Such mistakes in the laying of the foundations
weaken the entire edifice. Descartes adds:
All the mistakes made in the sciences happen, in my view,
simply because at the beginning we make judgements too hastily, and
accept as our first principles matters which are obscure and of
which we do not have a clear and distinct notion. (Search, AT
10:526)
Though foundationalism brilliantly allows for the expansion of
knowledge from first principles, Descartes thinks that a
complementary method is needed to help us discover genuine first
principles. He devises the method of doubt for this purpose — a
method to help “set aside” preconceived opinions.
2.2 Method of Doubt
Descartes opens the First Meditation asserting the need “to
demolish everything completely and start again right from the
foundations” (AT 7:17). The passage adds:
Reason now leads me to think that I should hold back my assent
from opinions which are not completely certain and indubitable just
as carefully as I do from those which are patently false. So, for
the purpose of rejecting all my opinions, it will be enough if I
find in each of them at least some reason for doubt. (AT
7:18)
In the architectural analogy, we can think of bulldozers as
the ground clearing tools of demolition. For Knowledge building,
Descartes construes sceptical doubts as the ground clearing tools
of epistemic demolition. Bulldozers undermine literal ground; doubt
undermines epistemic ground. Using sceptical doubts, the meditator
shows us how to find “some reason for doubt” in all our preexisting
opinions.
Descartes' ultimate aims, however, are constructive. Unlike
“the sceptics, who doubt only for the sake of doubting,” Descartes
aims “to reach certainty — to cast aside the loose earth and sand
so as to come upon rock or clay” (Discourse 3, AT 6:28–29).
Bulldozers are typically used for destructive ends, as are
sceptical doubts. Descartes' methodical innovation is to employ
demolition for constructive ends. Where a bulldozer's force
overpowers the ground, its effects are destructive. Where the
ground's firmness resists the bulldozer's force, the bulldozer
might be used constructively — using it to reveal the ground as
firm. Descartes' innovation is to use epistemic bulldozers in this
way. He uses sceptical doubts to test the firmness of candidates
put forward for the foundations of Knowledge.
According to at least one prominent critic, this employment of
sceptical doubt is unnecessary and excessive. Writes
Gassendi:
There is just one point I am not clear about, namely why you
did not make a simple and brief statement to the effect that you
were regarding your previous knowledge as uncertain so that you
could later single out what you found to be true. Why instead did
you consider everything as false, which seems more like adopting a
new prejudice than relinquishing an old one? This strategy made it
necessary for you to convince yourself by imagining a deceiving God
or some evil demon who tricks us, whereas it would surely have been
sufficient to cite the darkness of the human mind or the weakness
of our nature. (Objs. 5, AT 7:257–58; my italics)
Here, Gassendi singles out two features of methodic doubt —
its universal and hyperbolic character. In reply, Descartes
remarks:
You say that you approve of my project for freeing my mind
from preconceived opinions; and indeed no one can pretend that such
a project should not be approved of. But you would have preferred
me to have carried it out by making a “simple and brief statement”
— that is, only in a perfunctory fashion. Is it really so easy to
free ourselves from all the errors which we have soaked up since
our infancy? Can we really be too careful in carrying out a project
which everyone agrees should be performed? (Replies 5, AT
7:348)
Evidently, Descartes holds that the universal and hyperbolic
character of methodic doubt is helpful to its success. Further
appeal to the architectural analogy helps elucidate why.
Incorporating these features enables the method to more effectively
identify first principles. Making doubt universal and hyperbolic
helps to distinguish genuine unshakability from the mere appearance
of it.
Consider first the universal character of doubt — the need “to
demolish everything completely and start again right from the
foundations” (Med. 1, AT 7:17). The point is not merely to apply
doubt to all candidates for Knowledge, but to apply doubt
collectively. Descartes offers the following analogy:
Suppose [a person] had a basket full of apples and, being
worried that some of the apples were rotten, wanted to take out the
rotten ones to prevent the rot spreading. How would he proceed?
Would he not begin by tipping the whole lot out of the basket? And
would not the next step be to cast his eye over each apple in turn,
and pick up and put back in the basket only those he saw to be
sound, leaving the others? In just the same way, those who have
never philosophized correctly have various opinions in their minds
which they have begun to store up since childhood, and which they
therefore have reason to believe may in many cases be false. They
then attempt to separate the false beliefs from the others, so as
to prevent their contaminating the rest and making the whole lot
uncertain. Now the best way they can accomplish this is to reject
all their beliefs together in one go, as if they were all uncertain
and false. They can then go over each belief in turn and re-adopt
only those which they recognize to be true and indubitable.
(Replies 7, AT 7:481)
That even one falsehood would be mistakenly treated as a
genuine first principle — say, the belief that the senses are
reliable, or that ancient authorities should be trusted — threatens
to spread falsehood to other beliefs in the system. A collective
doubt helps avoid such mistakes. It ensures that the method only
approves candidate first principles that are unshakable in their
own right: it rules out that the appearance of unshakability is
owed to logical relations with other principles, themselves not
subjected to doubt.
How is the hyperbolic character of methodic doubt supposed to
contribute to the method's success? The architectural analogy is
again helpful. Suppose that an architect is vigilant in employing a
universal/collective doubt. Suppose, further, that she attempts to
use bulldozers for constructive purposes. A problem nonetheless
arises. How big a bulldozer is she to use? A light-duty bulldozer
might be unable to distinguish a medium-sized boulder, and
immovable bedrock. In both cases, the ground would appear
immovable. The solution lies in using not light-duty, but
heavy-duty tools of demolition — the bigger the bulldozer, the
better. The lesson is clear for the epistemic builder: the more
hyperbolic the doubt, the better.
A potential problem remains. Does not the problem of the
“light-duty bulldozer” repeat itself? No matter how firm one's
ground, would it not be dislodged in the face of a yet bigger
bulldozer? This raises the worry that there might not be unshakable
ground, but only that which is yet unshaken. Descartes' goal of
utterly indubitable epistemic ground may simply be elusive.
Perhaps the architectural analogy breaks down in a manner that
serves Descartes well. For though there is no most-powerful literal
bulldozer, perhaps epistemic bulldozing is not subject to this
limitation. Descartes seems to think that there is a most-powerful
doubt — a doubt than which none more hyperbolic can be conceived.
The Evil Genius Doubt (and equivalent doubts) is supposed to fit
the bill. If the method reveals epistemic ground that stands fast
in the face of a doubt this hyperbolic, then, as Descartes seems to
hold, this counts as epistemic bedrock if anything does.
Hence the importance of the universal and hyperbolic character
of the method of doubt. Gassendi's suggestion that we forego
methodic doubt in favor of a “simple and brief statement to the
effect that [we're] regarding [our] previous knowledge as
uncertain” misses the intended point of methodic doubt.
Before turning attention to the First Meditation demolition
project, I want to address what I believe are significant
misconceptions about the method of doubt. Two of these are
suggested in a passage from the pragmatist Peirce:
We cannot begin with complete doubt. We must begin with all
the prejudices which we actually have when we enter upon the study
of philosophy. These prejudices are not to be dispelled by a maxim
[viz., the maxim that the philosopher “must begin with universal
doubt”], for they are things which it does not occur to us can be
questioned. Hence this initial skepticism will be a mere
self-deception, and not real doubt … A person may, it is true, in
the course of his studies, find reason to doubt what he began by
believing; but in that case he doubts because he has a positive
reason for it, and not on account of the Cartesian maxim. Let us
not pretend to doubt in philosophy what we do not doubt in our
hearts. (1955, 228f)
It is a misconception that universal doubt is intended to
result from the mere effort to adhere to the maxim — as if by sheer
effort of will. To the contrary, Descartes introduces sceptical
arguments precisely in acknowledgement that we need reasons for
doubt:
I did say that there was some difficulty in expelling from our
belief everything we have previously accepted. One reason for this
is that before we can decide to doubt, we need some reason for
doubting; and that is why in my First Meditation I put forward the
principal reasons for doubt. (Replies 5, appendix, AT 9a:204)
Another misconception is suggested by Peirce's reference to a
“doubt in our hearts.” Distinguish two kinds of doubt, in terms of
two kinds of ways that doubt can defeat knowledge. Some doubts
purport to undermine one's conviction or belief — call these
‘belief-defeating doubts’. Other doubts purport to undermine one's
justification (whether or not they undermine belief) — call these
‘justification-defeating doubts’. What Peirce calls a ‘doubt in our
hearts’ is suggestive of a belief-defeating doubt. The resulting
misconception is that only belief-defeating doubts can undermine
knowledge. Longstanding traditions in philosophy acknowledge that
there may be truths we believe in our hearts (as it were), but
which we do not know. This is one of the lessons of methodic doubt.
The sceptical doubts are supposed to help us appreciate that though
we believe that 2+3=5, and believe that we're awake, and believe
that there is an external world, we may nonetheless lack Knowledge.
Justification-defeating doubts are sufficient to undermine
Knowledge, and this is the sort of doubt that Descartes puts
forward.
A related misconception has the method calling not merely for
doubt, but for disbelief or dissent. One of Gassendi's objections
reads in this manner. He seems to take Descartes to be urging us,
quite literally, to “consider everything as false,” a strategy
which, as he says to Descartes, “made it necessary for you to
convince yourself” of the sceptical hypotheses (Objs. 5, AT
7:257–58). But Descartes' method does not require us to dissent
from the beliefs it undermines. Surely the spirit (even if not
always the letter) of the invocation to doubt is that we are to
“hold back [our] assent from opinions which are not completely
certain and indubitable just as carefully as [we] do from those
which are patently false” (Med. 1, AT 7:18).
Finally, a common misconception has it that the universality
of doubt undermines the method of doubt itself, since the sceptical
hypotheses themselves are so dubious. But this misses the point of
the method: namely, to extend doubt universally to candidates for
Knowledge, but not also to the very tools for founding Knowledge.
As Descartes concedes: “there may be reasons which are strong
enough to compel us to doubt, even though these reasons are
themselves doubtful, and hence are not to be retained later on”
(Replies 7, AT 7:473–74).
Further reading: On foundationalism: for Descartes' treatment,
see Discourse, First Meditation, and Seventh Objections and
Replies; for its treatment by ancients, see Euclid (1956) and
Aristotle (Posterior Analytics); by interpreters of Descartes, see
Sosa (1997a) and Van Cleve (1979). On Cartesian inference, see
Gaukroger (1989) and Hacking (1980). On methodical doubt: for
Descartes' treatment, see Rules, Discourse, First Meditation, and
Seventh Replies; by commentators, see Frankfurt (1970), Garber
(1986), Newman (2006), Williams (1983), and Wilson (1978). On
needing reasons for doubt (nonvoluntarism), see Newman (2007). On
the analysis-synthesis distinction (closed related to issues of
doubt and methodology): see the Second Replies (AT 7:155ff); see
also Galileo (1967, 50f), Arnauld (1964, 4:2–3), Curley (1986), and
Hintikka (1978).
3. First Meditation Doubting Arguments
3.1 Dreaming Doubt
Historically, there are at least two distinct dream-related
doubts. The one doubt undermines the judgment that I am presently
awake — call this the ‘Now Dreaming Doubt’. The other doubt
undermines the judgment that I am ever awake (i.e., in the way
normally supposed) — call this the ‘Always Dreaming Doubt’. A
textual case can be made on behalf of both formulations being
raised in the Meditations.
Both doubts appeal to some version of the thesis that the
experiences we take as dreams are (at their best) qualitatively
similar to those we take as waking — call this the ‘Similarity
Thesis’. The Similarity Thesis may be formulated in a variety of
strengths. A strong Similarity Thesis might contend that some
dreams are experientially indistinguishable from waking, even
subsequent to waking-up; a weaker thesis might contend merely that
dreams seem similar to waking while having them, but not upon
waking. Debates about precisely how similar waking and dreaming can
be, have raged for more than two millennia. The tone of the debates
suggests that the degree of qualitative similarity may vary across
individuals (or, at least, across their recollections of dreams).
Granting such variation, dreaming doubts that depend on weaker
versions of the Similarity Thesis are (other things equal) apt to
be more persuasive. I want to consider a textually defensible
formulation that is relatively weak. (Note, however, that some
texts suggest a strong thesis: “As if I did not remember other
occasions when I have been tricked by exactly similar thoughts
while asleep” (Med. 1, AT 7:19, my italics).)
The relatively weak thesis I have in mind is this: that the
similarity between waking and dreaming is sufficient to render it
thinkable that a dream experience would seem realistic, even when
reflecting on the experience, while having it. As Descartes writes:
“every sensory experience I have ever thought I was having while
awake I can also think of myself as sometimes having while asleep”
(Med. 6, AT 7:77). This version of the Similarity Thesis is
endorsable by those who never recollect dreams that seem, on
hindsight, experientially indistinguishable from waking; indeed,
it's endorsable even by those who simply do not remember their
dreams to any significant degree.
This weak Similarity Thesis is sufficient to generate
straightaway the Now Dreaming Doubt. Since it is thinkable that a
dream would convincingly seem as realistic (while having it) as my
present experience seems, then, for all I Know, I am now
dreaming.
