Descartes Essay, Research Paper

[All page references and quotations from the Meditations are taken from

the 1995 Everyman edition]

In the Meditations, Descartes embarks upon what Bernard Williams has

called the project of ‘Pure

Enquiry’ to discover certain, indubitable foundations for knowledge. By

subjecting everything to

doubt Descartes hoped to discover whatever was immune to it. In order to

best understand how and

why Descartes builds his epistemological system up from his foundations

in the way that he does, it is

helpful to gain an understanding of the intellectual background of the

17th century that provided the

motivation for his work.

We can discern three distinct influences on Descartes, three conflicting

world-views that fought for

prominence in his day. The first was what remained of the mediaeval

scholastic philosophy, largely

based on Aristotelian science and Christian theology. Descartes had been

taught according to this

outlook during his time at the Jesuit college La Flech? and it had an

important influence on his work,

as we shall see later. The second was the scepticism that had made a

sudden impact on the intellectual

world, mainly as a reaction to the scholastic outlook. This scepticism

was strongly influenced by the

work of the Pyrrhonians as handed down from antiquity by Sextus

Empiricus, which claimed that, as

there is never a reason to believe p that is better than a reason not to

believe p, we should forget about

trying to discover the nature of reality and live by appearance alone.

This attitude was best

exemplified in the work of Michel de Montaigne, who mockingly dismissed

the attempts of

theologians and scientists to understand the nature of God and the

universe respectively. Descartes felt

the force of sceptical arguments and, while not being sceptically

disposed himself, came to believe

that scepticism towards knowledge was the best way to discover what is

certain: by applying sceptical

doubt to all our beliefs, we can discover which of them are indubitable,

and thus form an adequate

foundation for knowledge. The third world-view resulted largely from the

work of the new scientists;

Galileo, Copernicus, Bacon et al. Science had finally begun to assert

itself and shake off its dated

Aristotelian prejudices. Coherent theories about the world and its place

in the universe were being

constructed and many of those who were aware of this work became very

optimistic about the

influence it could have. Descartes was a child of the scientific

revolution, but felt that until sceptical

concerns were dealt with, science would always have to contend with

Montaigne and his cronies,

standing on the sidelines and laughing at science’s pretenses to

knowledge. Descartes’ project, then,

was to use the tools of the sceptic to disprove the sceptical thesis by

discovering certain knowledge

that could subsequently be used as the foundation of a new science, in

which knowledge about the

external world was as certain as knowledge about mathematics. It was

also to hammer the last nail

into the coffin of scholasticism, but also, arguably, to show that God

still had a vital r?le to play in the

discovery of knowledge.

Meditation One describes Descartes’ method of doubt. By its conclusion,

Descartes has seemingly

subjected all of his beliefs to the strongest and most hyberbolic of

doubts. He invokes the nightmarish

notion of an all-powerful, malign demon who could be deceiving him in

the realm of sensory

experience, in his very understanding of matter and even in the simplest

cases of mathematical or

logical truths. The doubts may be obscure, but this is the strength of

the method – the weakness of

criteria for what makes a doubt reasonable means that almost anything

can count as a doubt, and

therefore whatever withstands doubt must be something epistemologically

formidable.

In Meditation Two, Descartes hits upon the indubitable principle he has

been seeking. He exists, at

least when he thinks he exists. The cogito (Descartes’ proof of his own

existence) has been the source

of a great deal of discussion ever since Descartes first formulated it

in the 1637 Discourse on Method,

and, I believe, a great deal of misinterpretation (quite possibly as a

result of Descartes’ repeated

contradictions of his own position in subsequent writings). Many

commentators have fallen prey to

the tempting interpretation of the cogito as either syllogism or

enthymeme. This view holds that

Descartes asserts that he is thinking, that he believes it axiomatic

that ‘whatever thinks must exist’ and

therefore that he logically concludes that he exists. This view, it

seems to me, is wrong. It should be

stated on no occasion, in the Meditations, does Descartes write ‘I am

thinking, therefore I am’, nor

anything directly equivalent. Rather, he says:

“Doubtless, then, that I exist?and, let him deceive me as he may, he can

never bring it about that I

am nothing, so long as I shall be conscious that I am something. So that

it must, in fine, be

maintained, all things being maturely and carefully considered, that

this proposition I am, I exist, is

necessarily true each time it is expressed by me or conceived in my

mind.” (p. 80).