Recall that Descartes' method requires only a
justification-defeating doubt, not a belief-defeating doubt. The
method requires me to appreciate that my present belief (that I'm
awake) is not sufficiently justified. It does not require that I
give up that belief. (I might continue to hold it on some merely
psychological grounds.) Nor does the belief need to be false — I
might, in fact, be awake. The Now Dreaming Doubt does its epistemic
damage so long as it undermines my reasons for believing I'm awake
— i.e., so long as I find it thinkable that a dream would seem this
good. The First Meditation makes a case that this is indeed
thinkable. As Descartes writes: “there are never any sure signs by
means of which being awake can be distinguished from being asleep”
(Med. 1, AT 7:19).
The conclusion — that I don't Know that I'm now awake — has
widespread sceptical consequences. For if I don't Know this, then
neither do I Know that I'm now “holding this piece of paper in my
hands,” to cite an example the meditator had supposed to be “quite
impossible” to doubt. Reflection on the Now Dreaming Doubt changes
his mind. He comes around to the view that, for all he Knows, the
sensible objects of his present experience are mere figments of a
vivid dream.
Much ado has been made about whether dreaming arguments are
self-refuting. According to an influential objection, Similarity
Theses presuppose that we can reliably distinguish dreams and
waking, yet the conclusion of dreaming arguments presupposes that
we cannot. Therefore, if the conclusion of such an argument is
true, then the premise stating the Similarity Thesis cannot be.
Some formulations of the thesis do make this mistake. Of present
interest is whether all do — specifically, whether Descartes makes
the mistake. He does not. Interestingly, his formulation
presupposes simply the truism that we do in fact distinguish
dreaming and waking (never mind whether reliably). He states his
version of the thesis in terms of what we think of as dreams,
versus what we think of as waking: “every sensory experience I have
ever thought I was having while awake I can also think of myself as
sometimes having while asleep” (Med. 6, AT 7:77). This formulation
avoids the charge of self-refutation, for it is compatible with the
conclusion that we cannot reliably distinguish dreams and
waking.
Does Descartes also put forward a second dreaming argument,
the Always Dreaming Doubt? I believe there is strong textual
evidence to support this, though it is by no means the standard
interpretation. (I make a case for this interpretation in my 1994.)
The conclusion of the Always Dreaming Doubt is generated from the
very same Similarity Thesis, together with a further sceptical
assumption, namely: that for all I Know, the processes producing
what I take as waking are no more veridical than those producing
what I take as dreams. As Descartes writes:
[E]very sensory experience I have ever thought I was having
while awake I can also think of myself as sometimes having while
asleep; and since I do not believe that what I seem to perceive in
sleep comes from things located outside me, I did not see why I
should be any more inclined to believe this of what I think I
perceive while awake. (Med. 6, AT 7:77)
The aim of the Always Dreaming Doubt is to undermine not
whether I'm now awake, but whether “sensation” is produced by
external objects even on the assumption I'm now awake. For in the
cases of both waking and dreaming, my cognitive access extends only
to the productive result, but not the productive process. On what
basis, then, do I conclude that the productive processes are
different — that external objects play more of a role in waking
than in dreaming? For all I Know, both sorts of experience are
produced by some subconscious faculty of my mind. As Descartes has
his meditator say:
[T]here may be some other faculty [of my mind] not yet fully
known to me, which produces these ideas without any assistance from
external things; this is, after all, just how I have always thought
ideas are produced in me when I am dreaming. (Med. 3, AT
7:39)
The sceptical consequences of the Always Dreaming Doubt are
even more devastating than those of the Now Dreaming Doubt. If I do
not Know that “normal waking” experience is produced by external
objects, then, for all I Know, all of my experiences might be
dreams of a sort. For all I Know, there might not be an external
world. My best evidence of an external world derives from my
preconceived opinion that external world objects produce my waking
experiences. Yet the Always Dreaming Doubt calls this into
question:
All these considerations are enough to establish that it is
not reliable judgement but merely some blind impulse that has made
me believe up till now that there exist things distinct from myself
which transmit to me ideas or images of themselves through the
sense organs or in some other way. (Med. 3, AT 7:39–40)
The two dreaming doubts are parasitic on the same Similarity
Thesis, though their sceptical consequences differ. The Now
Dreaming Doubt raises the universal possibility of delusion: for
any one of my sensory experiences, it is possible (for all I Know)
that the experience is delusive. The Always Dreaming Doubt raises
the possibility of universal delusion: it is possible (for all I
Know) that all my sensory experiences are delusions (say, from a
God's-eye perspective).
3.2 Evil Genius Doubt
Though dreaming doubts do significant demolition work, they
are light-duty bulldozers relative to Descartes' most power
sceptical doubt. What further judgments are left to be undermined?
Following the discussion of dreaming, the meditator tentatively
concludes that the results of empirical disciplines “are doubtful”
— e.g., “physics, astronomy, medicine,” and the like.
Whereas:
[A]rithmetic, geometry and other subjects of this kind, which
deal only with the simplest and most general things, regardless of
whether they really exist in nature or not, contain something
certain and indubitable. For whether I am awake or asleep, two and
three added together are five, and a square has no more than four
sides. It seems impossible that such transparent truths should
incur any suspicion of being false. (Med. 1, AT 7:20)
In the final analysis, Descartes holds that such transparent
truths — along with demonstrable truths, and many judgments of
internal sense — are indeed Knowable. To become actually Known,
however, they must stand unshakable in the face the most powerful
of doubts. The stage is thus set for the introduction of another
sceptical hypothesis.
The most famous rendering of Descartes' most hyperbolic doubt
takes the form of the Evil Genius Doubt. Suppose I am the creation
of a powerful but malicious being. This “evil genius” (or deceiving
“God, or whatever I may call him,” AT 7:24) has given me flawed
cognitive faculties, such that I am in error even about
epistemically impressive matters — even the simple matters that
seem supremely evident. The suggestion is unbelievable, but not
unthinkable. It is intended as a justification-defeating doubt that
undermines our judgments about even the most simple and evident
matters.
Many readers of Descartes assume that the Evil Genius Doubt
draws its sceptical force from the “utmost power” attributed to the
deceiver. This is to misunderstand Descartes. He contends that an
equally powerful doubt may be generated on the opposite supposition
— namely, the supposition that I am not the creature of an
all-powerful being:
Perhaps there may be some who would prefer to deny the
existence of so powerful a God rather than believe that everything
else is uncertain. … yet since deception and error seem to be
imperfections, the less powerful they make my original cause, the
more likely it is that I am so imperfect as to be deceived all the
time. (Med. 1, AT 7:21).
Descartes makes essentially the same point in a parallel
passage of the Principles:
[W]e have been told that there is an omnipotent God who
created us. Now we do not know whether he may have wished to make
us beings of the sort who are always deceived even in those matters
which seem to us supremely evident … We may of course suppose that
our existence derives not from a supremely powerful God but either
from ourselves or from some other source; but in that case, the
less powerful we make the author of our coming into being, the more
likely it will be that we are so imperfect as to be deceived all
the time. (Prin. 1:5, AT 8a:6)
Descartes' official position is that the Evil Genius Doubt is
merely one among multiple hypotheses that can motivate the more
general hyperbolic doubt. Fundamentally, the doubt is about my
cognitive nature — about the possibility that my mind is flawed.
Descartes consistently emphasizes this theme throughout the
Meditations (italics added):
God could have given me a nature such that I was deceived even
in matters which seemed most evident. (Med. 3, AT 7:36)
I can convince myself that I have a natural disposition to go
wrong from time to time in matters which I think I perceive as
evidently as can be. (Med. 5, AT 7:70)
I saw nothing to rule out the possibility that my natural
constitution made me prone to error even in matters which seemed to
me most true. (Med. 6, AT 7:77)
What is essential to the doubt is not a specific story about
how I got my cognitive wiring; it's instead the realization —
regardless the story — that I can worry that my cognitive wiring is
flawed. Elsewhere, I have suggested that we name the underlying
doubt ‘Meta-Cognitive Doubt’, to make clear that it is
fundamentally about the implications of having a flawed cognitive
nature, rather than of being made by an omnipotent creator.
(Carriero makes a similar point with the name ‘imperfect-nature
doubt’ (2009, 27).) Even so, I regularly speak in terms of the evil
genius (following Descartes' lead), as a kind of mnemonic for the
more general doubt about our cognitive nature.
Having introduced the Evil Genius Doubt, the First Meditation
program of demolition is not only hyperbolic but universal. As the
meditator remarks, I “am finally compelled to admit that there is
not one of my former beliefs about which a doubt may not properly
be raised” (Med. 1, AT 7:21). As will emerge, the early paragraphs
of the Third Meditation clarify a further nuance of the Evil Genius
Doubt — a nuance consistently observed thereafter. Descartes
clarifies there that the Evil Genius Doubt operates in an indirect
manner, a topic to which we return (in Section 5.1).
Further reading: On Descartes' sceptical arguments, see
Bouwsma (1949), Curley (1978), Newman (1994), Newman and Nelson
(1999), Williams (1986 and 1995). For a contrary reading of the
Evil Genius Doubt, see Gewirth (1941) and Wilson (1978). For a more
general philosophical treatment of dreaming arguments, see Dunlap
(1977).
4. Cogito Ergo Sum
4.1 The First Item of Knowledge
Famously, Descartes puts forward a very simple candidate as
the “first item of knowledge.” The candidate is suggested by
methodic doubt — by the very effort at thinking all my thoughts
might be mistaken. Early in the Second Meditation, Descartes has
his meditator observe:
I have convinced myself that there is absolutely nothing in
the world, no sky, no earth, no minds, no bodies. Does it now
follow that I too do not exist? No: if I convinced myself of
something then I certainly existed. But there is a deceiver of
supreme power and cunning who is deliberately and constantly
deceiving me. In that case I too undoubtedly exist, if he is
deceiving me; and let him deceive me as much as he can, he will
never bring it about that I am nothing so long as I think that I am
something. So after considering everything very thoroughly, I must
finally conclude that this proposition, I am, I exist, is
necessarily true whenever it is put forward by me or conceived in
my mind. (Med. 2, AT 7:25)
As the canonical formulation has it, I think therefore I am.
(Latin: cogito ergo sum; French: je pense, donc je suis.) This
formulation does not expressly arise in the Meditations.
Descartes regards the ‘cogito’ (as I shall refer to it) as the
“first and most certain of all to occur to anyone who philosophizes
in an orderly way” (Prin. 1:7, AT 8a:7). Testing the cogito by
means of methodic doubt is supposed to reveal its unshakable
certainty. As earlier noted, the existence of my body is subject to
doubt. The existence of my thinking, however, is not. The very
attempt at thinking away my thinking is indeed
self-stultifying.
The cogito raises numerous philosophical questions and has
generated an enormous literature. In summary fashion, I'll try to
clarify a few central points.
First, a first-person formulation is essential to the
certainty of the cogito. Third-person claims, such as “Icarus
thinks,” or “Descartes thinks,” are not unshakably certain — not
for me, at any rate; only the occurrence of my thought has a chance
of resisting hyperbolic doubt. There are a number of passages in
which Descartes refers to a third-person version of the cogito. But
none of these occurs in the context of establishing the actual
existence of a particular thinker (in contrast with the
conditional, general result that whatever thinks exists).
Second, a present tense formulation is essential to the
certainty of the cogito. It's no good to reason that “I existed
last Tuesday, since I recall my thinking on that day.” For all I
Know, I'm now merely dreaming about that occasion. Nor does it work
to reason that “I'll continue to exist, since I'm now thinking.” As
the meditator remarks, “it could be that were I totally to cease
from thinking, I should totally cease to exist” (Med. 2, AT 7:27).
The privileged certainty of the cogito is grounded in the “manifest
contradiction” (cf. AT 7:36) of trying to think away my present
thinking.
Third, the certainty of the cogito depends on being formulated
in terms of my cogitatio — i.e., my thinking, or
awareness/consciousness more generally. Any mode of thinking is
sufficient, including doubting, affirming, denying, willing,
understanding, imagining, and so on (cf. Med. 2, AT 7:28). My
non-thinking activities, however, are insufficient. For instance,
it's no good to reason that “I exist, since I am walking,” because
methodic doubt calls into question the existence of my legs. Maybe
I'm just dreaming that I have legs. A simple revision, such as “I
exist since it seems I'm walking,” restores the anti-sceptical
potency (cf. Replies 5, AT 7:352; Prin. 1:9).
Fourth, a caveat is in order. That Descartes rejects
formulations presupposing the existence of a body commits him to no
more than an epistemic distinction between mind and body, but not
yet an ontological distinction (as in so-called mind-body dualism).
Indeed, in the passage following the cogito, Descartes has his
meditator say:
And yet may it not perhaps be the case that these very things
which I am supposing to be nothing [e.g., “that structure of limbs
which is called a human body”], because they are unknown to me, are
in reality identical with the “I” of which I am aware? I do not
know, and for the moment I shall not argue the point, since I can
make judgements only about things which are known to me. (Med. 2,
AT 7:27)
Fifth, and related to the foregoing quotation, is that
Descartes' reference to an “I”, in the “I think”, is not intended
to presuppose the existence of a substantial self. In the very next
sentence following the initial statement of the cogito, the
meditator says: “But I do not yet have a sufficient understanding
of what this ‘I’ is, that now necessarily exists” (Med. 2, AT
7:25). The cogito purports to yield certainty that I exist insofar
as I am a thinking thing, whatever that turns out to be. The
ensuing discussion is intended to help arrive at an understanding
of the ontological nature of the thinking subject.
More generally, we should distinguish issues of epistemic and
ontological dependence. In the final analysis, Descartes thinks he
shows that the occurrence of thought depends (ontologically) on the
existence of a substantial self — to wit, on the existence of an
infinite substance, namely God (cf. Med. 3, AT 7:48ff). But
Descartes denies that an acceptance of these ontological matters is
epistemically prior to the cogito: its certainty is not supposed to
depend (epistemically) on the abstruse metaphysics that Descartes
thinks he eventually establishes.
If the cogito does not presuppose a substantial self, what
then is the epistemic basis for injecting the “I” into the “I
think”? Some critics have complained that, in referring to the “I”,
Descartes begs the question by presupposing what he means to
establish in the “I exist.” Among the critics, Bertrand Russell
objects that “the word ‘I’ is really illegitimate”; that Descartes
should have, instead, stated “his ultimate premiss in the form
‘there are thoughts’.” Russell adds that “the word ‘I’ is
grammatically convenient, but does not describe a datum.” (1945,
567) Accordingly, “there is pain” and “I am in pain” have different
contents, and Descartes is entitled only to the former.
One effort at reply has it that introspection reveals more
than what Russell allows — it reveals the subjective character of
experience. On this view, there is more to the experiential story
of being in pain than is expressed by saying that there is pain:
the experience includes the feeling of pain plus a point-of-view —
an experiential addition that's difficult to characterize except by
adding that “I” am in pain, that the pain is mine. Importantly, my
awareness of this subjective feature of experience does not depend
on an awareness of the metaphysical nature of a thinking subject.
If we take Descartes to be using ‘I’ to signify this subjective
character, then he is not smuggling in something that's not already
there: the “I”-ness of consciousness turns out to be (contra
Russell) a primary datum of experience. Though, as Hume
persuasively argues, introspection reveals no sense impressions
suited to the role of a thinking subject, Descartes, unlike Hume,
has no need to derive all our ideas from sense impressions.
Descartes' idea of the self does ultimately draw on innate
conceptual resources.
Sixth, much of the debate over whether the cogito involves
inference, or is instead a simple intuition (roughly,
self-evident), is preempted by three observations. One observation
concerns the absence of an express ‘ergo’ (‘therefore’) in the
Second Meditation account. It seems a mistake to emphasize this
absence, as if suggesting that Descartes denies any role for
inference. For the Second Meditation passage is the one place (of
his various published treatments ) where Descartes explicitly
details a line of inferential reflection leading up to the
conclusion that I am, I exist. His other treatments merely say the
‘therefore’; the Meditations treatment unpacks it. A second
observation is that it seems a mistake to assume that the cogito
must either involve inference, or intuition, but not both. There is
no inconsistency in the view that the meditator comes to appreciate
the persuasive force of the cogito by means of inferential
reflection, while also holding that his eventual conviction is not
grounded in inference. A third observation is that what one intuits
might well include an inference: it is widely held among
philosophers today that modus ponens is self-evident, and yet it
contains an inference. There is no inconsistency in claiming a
self-evident grasp of a proposition with inferential structure — a
fact applicable to the cogito. As Descartes writes:
When someone says “I am thinking, therefore I am, or I exist,”
he does not deduce existence from thought by means of a syllogism,
but recognizes it as something self-evident by a simple intuition
of the mind. (Replies 2, AT 7:140)
4.2 But is it Knowledge?
There are interpretive disputes about whether the cogito is
supposed to count as indefeasible Knowledge. (That is, about
whether it thus counts upon its initial introduction, prior to the
arguments for a non-deceiving God.) Many commentators hold that it
is supposed to count, but the case for this interpretation is by no
means clear.
There is no disputing that Descartes characterizes the cogito
as the “first item of knowledge [cognitione]” (Med. 3, AT 7:35); as
the first “piece of knowledge [cognitio]” (Prin. 1:194, AT 8a:7).
Noteworthy, however, is the Latin terminology (‘cognitio’ and its
cognates) that Descartes uses in these characterizations. As
discussed in Section 1.3, Descartes is a contextualist in the sense
that he uses ‘knowledge’ language in two different contexts of
clear and distinct judgments: the less rigorous context includes
defeasible judgments, as in the case of the atheist geometer (who
can't block hyperbolic doubt); the more rigorous context requires
indefeasible judgments, as with the brand of Knowledge sought after
in the Meditations.
Worthy of attention is that Descartes characterizes the cogito
using the same cognitive language that he uses to characterize the
atheist's defeasible cognition. Recall that Descartes writes of the
atheist's clear and distinct grasp of geometry: “I maintain that
this awareness [cognitionem] of his is not true knowledge
[scientiam]” (Replies 2, AT 7:141). This alone does not prove that
the cogito is supposed to be defeasible. It does, however, prove
that calling it the “first item of knowledge [cognitione]” doesn't
entail that Descartes intends it as indefeasible Knowledge.
Bearing further on whether the cogito counts as indefeasible
Knowledge — prior to having refuted the Evil Genius Doubt — is the
No Atheistic Knowledge Thesis (cf. Section 1.3 above). Descartes
makes repeated and unequivocal statements implying this thesis.
Consider the following texts, each arising in a context of
clarifying the requirements of indefeasible Knowledge (all italics
are mine):
For if I do not know this [i.e., “whether there is a God, and,
if there is, whether he can be a deceiver”], it seems that I can
never be quite certain about anything else. (Med. 3, AT 7:36)
I see that the certainty of all other things depends on this
[knowledge of God], so that without it nothing can ever be
perfectly known [perfecte sciri]. (Med. 5, AT 7:69)
[I]f I did not possess knowledge of God … I should thus never
have true and certain knowledge [scientiam] about anything, but
only shifting and changeable opinions. (Med. 5, AT 7:69)
And upon claiming finally to have achieved indefeasible
Knowledge:
Thus I see plainly that the certainty and truth of all
knowledge [scientiae] depends uniquely on my awareness of the true
God, to such an extent that I was incapable of perfect knowledge
[perfecte scire] about anything else until I became aware of him.
(Med. 5, AT 7:71)
These texts make a powerful case that nothing else can be
indefeasibly Known prior to establishing that we're creatures of an
all-perfect God, rather than an evil genius. These texts make no
exceptions. Descartes looks to hold that hyperbolic doubt is
utterly unbounded — that it undermines all manner of propositions,
including therefore the proposition that “I exist.”
By contrast, other texts seem to support the interpretation
whereby the cogito counts as indefeasible Knowledge. For example,
we have seen texts making clear that it resists hyperbolic doubt.
Often overlooked, however, is that it is only subsequent to the
introduction of the cogito that Descartes has his meditator first
notice the manner in which clear and distinct perception is both
resistant and vulnerable to hyperbolic doubt: the extraordinary
certainty of such perception resists hyperbolic doubt while it is
occurring; it is vulnerable to hyperbolic doubt upon redirecting
one's perceptual attention away from the matter in question. This
theme is developed more fully in the next Section below.
As will emerge, there are two main kinds of interpretive camps
concerning how to deal with the so-called Cartesian Circle. The one
camp contends that hyperbolic doubt is utterly unbounded. On this
view, the No Atheist Knowledge Thesis is taken quite literally. The
other camp contends that hyperbolic doubt is bounded; that is, that
the cogito, and a few other special truths, are in a lockbox of
sorts, utterly protected from even the most hyperbolic doubt. This
view allows that atheists can have indefeasible Knowledge. These
two kinds of interpretations are developed in Section 6.
Further reading: For important passages in Descartes' handling
of the cogito, see the second and third sets of Objections and
Replies. In the secondary literature, see Beyssade (1993),
Broughton (2002), Carriero (2009), Cunning (2007), Hintikka (1962),
Markie (1992) Sarkar (2003), and Vinci (1998).
5. Epistemic Privilege and Defeasibility
The extraordinary certainty and doubt-resistance of the cogito
marks an Archimedean turning point in the meditator's inquiry.
Descartes builds on its impressiveness to help clarify further
epistemic theses. The present Section considers two such theses
about our epistemically privileged perceptions. First, that clarity
and distinctness are, jointly, the mark of our epistemically best
perceptions (notwithstanding that such perception remains
defeasible). Second, that judgments about one's own mind are
epistemically privileged compared with those about bodies.
5.1 Our Epistemic Best: Clear and Distinct Perception and its
Defeasibility
The opening four paragraphs of the Third Meditation are
pivotal. Descartes uses them to codify the phenomenal marks of our
epistemically best perceptions, while clarifying also that even
this impressive epistemic ground falls short of the goal of
indefeasible Knowledge. This sobering realization leads to
Descartes' infamous efforts to refute the Evil Genius Doubt, by
proving a non-deceiving God.
The first and second paragraphs portray the meditator
attempting to build on the success of the cogito by identifying a
general principle of certainty: “I am certain that I am a thinking
thing. Do I not therefore also know what is required for my being
certain about anything?” (AT 7:35). What are the phenomenal marks
of this impressive perception — what is it like to have perception
that good? Descartes' answer: “In this first item of knowledge
[cognitione] there is simply a clear and distinct perception of
what I am asserting” (ibid.).
The third and fourth paragraphs help clarify (among other
things) what Descartes takes to be epistemically impressive about
clear and distinct perception, though absent from external sense
perception. The third paragraph has the meditator observing:
Yet I previously accepted as wholly certain and evident many
things which I afterwards realized were doubtful. What were these?
The earth, sky, stars, and everything else that I apprehended with
the senses. But what was it about them that I perceived clearly?
Just that the ideas, or thoughts, of such things appeared before my
mind. Yet even now I am not denying that these ideas occur within
me. But there was something else which I used to assert, and which
through habitual belief I thought I perceived clearly, although I
did not in fact do so. This was that there were things outside me
which were the sources of my ideas and which resembled them in all
respects. Here was my mistake; or at any rate, if my judgement was
true, it was not thanks to the strength of my perception. (Med. 3,
AT 7:35)
The very next paragraph (the fourth) draws an epistemically
important contrast with external sense perception (as just
characterized). External sense perception does not admit of any
great “strength of perception,” quite unlike clear and distinct
perception. As earlier noted (Section 1.1), the certainty of
interest to Descartes is psychological in character, though not
merely psychological. Not only does occurrent clear and distinct
perception resist doubt, it provides a kind of cognitive
illumination. Both of these epistemic virtues — its
doubt-resistance, and its luminance — are noted in the fourth
paragraph:
[Regarding] those matters which I think I see utterly clearly
with my mind's eye … when I turn to the things themselves which I
think I perceive very clearly, I am so convinced by them that I
spontaneously declare: let whoever can do so deceive me, he will
never bring it about that I am nothing, so long as I continue to
think I am something; or make it true at some future time that I
have never existed, since it is now true that I exist; or bring it
about that two and three added together are more or less than five,
or anything of this kind in which I see a manifest contradiction.
(Med. 3, AT 7:36)
The contrast drawn in the third and fourth paragraphs gets at
a theme that Descartes thinks crucial to his broader project:
namely, that there is “a big difference” — an introspectible
difference — between external sense perception, and perception that
is genuinely clear and distinct. The external senses result in, at
best, “a spontaneous impulse” to believe something, an impulse
we're able to resist. In contrast, occurrent clear and distinct
perception is utterly irresistible: “Whatever is revealed to me by
the natural light — for example that from the fact that I am
doubting it follows that I exist, and so on — cannot in any way be
open to doubt.” (Med. 3, AT 7:38) As Descartes repeatedly conveys:
“my nature is such that so long as I perceive something very
clearly and distinctly I cannot but believe it to be true” (Med. 5,
AT 7:69; cf. 3:64, 7:36, 7:65, 8a:9).
Because of the epistemic impressiveness of clear and distinct
perception (notably, as exhibited in the cogito), the meditator
concludes that such perception will issue as the mark of truth, if
anything will. He tentatively formulates the following candidate
for a criterion of truth: “I now seem [videor] to be able to lay it
down as a general rule that whatever I perceive very clearly and
distinctly is true” (Med. 3, AT 7:35). I shall call this general
principle the ‘C&D Rule’. The announcement of the
candidate criterion is carefully tinged with caution (videor), as
the C&D Rule has yet to be subjected to hyperbolic
doubt. Should it turn out that clarity and distinctness — as an
epistemic ground — is shakable, then, there would remain some doubt
about the general veracity of clear and distinct perception. In
that case, when reflecting back on having perceived something
clearly and distinctly, it would not seem so impressive, after all
— it “would not be enough to make me certain of the truth of the
matter” (ibid.). This cautionary note anticipates the sobering
realization of the fourth paragraph, that, for all its
impressiveness, even clear and distinct perception is in some sense
defeasible.
In what sense defeasible? Recall that the Evil Genius Doubt
is, fundamentally, a doubt about our cognitive natures. Maybe my
mind was made flawed, such that I go wrong even when my perception
is clear and distinct. As the meditator conveys in the fourth
paragraph, my creator might have “given me a nature such that I was
deceived even in matters which seemed most evident,” with the
consequence that “I go wrong even in those matters which I think I
see utterly clearly with my mind's eye” (AT 7:36). The result is a
kind of epistemic schizophrenia:
Moments of epistemic optimism: While I am directly attending
to a proposition — perceiving it clearly and distinctly — I enjoy
an irresistible cognitive luminance and my assent is
compelled.
Moments of epistemic pessimism: When no longer directly
attending — no longer perceiving the proposition clearly and
distinctly — I can entertain the sceptical hypothesis that such
feelings of cognitive luminance are epistemically worthless,
arising from a defective cognitive nature.
The doubt is thus indirect, in the sense that these moments of
epistemic pessimism arise when I am no longer directly attending to
the propositions in question. This indirect operation of hyperbolic
doubt is conveyed not only in the fourth paragraph, but in numerous
other texts, including the following:
Admittedly my nature is such that so long as I perceive
something very clearly and distinctly I cannot but believe it to be
true. But my nature is also such that I cannot fix my mental vision
continually on the same thing, so as to keep perceiving it clearly;
and often the memory of a previously made judgement may come back,
when I am no longer attending to the arguments which led me to make
it. And so other arguments can now occur to me which might easily
undermine my opinion, if I were unaware of [the true] God; and I
should thus never have true and certain knowledge about anything,
but only shifting and changeable opinions. For example, when I
consider the nature of a triangle, it appears most evident to me,
steeped as I am in the principles of geometry, that its three
angles are equal to two right angles; and so long as I attend to
the proof, I cannot but believe this to be true. But as soon as I
turn my mind's eye away from the proof, then in spite of still
remembering that I perceived it very clearly, I can easily fall
into doubt about its truth, if I am unaware of God. For I can
convince myself that I have a natural disposition to go wrong from
time to time in matters which I think I perceive as evidently as
can be. (Med.5, AT 7:69–70; cf. AT 3:64–65; AT 8a:9–10).
Granted, this indirect doubt is exceedingly hyperbolic. Even
so, it means that we lack fully indefeasible Knowledge. Descartes
thus closes the fourth paragraph as follows:
And since I have no cause to think that there is a deceiving
God, and I do not yet even know for sure whether there is a God at
all, any reason for doubt which depends simply on this supposition
is a very slight and, so to speak, metaphysical one. But in order
to remove even this slight reason for doubt, as soon as the
opportunity arises I must examine whether there is a God, and, if
there is, whether he can be a deceiver. For if I do not know this,
it seems that I can never be quite certain about anything else.
(Med. 3, AT 7:36)
The leading role played by the cogito in this four paragraph
passage is easily overlooked. Not only is it (in paragraph two) the
exemplar of judging clearly and distinctly, it is listed (paragraph
four) among the propositions that are compellingly certain while
attended to, though undermined when we no longer thus attend.
What next? How does Descartes think we're to make epistemic
progress if even our epistemic best is subject to hyperbolic doubt?
This juncture of the Third Meditation (the end of the fourth
paragraph) marks the beginning point of Descartes' notorious
efforts to refute the Evil Genius Doubt. His efforts involve an
attempt to establish that we are the creatures not of an evil
genius, but an all-perfect creator who would not allow us to be
deceived about what we clearly and distinctly perceive. Before
turning our attention (in Section 6) to these efforts, let's
digress somewhat to consider a Cartesian doctrine that has received
much attention in its subsequent history.
5.2 The Epistemic Privilege of Judgments About the Mind
Descartes holds that our judgments about our own minds are
epistemically better-off than our judgments about bodies. In our
natural, pre-reflective condition, however, we're apt to confuse
the sensory images of bodies with the external things themselves, a
confusion leading us to think our judgments about bodies are
epistemically impressive. The confusion is clearly expressed
(Descartes would say) in G. E. Moore's famous claim to knowledge —
“Here is a hand” — along with his more general defense of common
sense:
I begin, then, with my list of truisms, every one of which (in
my own opinion) I know, with certainty, to be true. … There exists
at present a living human body, which is my body. This body was
born at a certain time in the past, and has existed continuously
ever since … But the earth had existed also for many years before
my body was born … (1962, 32–33)
In contrast, Descartes writes:
[I]f I judge that the earth exists from the fact that I touch
it or see it, this very fact undoubtedly gives even greater support
for the judgement that my mind exists. For it may perhaps be the
case that I judge that I am touching the earth even though the
earth does not exist at all; but it cannot be that, when I make
this judgement, my mind which is making the judgement does not
exist. (Prin. 1:11, AT 8a:8–9)
Methodical doubt is intended to help us appreciate the folly
of the commonsensical position — helping us to recognize that the
perception of our own minds is “not simply prior to and more
certain … but also more evident” than that of our own bodies (Prin.
1:11, AT 8a:8). “Disagreement on this point,” writes Descartes,
comes from “those who have not done their philosophizing in an
orderly way”; from those who, while properly acknowledging the
“certainty of their own existence,” mistakenly “take ‘themselves’
to mean only their bodies” — failing to “realize that they should
have taken ‘themselves’ in this context to mean their minds alone”
(Prin. 1:12, AT 8a:9).
In epistemological contexts, Descartes underwrites the
mind-better-known-than-body doctrine with methodic doubt. For
example, while reflecting on his epistemic position in regards both
to himself, and to the wax, the Second Meditation meditator
says:
Surely my awareness of my own self is not merely much truer
and more certain than my awareness of the wax, but also much more
distinct and evident. For if I judge that the wax exists from the
fact that I see it, clearly this same fact entails much more
evidently that I myself also exist. It is possible that what I see
is not really the wax; it is possible that I do not even have eyes
with which to see anything. But when I see, or think I see (I am
not here distinguishing the two), it is simply not possible that I
who am now thinking am not something. (Med. 2, AT 7:33)
Other reasons motivate Descartes as well. The doctrine is
closely allied with his commitment to a representational theory of
sense perception. On his view of sense perception, our sense organs
and nerves serve as literal mediating links in the perceptual
chain: they stand between (both spatially and causally) external
things themselves, and the brain events that occasion our
perceptual awareness (cf. Prin. 4:196). In veridical sensation, the
immediate objects of sensory awareness are not external bodies
themselves, nor are we immediately aware of states of our sense
organs or nerves. Rather, the immediate objects of awareness —
whether in veridical sensation, or dreams — are the mind's ideas.
Descartes thinks that the fact of physiological mediation helps
explain delusional ideas, because roughly the same kinds of
physiological processes that produce waking ideas are employed in
producing delusional ideas:
[I]t is the soul which sees, and not the eye; and it does not
see directly, but only by means of the brain. That is why madmen
and those who are asleep often see, or think they see, various
objects which are nevertheless not before their eyes: namely,
certain vapours disturb their brain and arrange those of its parts
normally engaged in vision exactly as they would be if these
objects were present. (Optics, AT 6:141; cf. Med. 6, AT 7:85ff;
Passions 26)
Various passages of the Meditations lay important groundwork
for this theory of perception. For instance, one of the messages of
the wax passage is that sensory awareness does not reach to
external things themselves:
We say that we see the wax itself, if it is there before us,
not that we judge it to be there from its colour or shape; and this
might lead me to conclude without more ado that knowledge of the
wax comes from what the eye sees, and not from the scrutiny of the
mind alone. But then if I look out of the window and see men
crossing the square, as I just happen to have done, I normally say
that I see the men themselves, just as I say that I see the wax.
Yet do I see any more than hats and coats which could conceal
automatons? I judge that they are men. (Med. 2, AT 7:32)
Descartes thinks we're apt to be “tricked by ordinary ways of
talking” (ibid.). In ordinary contexts we don't say that it seems
there are men outside the window; we say we see them. Nor, in such
contexts, are our beliefs about those men apt to result from
conscious, inferentially complex judgments, say, like this one:
“Well, I appear to be awake, and the window pane looks clean, and
there's plenty of light outside, and so on, and I thus conclude
that I am seeing men outside the window.” Even so, our ordinary
ways of speaking and thinking often mislead. Descartes' view is
that the mind's immediate perception does not, strictly speaking,
extend beyond itself, to external bodies. This is an important
basis of the mind-better-known-than-body doctrine. In the
concluding paragraph of the Second Meditation, Descartes
writes:
I see that without any effort I have now finally got back to
where I wanted. I now know that even bodies are not strictly
[proprie] perceived by the senses or the faculty of imagination but
by the intellect alone, and that this perception derives not from
their being touched or seen but from their being understood; and in
view of this I know plainly that I can achieve an easier and more
evident perception of my own mind than of anything else. (Med. 2,
AT 7:34)
Related is a Third Meditation remark. Discussing sense
perception and our ideas of external things, Descartes writes that
the mind's sensation extends strictly and immediately only to the
ideas: “the ideas were, strictly speaking, the only immediate
objects of my sensory awareness [solas proprie et immediate
sentiebam]” (Med. 3, AT 7:75). The theme that ideas are the only
immediate objects of awareness repeats itself elsewhere in
Descartes' writings. As he tells Hobbes: “I make it quite clear in
several places … that I am taking the word ‘idea’ to refer to
whatever is immediately perceived by the mind” (Replies 3, AT
7:181).
Complicating an understanding of such passages is that
Descartes scholarship is divided on whether to attribute to him
some version of an indirect theory of perception, or instead some
version of a direct theory. According to indirect perception
accounts, in normal sensation the mind's perception of bodies is
mediated by an awareness of its ideas of those bodies. By contrast,
direct perception interpretations allow that in normal sensation
the mind's ideas play a mediating role, though this role doesn't
have ideas functioning as items of awareness; rather, the objects
of direct awareness are the external things, themselves. On both
accounts, ideas mediate our perception of external objects. On
direct theory accounts, the mediating role is only a process role.
By analogy, various brain processes mediate our perception of
external objects, but in the normal course of perception we are not
consciously aware of those processes; and likewise for the mind's
ideas, according to direct perception accounts. I hold an indirect
perception interpretation. On the version of the interpretation I
favor — and elsewhere defend (2009) — sensory ideas mediate our
perception of the external bodies they're of, in much the same way
that pictures (or other representational imagery) mediate our
perception of what they portray. More generally, Descartes seems to
view all ideas as mental pictures, of a sort. As he writes: “the
term ‘idea’ is strictly appropriate” only for thoughts that “are as
it were the images of things” (Med. 3, AT 7:37); he adds that “the
ideas in me are like {pictures, or} images” (Med. 3, AT
7:42).
Indirect perception interpretations have figured prominently
in the history of Descartes scholarship. A number of recent
commentators, however, have challenged this traditional view. For
example, John Carriero's recent book on Descartes defends a direct
perception interpretation: “I don't read Descartes as holding that
I am (immediately) aware only of my sensory ideas and only
subsequently (and perhaps indirectly) aware of bodies or their
qualities” (2009, 25). Thus on Carriero's reading, Descartes'
broader argument rebutting our doubts about the external world is
not to be understood as an effort to get on the other side (as it
were) of our ideas:
The argument (as I understand it) is not intended to get us
from a realm of inner mental objects (“sensory ideas”) to some
other realm of outer, physical objects (“bodies”); rather, it is to
confirm our instinctive feeling that we have been receiving
information (“directly”) from outer objects, bodies, all along.
(2009, 26)
Returning to Descartes' views of epistemic privilege, it is
generally overlooked that his mind-better-known-than-body doctrine
is intended as a comparative rather than a superlative thesis. For
Descartes, the only superlative perceptual state is that of clarity
and distinctness: only it is correctly characterized as our
epistemic best. All manner of judgments are susceptible to error
except when based on clear and distinct perception.
This understanding of Descartes deviates from a “Cartesian”
view widely attributed to him, namely: that we simply cannot be
mistaken about the present contents of consciousness; that such
judgments about the mind are, by their very nature, as good as it
gets. (People widely attribute to Descartes a variety of related
doctrines. Compare the doctrines of the infallibility of the mental
— roughly, the doctrine that sincere introspective judgments are
always true; the indubitability of the mental — roughly, that
sincere introspective judgments are indefeasible; and omniscience
with respect to the mental — roughly, that one has Knowledge of
every true proposition about one's own present contents of
consciousness. There is some variation in the way these doctrines
are formulated in the literature.) Am I really denying that this is
Descartes' view? How could we be mistaken about the present
contents of consciousness? And how do I explain the passages in
which Descartes explicitly embraces the thesis?
Descartes' view is that introspective judgments are indeed
privileged, but he regards them as nonetheless subject to error.
Even introspective perception — e.g., our awareness of occurrent
pains and other sensations — must be rendered clear and distinct to
be counted among our epistemic best. Such matters may be clearly
and distinctly perceived, writes Descartes,
…provided we take great care in our judgements concerning them
to include no more than what is strictly contained in our
perception — no more than that of which we have inner awareness.
But this is a very difficult rule to observe, at least with regard
to sensations. (Prin. 1:66, AT 8a:32; cf. Prin. 1:68)
Elsewhere, Descartes writes that we do “frequently make
mistakes, even in our judgements concerning pain” (Prin. 1:67).
These mistakes arise because “people commonly confuse this
perception [of pain] with an obscure judgement they make concerning
the nature of something which they think exists in the painful spot
and which they suppose to resemble the sensation of pain”
(Prin.1:46, AT 8a:22).
But how could I be mistaken in judging, say, that I seem to
see a speckled hen with two speckles? Descartes holds that we can
be mistaken quite simply, by thinking obscurely or confusedly. On
his view, the key to infallibility is not merely that the mind's
attention is on its ideas, but that it renders its ideas clear and
distinct. To help appreciate his view, notice that judgments about
seeming to see hens with two speckles are the same, in kind, as
those about seeming to see hens with two hundred forty-seven
speckles. Quite obviously, I might be confused in this latter case.
(Indeed, it is plausible to hold that only in confusion could I
seem to be seeing exactly that many speckles.) Yet there is no
relevant difference that would explain why the one judgment is
infallible (not merely correct), while the other is fallible. For
Descartes, both are fallible; the relevant consideration
distinguishing their susceptibility to error is that the
two-speckled case is so much easier to render clear and distinct.
But though simpler ideas are generally easier to make clear and
distinct, simplicity is not a requirement: “A concept is not any
more distinct because we include less in it; its distinctness
simply depends on our carefully distinguishing what we do include
in it from everything else” (Prin. 1:63, AT 8a:31; cf. Prin.
1:45).
What about the texts wherein Descartes seems explicitly to
embrace the infallibility of introspective judgments? Consider two
key texts often cited in this connection:
I certainly seem to see, to hear, and to be warmed. This
cannot be false; what is called “having a sensory perception” is
strictly just this, and in this restricted sense of the term it is
simply thinking. (Med. 2, AT 7:29)
Now as far as ideas are concerned, provided they are
considered solely in themselves and I do not refer them to anything
else, they cannot strictly speaking be false; for whether it is a
goat or a chimera that I am imagining, it is just as true that I
imagine the former as the latter. As for the will and the emotions,
here too one need not worry about falsity; for even if the things
which I may desire are wicked or even non-existent, that does not
make it any less true that I desire them. Thus the only remaining
thoughts where I must be on my guard against making a mistake are
judgements. (Med. 3, AT 7:37)
On close inspection, these texts make no claim about the
possibility of introspective judgment error, because these texts —
barring the final sentence of the second passage — are not about
fully formed judgments. Rather, Descartes is isolating the
components of judgment. His two-faculty theory of judgment requires
an interaction between the perceptions of the intellect and the
will's assent (a theory elaborated in the Fourth Meditation). A
sine qua non of judgment error is that there be an act of judgment,
but acts of judgment require both a perception and a volition.
Descartes' claim that mere seemings “cannot strictly speaking be
false” is therefore innocuous: for in isolating the mere seeming,
he isolates the perceptual from the volitional. My merely seeming
to see a speckled hen with two speckles could not, per se, involve
judgment error, because it is not in itself a judgment.
Further reading: On discussions of truth criteria in the 16th
and 17th centuries, see Popkin (1979). On Descartes' theory of
ideas, see Carriero (2009), Chappell (1986), Hoffman (1996), Jolley
(1990), Nadler (2006), Nelson (1997), and Newman (2009). On the
defeasibility of clear and distinct perception (including the
cogito), see Carriero (2009, 339ff), Newman and Nelson (1999). On
contemporary treatments of infallibility, indubitability, and
omniscience, see Alston (1989) and Audi (1993).
6. Cartesian Circle
At the end of Section 5.1 we left off with the fourth
paragraph of the Third Meditation. That passage clarifies that the
Evil Genius Doubt undermines even clear and distinct perception:
upon turning my attention away from matters thus perceived, I can
then wonder whether I have a defective cognitive nature that makes
me go wrong even in such cases. In his Principles treatment of the
same issues, Descartes summarizes the broader problem as
follows:
The mind, then, knowing itself, but still in doubt about all
other things, looks around in all directions in order to extend its
knowledge [cognitionem] further. … Next, it finds certain common
notions from which it constructs various proofs; and, for as long
as it attends to them, it is completely convinced of their truth. …
But it cannot attend to them all the time; and subsequently, when
it happens that it remembers a conclusion without attending to the
sequence which enables it to be demonstrated, recalling that it is
still ignorant as to whether it may have been created with the kind
of nature that makes it go wrong even in matters which appear most
evident, the mind sees that it has just cause to doubt such
conclusions, and that the possession of certain knowledge
[scientiam] will not be possible until it has come to know the
author of its being. (Prin. 1.13, AT 8a:9–10)
How can we overcome this lingering hyperbolic doubt? At the
close of the fourth paragraph of the Third Meditation, Descartes
lays out an ambitious plan: “in order to remove even this slight
reason for doubt, as soon as the opportunity arises I must examine
whether there is a God, and, if there is, whether he can be a
deceiver” (Med. 3, AT 7:36).
The broader argument that unfolds has seemed to many readers
to be viciously circular — the so-called Cartesian Circle.
Descartes first argues from clearly and distinctly perceived
premises to the conclusion that a non-deceiving God exists; he then
argues from the premise that a non-deceiving God exists to the
conclusion that what is clearly and distinctly perceived is true.
The worry is that he presupposes the C&D Rule in
the effort to prove the C&D Rule. In what follows,
I first clarify the key steps in the broader argument for the
divine guarantee of the C&D Rule. I then turn to
the Cartesian Circle.
6.1 Establishing the Divine Guarantee of the
C&D Rule
Descartes' broader argument unfolds in two main steps. The
first main step has him making arguments in the Third Meditation
for the existence of an all-perfect God. From these arguments
Descartes concludes:
I recognize that it would be impossible for me to exist with
the kind of nature I have — that is, having within me the idea of
God — were it not the case that God really existed. By ‘God’ I mean
the very being the idea of whom is within me, that is, the
possessor of all the perfections which I cannot grasp, but can
somehow reach in my thought, who is subject to no defects
whatsoever. It is clear enough from this that he cannot be a
deceiver, since it is manifest by the natural light that all fraud
and deception depend on some defect. (Med. 3, AT 7:51f)
There is much of interest to say about Descartes' arguments
for an all-perfect God. (The Fifth Meditation advances a further
such argument.) In the interests of space, and of focusing on
epistemological concerns, however, these arguments will not be
considered here. (For an overview of Descartes' proofs, see Nolan
and Nelson (2006).)
Descartes' second main step is to argue from the premise (now
established) that an all-perfect God exists, to the general
veracity of the C&D Rule — whereby, whatever is
clearly and distinctly perceived is true. As Descartes tells us:
“In the Fourth Meditation it is proved that everything that we
clearly and distinctly perceive is true” (Synopsis, AT 7:15). It is
this second main step of the broader argument that I want to
develop here.
It is tempting to suppose that this second main step is
unneeded. That is, one might have thought that the
C&D Rule is a straightforward consequence of the
existence of a God who is no deceiver. But this is is too fast. Why
should only the C&D Rule be a straightforward
consequence, but not also a more general infallibility of all our
judgments? Essentially this point is made in the First Meditation,
at the introduction of the Evil Genius Doubt. The meditator
observes that what seems to follow from the standard view — whereby
God “is said to be supremely good,” rather than a deceiver — is
that God would not allow us ever to be mistaken in our
judgments:
But if it were inconsistent with his goodness to have created
me such that I am deceived all the time, it would seem equally
foreign to his goodness to allow me to be deceived even
occasionally; yet this last assertion cannot be made. (Med. 1, AT
7:21)
In short, the “rule for truth” that would seem to be the most
straightforward consequence of an all-perfect creator is this
perfectly general rule: If I form a judgment, then it is true. Yet
quite clearly, this rule for truth doesn't hold. But then, this
fact — the very existence of error — calls into question whether
there is an all-perfect creator. In this First Meditation passage
Descartes is raising the traditional problem of evil, but here
applied to the case of judgment error. As the passage
reasons:
There is judgment error.
Judgment error is incompatible with the hypothesis that I am
the creature of a non-deceiving God.
Therefore, I am not the creature of a non-deceiving God.
These First Meditation remarks set the stage for the
discussion that will come in the Fourth Meditation. Descartes will
need a theodicy for error. (A theodicy is an effort to explain how
God is compatible with evil.) The theodicy needs to show that the
existence of God is compatible with some forms of judgment error,
but not others. The Fourth Meditation thus begins by revisiting the
problem of error. But in context, the meditator has just proven the
existence of an all-perfect God — a scenario generating cognitive
dissonance:
To begin with, I recognize that it is impossible that God
should ever deceive me. … I know by experience that there is in me
a faculty of judgement which, like everything else which is in me,
I certainly received from God. And since God does not wish to
deceive me, he surely did not give me the kind of faculty which
would ever enable me to go wrong while using it correctly.
There would be no further doubt on this issue were it not that
what I have just said appears to imply that I am incapable of ever
going wrong. For if everything that is in me comes from God, and he
did not endow me with a faculty for making mistakes, it appears
that I can never go wrong. (Med. 4, AT 7:53–54)
In an effort to resolve the problem, the meditator begins an
investigation into the causes of error. In the course of the
discussion, Descartes puts forward his theory of judgment. Judgment
arises from the cooperation of the intellect and the will. The
investigation concludes that the cause of error is an improper use
of the will: error arises when the will gives assent to
propositions of which the intellect lacks a clear and distinct
understanding. It is therefore within our power to avoid judgment
error. Error is our fault:
[If] I simply refrain from making a judgement in cases where I
do not perceive the truth with sufficient clarity and distinctness,
then it is clear that I am behaving correctly and avoiding error.
But if in such cases I either affirm or deny, then I am not using
my free will correctly. (Med. 4, AT 7:59–60)
The theodicy that emerges is a version of the freewill
defense. Accordingly, we should thank God for giving us freewill,
but the cost of having freewill is the possibility of misusing it.
Since error is the result of misusing our freewill, we should not
blame God.
Not only is the theodicy used to explain the kinds of error
God can allow, it serves to clarify the kinds of error God cannot
allow. From the latter arises a proof of the C&D
Rule. God can allow errors that are my fault, though not errors
that would be God's fault. When my perception is clear and
distinct, giving assent is not a voluntary option — thus not
explainable by the freewill defense. In such cases, assent is a
necessary consequence of my cognitive nature — a point made in many
passages: “our mind is of such a nature that it cannot help
assenting to what it clearly understands” (AT 3:64); “the nature of
my mind is such that I cannot but assent to these things, at least
so long as I clearly perceive them” (Med. 5, AT 7:65). Since, on
occasions of clarity and distinctness, my assent arises from the
cognitive nature that God gave me, God would be blamable if those
judgments resulted in error. Therefore, they are not in error;
indeed they could not be. That an evil genius might have created me
casts doubt on my clear and distinct judgments. That, instead, an
all-perfect God created me guarantees that these judgments are
true. A clever strategy of argument thus unfolds — effectively
inverting the usual reasoning in the problem of evil:
There is a non-deceiving God.
A non-deceiving God is incompatible with the hypothesis that I
am in error about what I clearly and distinctly perceive.
Therefore, I am not in error about what I clearly and
distinctly perceive.
The first premise was argued in the Third Meditation. The
second premise arises out of the discussion of the Fourth
Meditation. The result is a divine guarantee of the
C&D Rule.
By the end of the Fourth Meditation, important pieces of
Descartes' broader argument are in place. Whether further important
pieces arise in the Fifth Meditation is a matter of interpretive
dispute. In any case, the Fifth Meditation comes to a close with
Descartes asserting that indefeasible Knowledge has finally been
achieved:
I have perceived that God exists, and at the same time I have
understood that everything else depends on him, and that he is no
deceiver; and I have drawn the conclusion that everything which I
clearly and distinctly perceive is of necessity true. … what
objections can now be raised? That the way I am made makes me prone
to frequent error? But I now know that I am incapable of error in
those cases where my understanding is transparently clear. … And
now it is possible for me to achieve full and certain knowledge of
countless matters, both concerning God himself and other things
whose nature is intellectual, and also concerning the whole of that
corporeal nature which is the subject-matter of pure mathematics.
(Med. 5, AT 7:70-71)
6.2 Circularity and the Broader Argument
Students of philosophy can expect to be taught a longstanding
interpretation according to which Descartes' broader argument is
viciously circular. Despite its prima facie plausibility, Descartes
commentators generally resist the vicious circularity
interpretation.
Consider first what every plausible interpretation must
concede: that the two main steps of the broader argument unfold in
a manner suggestive of a circle — I'll indeed refer to them as
‘arcs’. The Third Meditation arguments for God define one
arc:
Arc 1: The conclusion that a non-deceiving God exists is
derived from premises that are clearly and distinctly
perceived.
The Fourth Meditation argument defines a second arc:
Arc 2: The general veracity of propositions that are clearly
and distinctly perceived (i.e., the C&D Rule) is
derived from the conclusion that a non-deceiving God exists.
That the broader argument unfolds in accord with these two
steps is uncontroversial. The question of interest concerns
whether, strictly speaking, these arcs form a circle. The statement
of Arc 1 admits of considerable ambiguity. How one resolves this
ambiguity determines whether vicious circularity is the result.
Let's begin by clarifying what Arc 1 would have to mean to generate
vicious circularity. We'll then consider the main alternative
interpretations of that arc by which commentators avoid a vicious
circle.
Vicious Circularity interpretation:
Arc 1: The conclusion that a non-deceiving God exists is
derived from premises that are clearly and distinctly perceived —
i.e., premises that are accepted because of first accepting the
general veracity of propositions that are clearly and distinctly
perceived.
Arc 2: The general veracity of propositions that are clearly
and distinctly perceived is derived from the conclusion that a
non-deceiving God exists.
Thus rendered, Descartes' broader argument is viciously
circular. The italicized segment of Arc 1 marks an addition to the
original statement of it, thereby clarifying the circularity
reading. Interpreted in this way, Descartes begins his Third
Meditation proofs of God by presupposing the general veracity of
clear and distinct perception. That is, he starts by assuming the
C&D Rule and then uses the rule in the course of
demonstrating it. Evidently, this way of reading Descartes'
argument has pedagogical appeal, for it is ubiquitously taught
(outside of Descartes scholarship) despite the absence of any
textual merit. If there is one point of general agreement in the
secondary literature, it is that the texts do not sustain this
interpretation.
How then should Arc 1 be understood? There are countless
interpretations that avoid vicious circularity, along with numerous
schemes for cataloguing them. For present purposes, I'll catalogue
the various accounts according to two main kinds of non-circular
strategies that commentators attribute to Descartes. (The secondary
literature offers multiple variations of each these main kinds of
interpretations, though I won't here explore the variations.)
Unbounded Doubt interpretations:
Arc 1: The conclusion that a non-deceiving God exists is
derived from premises that are clearly and distinctly perceived —
i.e., premises that are accepted, despite being defeasible, because
our cognitive nature compels us to assent to clearly and distinctly
perceived propositions.
Arc 2: The general veracity of propositions that are clearly
and distinctly perceived is derived from the conclusion that a
non-deceiving God exists.
Again, the italicized segment marks an addition to the
original statement of Arc 1. I call this an ‘Unbounded Doubt’
interpretation, because this kind of interpretation construes
hyperbolic doubt as unbounded. More precisely, the Evil Genius
Doubt is (on this reading) unbounded in the sense that it
undermines all manner of judgments — even the cogito, even the
premises of the Third Meditation proofs of God. It is the
unboundedness of hyperbolic doubt that underwrites the No Atheistic
Knowledge Thesis.
Importantly, if doubt is thus unbounded then there is no
circularity. For, on this reading of it, Arc 1 does not presuppose
the general veracity of the C&D Rule. Hyperbolic
doubt is in play throughout Arc 1.
A question immediately arises for such unbounded doubt
interpretations. Given that hyperbolic doubt is unbounded, why then
are the Arc 1 arguments for God accepted? Why does the meditator
assent to the premises of those arguments, if indeed hyperbolic
doubt undermines them? The answer lies in our earlier discussion of
the indirect manner in which hyperbolic doubt operates (Section
5.1). Recall that while I am clearly and distinctly attending to a
proposition, it compels my assent: “my nature is such that so long
as I perceive something very clearly and distinctly I cannot but
believe it to be true” (Med. 5, AT 7:69; cf. 3:64, 7:36, 7:65,
8a:9). Descartes holds that while we are attending to the steps of
the Third Meditation arguments for God, we have no choice but to
accept those arguments. Of course, from the fact that those
arguments compel our assent while attending to them, it does not
(yet) follow that we have Knowledge of their conclusions. At
present, our focus is on the issue of circularity, not the issue of
how hyperbolic doubt is finally overcome.
The other main kind of interpretation avoids circularity in a
different manner. Let's consider that alternative.
Bounded Doubt interpretations:
Arc 1: The conclusion that a non-deceiving God exists is
derived from premises that are clearly and distinctly perceived —
indeed, premises belonging to a special class of truths immune to
doubt.
Arc 2: The general veracity of propositions that are clearly
and distinctly perceived is derived from the conclusion that a
non-deceiving God exists.
Once again, the italicized segment marks an addition to the
original statement of Arc 1. I call this a ‘Bounded Doubt’
interpretation, because this kind of interpretation construes
hyperbolic doubt as bounded. More precisely, the Evil Genius Doubt
is (on this reading) bounded in the sense that its sceptical
potency does not extend to all judgments: a special class of truths
is outside the bounds of doubt. Exemplary of this special class are
the cogito and, importantly, the premises of the Third Meditation
proofs of God. Propositions in this special class can be
indefeasibly Known even by atheists. Since the truths in this
special class are Knowable independently of a divine guarantee of
the C&D Rule, there is no vicious circularity in
the broader argument. Throughout the arguments of Arcs 1 and 2, the
premises employed count as indefeasibly Known prior to the
Knowledge of the C&D Rule they help
establish.
Proponents of this interpretation are apt to cite Third
Meditation texts referring to truths said to be revealed by the
natural light. The interpretation has it that these natural light
propositions are in no way subject to doubt, unlike ordinary
clearly and distinctly perceivable truths. In order to extend
indefeasible Knowledge to all such truths, it is necessary to
establish the general veracity of the C&D Rule.
Thus, the need (on this interpretation) for Arc 2 in the broader
project.
Though bounded and unbounded doubt interpretations both avoid
vicious circularity, each confronts further difficulties, both
textual and philosophical. Avoiding the charge of vicious
circularity marks the beginning of the interpreter's work, not the
end. Bounded doubt interpreters must explain why, in the first
place, the Evil Genius Doubt's potency does not extend to
propositions in the special class. Unbounded doubt interpreters
must explain why, in the final analysis, the Evil Genius Doubt
eventually loses it undermining potency. Let's consider each of
these further problems.
Granting a bounded doubt interpretation, why — in the first
place — does the Evil Genius Doubt's potency not extend to
propositions in the special class? How is it that the doubt does
undermine the proposition “that two and three added together make
five,” but not the proposition “that there must be at least as much
[reality] in the efficient and total cause as in the effect of that
cause”? The first proposition is included in the list of examples
that are undermined by the Evil Genius Doubt (see fourth paragraph
of Med. 3). The second proposition is a premise in a Third
Meditation argument for God — a proposition immune to doubt,
according to bounded doubt interpretations. What is supposed to be
the relevant difference between these propositions? Given the
indirect manner in which hyperbolic doubt operates, there seems no
clear explanation of why the doubt succeeds in undermining the
first proposition but is somehow resisted by the second. Even more
awkward for this interpretation is that the cogito is included in
the list of examples that that same fourth paragraph passage
implies is vulnerable to doubt.
Granting an unbounded doubt interpretation, why — in the final
analysis — does the Evil Genius Doubt eventually lose its
undermining potency? Putting the point ironically: Why doesn't the
Evil Genius Doubt undermine the very arguments intended to refute
the Evil Genius Doubt, as soon as the mind is no longer attending
to those premises? Consider Descartes' own explanation of how
hyperbolic doubt undermines the conclusions of arguments once their
premises are no longer in the mind's view:
There are other truths which are perceived very clearly by our
intellect so long as we attend to the arguments on which our
knowledge of them depends; and we are therefore incapable of
doubting them during this time. But we may forget the arguments in
question and later remember simply the conclusions which were
deduced from them. The question will now arise as to whether we
possess the same firm and immutable conviction concerning these
conclusions, when we simply recollect that they were previously
deduced from quite evident principles (our ability to call them
‘conclusions’ presupposes such a recollection). (Replies 2, AT
7:146)
So, when we're no longer clearly and distinctly perceiving the
steps of an argument, we do not “possess the same firm and
immutable conviction” of its conclusion. But precisely such moments
are when hyperbolic doubt does its undermining work. This means
that upon diverting attention from the premises of Arcs 1 and 2, it
is then possible to run the Evil Genius Doubt on their conclusions.
It would thus seem that unbounded doubt interpretations leave us in
a Sisyphus-like predicament. According to the myth, each time
Sisyphus pushes his boulder near to the top of the hill, the
boulder somehow slips away, rolling to the very bottom, and the
whole process must start all over. By carefully constructing the
arguments of Arcs 1 and 2, the meditator gains anti-sceptical
momentum, pushing his project near to the goal of Knowledge. But
each time, upon diverting his attention from the premises, he finds
himself back at the bottom of the hill, wondering about the
credibility of those proofs that seemed so evident: “perhaps some
God could have given me a nature such that I was deceived even in
matters which seemed most evident” (Med. 3, AT 7:36).
Again, the hard question for this interpretation: Why, in the
final analysis, does the Evil Genius Doubt eventually lose it
undermining potency? Because I hold an unbounded doubt
interpretation, this is the hard problem I must confront. Elsewhere
(1999), Alan Nelson and I have proposed a solution. Though space
doesn't permit a full recounting of our proposal, I'll try to
summarize the account.
Various themes about innate truths are introduced in the Fifth
Meditation. Among them concerns the effects of repeated meditation:
truths initially noticed only by means of inference might come to
be apprehended self-evidently. In the build-up to the passage
claiming that the Evil Genius Doubt is finally and fully overcome,
Descartes has his meditator say:
But as regards God, if I were not overwhelmed by preconceived
opinions, and if the images of things perceived by the senses did
not besiege my thought on every side, I would certainly acknowledge
him sooner and more easily than anything else. For what is more
self-evident [ex se est apertius] than the fact that the supreme
being exists, or that God, to whose essence alone existence
belongs, exists?
Although it needed close attention for me to perceive this, I
am now just as certain of it as I am of everything else which
appears most certain. And what is more, I see that the certainty of
all other things depends on this, so that without it nothing can
ever be perfectly known. (Med. 5, AT 7:69)
Descartes reiterates this same theme in the Second
Replies:
I ask my readers to spend a great deal of time and effort on
contemplating the nature of the supremely perfect being. Above all
they should reflect on the fact that the ideas of all other natures
contain possible existence, whereas the idea of God contains not
only possible but wholly necessary existence. This alone, without a
formal argument, will make them realize that God exists; and this
will eventually be just as self-evident [per se notum] to them as
the fact that the number two is even or that three is odd, and so
on. For there are certain truths which some people find
self-evident, while others come to understand them only by means of
a formal argument. (Replies 2, AT 7:163 64)
Let's build on these texts. Let's assume that Descartes holds
that the needed conclusion comes to be self-evident — namely, the
conclusion that a non-deceiving God exists who guarantees the
C&D Rule. Indeed, let's assume that this truth
comes to have a kind of cogito-like status, in the following sense:
whenever I try to doubt whether God exists, or is a deceiver, or
the like, the effort at doubt ends up being self-stultifying. When
I try to doubt my own existence, I immediately apprehend that I
must exist in order to be attempting the doubt. Similarly (on this
interpretation), when I try to doubt God's existence, or
benevolence, or the like, I immediately apprehend, as Descartes
writes, that any such sceptical conception of God “implies a
conceptual contradiction — that is, it cannot be conceived” (May
1643 letter, AT 8b:60). In that case, the hard problem for an
unbounded doubt interpretation has dissolved. I can no longer doubt
the Arc 1 conclusions about God, or the Arc 2 conclusions about the
divine guarantee, because those conclusions have become
self-evident. The mechanism for doubting inferential truths — that
of attending to a conclusion without also attending to the premises
on which it rests — is now impotent. No longer resting on premises,
those truths are recognized as true whenever I attend to them. This
interpretation explains why Descartes holds, in the final analysis,
that the Evil Genius Doubt eventually loses it undermining
potency.
Further reading: For Descartes' response to the charges of
circularity: see the Fourth Replies. For texts concerning his final
solution to hyperbolic doubt: see Fifth Meditation; Second Replies;
letter to Regius (24 May 1640). For a treatment of the Fourth
Meditation proof of the C&D Rule, see Newman
(1999). For examples of unbounded doubt interpretations, see
Carriero (2009), Curley (1978 and 1993), DeRose (1992), Loeb
(1992), Newman and Nelson (1999), Sosa (1997a and 1997b), and Van
Cleve (1979). For examples of bounded doubt interpretations, see
Broughton (2002), Doney (1955), Della Rocca (2005), Kenny (1968),
Morris (1973), Rickless (2005), and Wilson (1978). For an anthology
devoted largely to the Cartesian Circle, see Doney (1987).
7. Proving the Existence of the External Material World
The opening line of the Sixth Meditation makes clear its
principal objective: “It remains for me to examine whether material
things exist” (AT 7:71). At this juncture, the meditator Knows of
his own existence and of God's. It follows that there's an external
world with at least one object, God. The existence of an external
material world remains in doubt. Establishing the existence of
bodies is not a straightforward matter of perceiving them, because,
as we have seen, “bodies are not strictly perceived by the senses”
(see Section 5.2 above).
Descartes' strategy for proving an external material world has
two main parts: first, he argues for the externality of the causes
of sensation; second, he argues for the materiality of these
external causes. (I will refer to these putative sensations as
sensations, though, strictly speaking, we cannot yet be using the
term in a way that presupposes being caused by external sense
organs.) From these two steps it follows that there exists an
external material world. Let's consider each phase of the
argument.
7.1 The Case for the Externality of the Causes of
Sensation
Descartes builds on a familiar argument in the history of
philosophy, an argument that appeals to the involuntariness of
sensations. The familiar argument is first articulated in the Third
Meditation. Speaking of his apparently adventitious ideas
(sensations), the meditator remarks:
I know by experience that these ideas do not depend on my
will, and hence that they do not depend simply on me. Frequently I
notice them even when I do not want to: now, for example, I feel
the heat whether I want to or not, and this is why I think that
this sensation or idea of heat comes to me from something other
than myself, namely the heat of the fire by which I am sitting.
(Med. 3, AT 7:38)
The familiar involuntariness argument amounts to the following
— and recall that the me is a thinking thing, a mind:
Sensations come to me involuntarily (I'm unaware of causing
them with my will).
Therefore, sensations are caused by something external to
me.
Therefore, there exists something external to me — an external
world.
(Note: in context, when this argument is first considered by
the meditator, he hasn't yet argued for the existence of God; he
has yet to establish any manner of an external world.)
Though some such involuntariness argument has convinced many
philosophers, the inference from 1 to 2 does not hold up to
methodic doubt, as the meditator explains:
Then again, although these [apparently adventitious] ideas do
not depend on my will, it does not follow that they must come from
things located outside me. Just as the impulses which I was
speaking of a moment ago seem opposed to my will even though they
are within me, so there may be some other faculty [of my mind] not
yet fully known to me, which produces these ideas without any
assistance from external things; this is, after all, just how I
have always thought ideas are produced in me when I am dreaming.
(Med. 3, AT 7:39)
We first looked at this passage in connection with the Always
Dreaming Doubt. Methodic doubt raises the problem of the existence
of external things. For all I Know, my “waking” experiences are
produced not by external things, but by processes similar to those
producing my dreams. This sceptical hypothesis explains why the
familiar involuntariness argument fails: the inference from 1 to 2
presupposes exactly what is at issue — namely, that involuntarily
sensory ideas are produced by external things, rather than by a
subconscious faculty of my mind.
Many philosophers have assumed that we lack the epistemic
resources to solve this sceptical problem. For example, Hume
writes:
By what argument can it be proved, that the perceptions of the
mind must be caused by external objects … and could not arise
either from the energy of the mind itself … or from some other
cause still more unknown to us? It is acknowledged, that, in fact,
many of these perceptions arise not from anything external, as in
dreams, madness, and other diseases. … It is a question of fact,
whether the perceptions of the senses be produced by external
objects … But here experience is, and must be entirely silent.
(Enquiry Sec. 12)
Interestingly, Descartes would agree that experiential
resources cannot solve the problem. By the Sixth Meditation,
however, Descartes purports to have the innate resources he needs
to solve it — notably, innate ideas of mind and body. Among the
metaphysical theses he develops is that mind and body have wholly
distinct essences: the essence of thinking substance is pure
thought; the essence of body is pure extension. In a remarkable
maneuver, Descartes invokes this distinction to refute the
sceptical worry that sensations are produced by a subconscious
faculty of the mind: “nothing can be in me, that is to say, in my
mind, of which I am not aware,” and this “follows from the fact
that the soul is distinct from the body and that its essence is to
think” (1640 letter, AT 3:273). This result allows Descartes to
supplement the involuntariness argument, thereby strengthening the
inference from line 1 to line 2. For from the additional premise
that nothing can be in my mind of which I am unaware, it follows
that if sensations were being produced by some activity in my mind,
then I'd be aware of that activity on the occasion of its
operation. Since I'm not thus aware, it follows that the sensation
I'm having is produced by a cause external to my mind. As Descartes
writes, this cause
cannot be in me, since clearly it presupposes no intellectual
act [of awareness] on my part, and the ideas in question are
produced without my cooperation and often even against my will. So
the only alternative is that it is in another substance distinct
from me … (Med. 6, AT 7:79)
It follows that my sensations are caused by external world
objects. It remains to be shown that these external causes are
material objects.
7.2. The Case for the Materiality of the Causes of
Sensation
On Descartes' analysis, there are three possible options for
the kind of external thing causing sensations:
God
material/corporeal substance
some other created substance
That is, the cause is either infinite substance (God), or
finite substance; and if finite, then either corporeal, or
something else. Descartes eliminates options (a) and (c) by appeal
to God being no deceiver:
But since God is not a deceiver, it is quite clear that he
does not transmit the ideas to me either directly from himself, or
indirectly, via some creature [other than corporeal substance] …
For God has given me no faculty at all for recognizing any such
source for these ideas; on the contrary, he has given me a great
propensity to believe that they are produced by corporeal things.
It follows that corporeal things exist. (Med. 6, AT 7:79–80,
italics added)
This is a highly problematic passage. The “great propensity”
here referred to is not the irresistible compulsion of clear and
distinct perception. (If it were, the conclusion that sensation is
caused by material objects would follow straightaway from this
clear and distinct perception, via the C&D Rule.)
But unless each step of the argument is clearly and distinctly
perceived, Descartes should not be making the argument. Adding to
the difficulties of the passage, he expressly cites the conclusion
as following from the fact that “God is not a deceiver,” implying
that he thinks this inference is supported by a divine guarantee.
What is going on in this passage?
On one kind of interpretation, Descartes relaxes his epistemic
standards in the Sixth Meditation. He no longer insists on
indefeasible Knowledge, now settling for probabilistic arguments.
Though there are no decisive texts indicating that this is
Descartes' intent, the interpretation does find some support. For
instance, in the Synopsis Descartes writes of his Sixth Meditation
arguments:
The great benefit of these arguments is not, in my view, that
they prove what they establish … The point is that in considering
these arguments we come to realize that they are not as solid or as
transparent as the arguments which lead us to knowledge of our own
minds and of God … (AT 7:15–16)
The remark can be read as a concession that the Sixth
Meditation arguments are weaker than the earlier arguments about
minds and God — that these later arguments do not “prove what they
establish.” Of course, one need not read the remark this way. And
other texts are unfavorable to this interpretation. For example, in
the opening paragraphs of the Sixth Meditation Descartes considers
a probabilistic argument for the existence of external bodies.
Though he accepts the proposed account as offering the best
explanation, he nonetheless dismisses it for the express reason
that it grounds “only a probability” — it does not provide the
“basis for a necessary inference that some body exists” (Med. 6, AT
7:73). This is a puzzling dismissal, assuming Descartes has relaxed
his standards to probable inference.
The relaxed standards interpretation falls short for another
reason. It provides no explanation of why Descartes cites a divine
guarantee for the conclusion that sensations are caused by material
objects.
On another kind of interpretation, the troubling passage
appealing to a “great propensity” does not mark a relaxing of
epistemic standards. Instead, Descartes is extending the
implications of his discussion of theodicy in the Fourth
Meditation. I earlier argued (Section 6.1) that Descartes thinks he
demonstrates the divine guarantee of the C&D Rule
by showing that an all-perfect God cannot allow us to be in error
about what we clearly and distinctly perceive. What if Descartes
holds that there are other perceptual circumstances under which an
all-perfect God could not allow us to be in error? And suppose
these other circumstances are cases like those occurring in the
highly problematic passage. Under these assumptions, the resulting
rule for truth would look something like the following:
I am not in error in cases in which (i) I have a great
propensity to believe, and (ii) God provided me no faculty by which
to correct a false such belief.
This rule is more expansive than the C&D Rule,
in that it licenses more kinds of judgments. (Elsewhere (1999), I
have called this the ‘Inclination Without Correction Rule’.)
Clauses (i) and (ii) are tailored to the problematic passage
wherein, as we've seen, Descartes invokes two conditions: “God has
given me no faculty at all for recognizing any such source for
these ideas; on the contrary, he has given me a great propensity to
believe that they are produced by corporeal things.” If indeed
we're on the right interpretive track, then Descartes needs some
way to prove this rule. Assuming a proof similar in structure to
the proof of the C&D Rule, it would run as
follows:
There is a non-deceiving God.
A non-deceiving God cannot allow me to be in error in cases in
which (i) I have a great propensity to believe, and (ii) God
provided me no faculty by which to correct a false such
belief.
Therefore, I am not in error in cases in which (i) I have a
great propensity to believe, and (ii) God provided me no faculty by
which to correct a false such belief.
Assuming Descartes could establish premise 2, he would be
entitled to this more powerful rule, and without having relaxed his
standards of indefeasibility.
Elsewhere (1999), I argue that premise 2 follows from
Descartes's Fourth Meditation discussion. Prima facie, this may
seem ad hoc. But even without detailing the argument, a number of
texts make clear that he holds some version of premise 2. In the
relevant Sixth Meditation passage, Descartes adds that from “the
very fact that God is not a deceiver” there is a “consequent
impossibility of there being any falsity in my opinions which
cannot be corrected by some other faculty supplied by God” (Med. 6,
AT 7:80). In another passage he writes that we would be “doing God
an injustice” if we implied “that God had endowed us with such an
imperfect nature that even the proper use of our powers of
reasoning allowed us to go wrong” (Prin. 4:43, AT 8a:99). In the
Second Replies he addresses the case of judgments that “could not
be corrected by any clearer judgements or by means of any other
natural faculty,” adding: “in such cases I simply assert that it is
impossible for us to be deceived” (Replies 2, AT 7:143f). These
passages strongly suggest that Descartes thinks that God's
benevolent nature entails a more expansive rule of truth than the
C&D Rule. Assuming this interpretation is correct,
the inferential moves in the problematic passage are not ad hoc.
And as will emerge, Descartes looks again to call on this same more
expansive rule in his effort to prove that he is not
dreaming.
A final observation. It is often unnoticed that the conclusion
of Descartes' argument for the existence of an external material
world leaves significant scepticism in place. Granting the success
of the argument, my sensations are caused by an external material
world. But for all the argument shows — for all the broader
argument of the Meditations shows, up to this point — my mind might
be joined to a brain in a vat, rather than a full human body. This
isn't an oversight on Descartes' part. It's all he thinks the
argument can prove. For even at this late stage of the Meditations,
the meditator does not yet Know himself to be awake.
Further reading: For a variation of the Sixth Meditation
argument for the existence of the external material world, see
Descartes' Prin. 2.1. See also Friedman (1997), Garber (1992), and
Newman (1994). On the respects in which the Sixth Meditation
inference draws on Fourth Meditation work, see Newman (1999). For
an interpretation of the Sixth Meditation argument that's
consistent with a direct realist interpretation, see Carriero
(2009, 146ff).
8. Proving that One is Not Dreaming
By design, the constructive arguments of the Meditations
unfold though the meditator remains in doubt about being awake.
This of course reinforces the ongoing theme that Knowledge does not
properly include judgments of external sense. In the closing
paragraph of the Sixth Meditation, Descartes revisits the issue of
dreaming. He claims to show how, in principle — even if not easily
in practice — it is possible to achieve Knowledge that one is
awake.
A casual reading of that final paragraph might suggest that
Descartes offers a naturalistic solution to the problem (viz., a
non-theistic solution), in the form of a continuity test: since
continuity with past experiences holds only of waking but not
dreaming, checking for the requisite continuity is the test for
ascertaining that one is awake. The following remarks can be read
in this way:
I now notice that there is a vast difference between the two
[“being asleep and being awake”], in that dreams are never linked
by memory with all the other actions of life as waking experiences
are. … But when I distinctly see where things come from and where
and when they come to me, and when I can connect my perceptions of
them with the whole of the rest of my life without a break, then I
am quite certain that when I encounter these things I am not asleep
but awake. (Med. 6, AT 7:89–90)
This naturalistic “solution” prompts two obvious criticisms,
both raised by Hobbes in the Third Objections. First, the solution
runs contrary to Descartes' No Atheistic Knowledge Thesis: since
the continuity test (on the naturalistic reading of it) does not
invoke God, it thus appears, as Hobbes notes, “that someone can
know he is awake without knowledge of the true God” (AT 7:196).
Second, as Hobbes adds, it seems one could dream the requisite
continuity: one could “dream that his dream fits in with his ideas
of a long series of past events,” thus undermining the credibility
of the continuity test (AT 7:195).
Mirroring our discussion in Section 7.2, one kind of
interpretation has Descartes relaxing his epistemic standards. He's
aware that the naturalistic solution does not stand up to methodic
doubt, but he's not attempting to overcome the Now Dream Doubt with
indefeasible Knowledge. A problem for this interpretation is that
it doesn't square with the reply Descartes makes to Hobbes' first
objection: “an atheist can infer that he is awake on the basis of
memory of his past life” (via the continuity test); but “he cannot
know that this criterion is sufficient to give him the certainty
that he is not mistaken, if he does not know that he was created by
a non-deceiving God” (Replies 3, AT 7:196). Evidently, Descartes'
solution is not supposed to be available to the atheist. Taken at
face value, this reply rules out a relaxed standards reading; it
indeed rules out any interpretation involving a naturalistic
solution to the problem of dreaming.
On closer inspection, the Sixth Meditation passage puts
forward not a naturalistic solution, but a theistic one. The
meditator finally concludes that he's awake because, as the passage
explicitly reads, “God is not a deceiver” (AT 7:90).
How does his argument go? Recall, in the proof of the external
material world (Section 7.2), that Descartes mysteriously invokes
the following (divinely guaranteed) truth rule:
I am not in error in cases in which (i) I have a great
propensity to believe, and (ii) God provided me no faculty by which
to correct a false such belief.
I suggest that in the dreaming passage Descartes is again
invoking this rule. The passage opens with the meditator observing
the following:
I can almost always make use of more than one sense to
investigate the same thing; and in addition, I can use both my
memory, which connects present experiences with preceding ones, and
my intellect, which has by now examined all the causes of error.
Accordingly, I should not have any further fears about the falsity
of what my senses tell me every day; on the contrary, the
exaggerated doubts of the last few days should be dismissed as
laughable. This applies especially to … my inability to distinguish
between being asleep and being awake. (Med. 6, AT 7:89)
Referring to the worry that he's dreaming as exaggerated
suggests that condition (i) is met — i.e., suggests that the
present circumstance includes a “great propensity” to believe he's
awake. As such, he needs only to establish condition (ii), and
he'll have a divine guarantee of being awake. Notice that an
important theme of the above passage concerns the meditator's
faculties for correcting sensory error — suggesting condition (ii).
I propose that, in context, Descartes' appeal to the continuity
test is best understood in conjunction with condition (ii). As the
meditator says (speaking of his apparently waking
experience):
[W]hen I distinctly see where things come from and where and
when they come to me, and when I can connect my perceptions of them
with the whole of the rest of my life without a break, then I am
quite certain that when I encounter these things I am not asleep
but awake. And I ought not to have even the slightest doubt of
their reality if, after calling upon all the senses as well as my
memory and my intellect in order to check them, I receive no
conflicting reports from any of these sources. For from the fact
that God is not a deceiver it follows that in cases like these I am
completely free from error. (Med. 6, AT 7:90; italics added)
Central to the inference is the meditator's effort to check
the correctness of his belief, by means of his various faculties.
The cases like these to which Descartes refers look to be those
where conditions (i) and (ii) are both satisfied. Recall what
Descartes writes in conjunction with the proof of the external
material world: from “the very fact that God is not a deceiver”
there is a “consequent impossibility of there being any falsity in
my opinions which cannot be corrected by some other faculty
supplied by God” (Med. 6, AT 7:80). On the reading that I am
proposing, Descartes' theistic solution to the Now Dreaming Doubt
employs the same rule that he employs in his proof for the external
material world.
What about Hobbes' second objection — in effect, that one
could dream both (i) and (ii)? Descartes' response: “A dreamer
cannot really connect his dreams with the ideas of past events,
though he may dream that he does. For everyone admits that a man
may be deceived in his sleep.” (AT 7:196) Perhaps Descartes thinks
the situation parallels that of waking life. Those who are
sufficiently tired, or otherwise perceptually inattentive, “cannot
really” perceive truths clearly and distinctly, though it may seem
to them that they do. Whether in waking or dreaming, the Fourth
Meditation theodicy has God allowing us to make judgment errors,
provided that they are correctable. Relevant, therefore, is that
Descartes seems to hold that the mistake of dreaming that we're
awake is correctable: “to be aware that we are dreaming we need
only the intellect” (Replies 5, AT 7:359).
Importantly, Descartes does not say we can easily correct the
mistake of dreaming that we're awake. To the contrary, the Sixth
Meditation treatment of the Now Dreaming Doubt closes with a
concession that his solution is more theoretical than
practical:
But since the pressure of things to be done does not always
allow us to stop and make such a meticulous check, it must be
admitted that in this human life we are often liable to make
mistakes about particular things, and we must acknowledge the
weakness of our nature. (Med. 6, AT 7:90)
Thus the importance of Descartes' First Meditation remark that
“no danger or error will result” from the program of methodic
doubt, “because the task now in hand does not involve action” (Med.
1, AT 7:22). Methodic doubt should not be applied to practical
matters. Prudence dictates that when making practical decisions I
should assume I'm awake, even if I don't Know that I'm awake.
Judgment errors made while mistakenly assuming I'm awake won't have
any actual practical consequences, but those made while mistakenly
assuming I'm dreaming might.
Further reading: See Newman (1999), Williams (1978), and
Wilson (1978).
Bibliography
Primary Sources
Abbreviations Used:
Rules = Rules for the Direction of our Native
Intelligence
Discourse = Discourse on Method
Synopsis = Synopsis of the Meditations
Meditations = Meditations on First Philosophy
Med. = any one of the six Meditations
Objs./Replies = any of the seven sets of objections/replies
that Descartes published along with the Meditations
Prin. = Principles of Philosophy
Passions = The Passions of the Soul
Search = The Search for Truth
AT = Oeuvres de Descartes, Adam, Charles, and Paul Tannery,
(eds.) 1904. Paris: J. Vrin. (References are to volume number and
page.)
CSM = The Philosophical Writings of Descartes, Cottingham,
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Other Internet Resources
Latin text of the Meditations (original version, 1641)
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English translation of the Meditations (by John Veitch,
1901)
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Cogito ergo sum
from New World Encyclopedia
"Cogito, ergo sum" (Latin: "I am thinking, therefore I exist,"
or traditionally "I think, therefore I am") is a philosophical
phrase by René Descartes, and it is a translation of Descartes'
original French statement: "Je pense, donc je suis," which occurs
in his Discourse on Method (1637).
Descartes understood "certainty" as the primary characteristic
of valid knowledge. He conducted a series of thought experiments
(regarding methodic doubt) in order to find the indubitable,
self-evident truth expressed by this phrase. The interpretation of
this phrase has been subject to numerous philosophical debates. The
phrase expresses a skeptical intellectual climate which is
indicative of early modern philosophy.
Although the idea expressed in "cogito ergo sum" is widely
attributed to Descartes, many predecessors offer similar
arguments—particularly Augustine of Hippo in De Civitate Dei (books
XI, 26), who also anticipates modern refutations of the concept.
(In Principles of Philosophy,§7: "Ac proinde haec cognitio, ego
cogito, ergo sum, est omnium prima et certissima etc."). Since
Descartes, the phrase has grown popular beyond the field of
philosophy.
Introduction
The phrase, "cogito ergo sum" is not used in Descartes' most
important work, the Meditations on First Philosophy, but the term
"the cogito" is (often confusingly) referred to in it. Descartes
felt that this phrase, which he had used in his earlier Discourse,
had been misleading in its implication that he was appealing to an
inference, so he changed it to "I am, I exist" (also often called
"the first certainty") in order to avoid the term "cogito."
At the beginning of the second meditation, having reached what
he considers to be the ultimate level of doubt—his argument from
the existence of a deceiving god—Descartes examines his beliefs to
see if any survive the doubt. In his belief in his own existence he
finds that it is impossible to doubt that he exists. Even if there
were a deceptive god (or an evil demon, the tool he uses to stop
himself from sliding back into ungrounded beliefs), his belief in
his own existence would be secure, for how could he be deceived
unless he existed in order to be deceived?
But I have convinced myself that there is absolutely nothing
in the world, no sky, no earth, no minds, no bodies. Does it now
follow that I too do not exist? No: if I convinced myself of
something [or thought anything at all] then I certainly existed.
But there is a deceiver of supreme power and cunning who is
deliberately and constantly deceiving me. In that case I too
undoubtedly exist, if he is deceiving me; and let him deceive me as
much as he can, he will never bring it about that I am nothing so
long as I think that I am something. So, after considering
everything very thoroughly, I must finally conclude that the
proposition, "I am, I exist," is necessarily true whenever it is
put forward by me or conceived in my mind (AT VII 25; CSM II
16–17).
There are two important points that should be noted. First, he
only claims the certainty of his own existence from the
first-person point of view—he has not proved the existence of other
minds at this point. It follows that this is something that has to
be thought through by individuals for themselves as they follow the
course of the meditations. Secondly, he does not assert that his
existence is necessary; he is saying that "if he's thinking," then
he necessarily exists.
Descartes does not use this first certainty, the cogito, as a
foundation upon which to build further knowledge; rather, it is the
firm ground upon which he can stand as he works to restore his
beliefs. As he puts it:
Archimedes used to demand just one firm and immovable point in
order to shift the entire earth; so I too can hope for great things
if I manage to find just one thing, however slight, that is certain
and unshakable (AT VII 24; CSM II 16).
One way of expressing what Descartes meant is, "I am aware of
my existence."
Descartes's argument based on substance-accident
ontology
Descartes' argument depends on and follows necessarily from
his prior acceptance of a substance-accident ontology; that
ontology was derived ultimately from Aristotle and accepted without
serious question by most philosophers in Descartes' time. In
substance-accident ontology, substances exist independently by
themselves—they do not need anything else for their existence—but
accidents can exist only by inhering in a substance.
Consider a man, for example. That man is a substance. But the
man can be sick or healthy, running or sitting, asleep or awake,
thinking or thoughtless, white or brown, and so on. Sickness or
health do not exist independently themselves; they must exist in a
sick or healthy person (or other living thing). Running or sitting
cannot exist by themselves; they can exist only in a running or
sitting man (or other being that runs or sits). It is the same with
being asleep or awake, thinking or thoughtless, or with color.
There is no such thing as “asleepness” or “awakeness” in
themselves; they must exist only in a person or other being—a
substance—that is asleep or awake. There cannot be color (at least
in this ontology) apart from a colored thing (colored
substance).
So, when Descartes concludes—correctly—that his doubt or even
his being deceived is a form of thinking, this leads, since
thinking is an accident and not a substance, to the conclusion that
a thinking substance must exist as a necessary condition or
substrate for the existence of that thinking (or doubting or being
deceived).
Descartes' conclusion "ergo sum" follows from the premise
"cogito" because the existence of thinking, or of one's thinking,
implies the existence of a being ("one") as a necessary locus or
substrate for that thinking.
The substance-accident ontology is, of course, questionable.
David Hume and other phenomenalists usually deny it. But if one
accepts that ontology, then Descartes' statement expresses a
necessary conclusion from it.
Common errors
Some non-philosophers who first come across the cogito attempt
to refute it in the following way. "I think, therefore I exist,"
they argue, can be reversed as "I do not think, therefore I do not
exist." They argue that a rock does not think, but it still exists,
which disproves Descartes' argument. However, this is the logical
fallacy of "denying the antecedent." The correct corollary by modus
tollens is "I do not exist, therefore I do not think."
This fallacy and its prevalence is illustrated by the popular
joke:
Descartes is sitting in a bar, having a drink. The bartender
asks him if he would like another. "I think not," he says, and
vanishes in a puff of logic.
Criticisms of the cogito
There have been a number of criticisms of the cogito. The
first of the two under scrutiny here concerns the nature of the
step from "I am thinking" to "I exist." The contention is that this
is a syllogistic inference, for it appears to require the extra
premise: "Whatever has the property of thinking, exists," and that
extra premise must surely have been rejected at an earlier stage of
the doubt.
It could be argued that "Whatever has the property of
thinking, exists" is self-evident, and thus not subject to the
method of doubt. This is because it is true that any premise of the
form "Whatever has the property F, exists," within the method of
doubt, only the property of thinking is indubitably a property of
the meditator. Descartes does not make use of this defense,
however; he responds to the criticism by conceding that there would
indeed be an extra premise needed, but denying that the cogito is a
syllogism.
Perhaps a more relevant contention is whether the "I" to which
Descartes refers is justified. In Descartes, The Project of Pure
Enquiry, Bernard Williams provides a history and full evaluation of
this issue. The main objection, as presented by Georg Lichtenberg,
is that rather than supposing an entity that is thinking, Descartes
should have just said: "There is some thinking going on." That is,
whatever the force of the cogito, Descartes draws too much from it;
the existence of a thinking thing, the reference of the "I," is
more than the cogito can justify. But that objection is a mistake
if one accepts, as Descartes did, the substance-accident ontology
and its consequences.
Williams provides a meticulous and exhaustive examination of
this objection. He argues, first, that it is impossible to make
sense of "there is thinking" without relativising it to something.
It seems at first as though this something needn't be a thinker,
the "I," but Williams goes through each of the possibilities,
demonstrating that none of them can do the job. He concludes that
Descartes is justified in his formulation (though possibly without
realizing why that was so).
Williams' argument
While the preceding two arguments against the cogito fail,
other arguments have been advanced by Bernard Williams. He claims,
for example, that what one is dealing with when one talks of
thought, or when one says, "I am thinking," is something
conceivable from a third-person perspective; namely objective
"thought-events" in the former case, and an objective thinker in
the latter.
The obvious problem is that, through introspection, or
experience of consciousness, there is no way of moving to conclude
the existence of any third-person fact, verification of which would
require a thought that is necessarily impossible, being, as
Descartes is, bound to the evidence of his own consciousness
alone.
Another way of putting this would be that Descartes' argument
can establish only solipisism. Against that, Descartes could reply
that the problem of solipisism arises in almost any philosophy or
ontology or epistemology, so this objection is not unique to
Descartes's philosophy, and thus it loses at least some of its
supposed force. Moreover, Descartes went on to develop arguments
and evidence that, he thought, does establish the existence of an
external world and other minds.
References
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Boufoy-Bastick, Z. "Introducing 'Applicable Knowledge' as a
Challenge to the Attainment of Absolute Knowledge," Sophia Journal
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Descartes, René. The Philosophical Writings of Descartes.
Cambridge [Cambridgeshire]: Cambridge University Press, 1984. ISBN
0-521-28808-9
Harrison, Simon. Augustine's Way into the Will: The
Theological and Philosophical Significance of De Libero Arbitrio.
Oxford: Oxford University Press, 2006. ISBN 9780198269847
Hatfield, Gary C., and René Descartes. Routledge Philosophy
Guidebook to Descartes and The Meditations. London: Routledge,
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Watson, Richard A. The Downfall of Cartesianism 1673-1712. A
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The Hague: Martinus Nijhoff, 1966.
Williams, Bernard Arthur Owen. Descartes: The Project of Pure
Enquiry. Atlantic Highlands, N.J.: Humanities Press, 1978. ISBN
0391005634
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