The point here is that it is impossible to doubt the truth of the

proposition ‘I exist’ when one utters it.

It is an indubitable proposition, and one that will necessarily be

presupposed in every attack of the

sceptic. Descartes is not yet entitled to use syllogisms as the

possibility of the malign demon is still

very much alive. As an aside, Descartes himself denies that the cogito

is a syllogism, although it

should be mentioned that in some of the Replies to Objections he seems

to assert that it is in fact a

syllogism. Finally, in the Regulae ad directionem ingenii, Descartes

denies the usefulness of

syllogisms as a means to knowledge.

I believe that, given Descartes’ project, it is fair to grant him that

the cogito deserves the status he

bestows upon it. For can there be anything more certain than something

that is so forceful and so

powerful that every time it is presented to our mind we are forced to

assent to it?

What Descartes did here was to jiggle about the way philosophy normally

approaches the construction

of knowledge structures. By starting with self-knowledge, he elevates

the subjective above the

objective and forces his epistemology to rest upon the knowledge he has

of his own self (and

inadvertently sets the tone for the next 300 years of philosophy). This

leaves him with a problem. He

can know his own existence, that he is a thinking thing and the contents

of his consciousness, but how

can any of this ever lead to any knowledge of anything outside of

himself?

The answer is that, by itself, it can’t. Descartes, in the third

Meditation, attempts to prove the

existence of God, defined as a being with all perfections. This proof is

to be derived from his idea of a

God, defined as a being with all perfections. So far, so good -

Descartes examines the contents of his

consciousness and discovers within it this idea, and we can allow him

this. At this point, however, he

introduces a whole series of scholastic principles concerning different

modes of causation and reality

without proper justification:

“For, without doubt, those [ideas considered as images, as opposed to

modes of consciousness] that

represent substances are something more, and contain in themselves, so

to speak, more objective

reality, that is, participate by representation in higher degrees of

being or perfection than those that

represent only modes or accidents; and again the idea by which I

conceive a God?has certainly in it

more objective reality than those ideas by which finite substances are

represented.

Now it is manifest by the natural light that there must be at least

as much reality in the efficient

and total cause as in its effect; for whence can the effect draw its

reality if not from its cause? And

how could the cause communicate to it this reality unless it possessed

it in itself?”

Whence do these principles draw their indubitability? Even if we grant

that it is contrary to natural

reason that an effect can have greater ‘reality’ than its cause, that

the concepts of modes and

substances are coherent with Descartes’ method, let alone possess the

properties that he ascribes to

them, then surely we can still bring the malign demon into play? Is it

not possible that this all-

powerful demon could bring it about that Descartes has a notion of a

being with all possible

perfections that he calls God? No, says Descartes, because the notion

(representing something perfect)

would then have more objective reality than the demon (as something evil

and thus imperfect) has

formal reality, and ‘it is manifest by the natural light’ that this is

not possible. But why not? Maybe the

demon has just made it seem impossible, and it seems that Descartes has

no answer to this.

Further problems remain. Cosmological arguments for God invoking the

notion of causation have

always had to contend with the problem of the cause of God. For if all

events (or ideas) are caused

ultimately by God, then what about God Himself? Why should He be exempt

from this rule? The

standard response to this is to claim that God, being omnipotent, causes

Himself. One of the chief

perfections that Descartes attributes to God is that of

’self-existence’, that is, that His existence

depends on nothing else but itself. But if we examine this idea, it

seems a little confused. If God is the

efficient cause of God then we are forced to ask how something that does

not yet exist can cause

anything. If God is the formal cause of God, i.e. it is part of the

intrinsic nature of God that he exists –

which seems more likely – then it seems that we have merely a

reformulation of the ontological

argument for God’s existence from Meditation 5.

It seems that Descartes may have anticipated the wealth of criticism

that the causal proof of God

would inspire, and so, after explaining how human error and a

benevolent, non-deceiving God are

compatible in Meditation Four, he produced in Meditation Five a version

of the mediaeval

ontological argument for God’s existence. Unlike the causal argument,

the ontological argument

doesn’t involve the covert import of any new principles. It simply

purports to show that, from an

analysis of his own idea of God, Descartes can show that He necessarily

exists. The reasoning goes

like this:

I have ideas of things which have true and immutable natures.

If I perceive clearly and distinctly that a property belongs to an

idea’s true and immutable nature, then

it does actually belong to that nature.

I perceive clearly and distinctly that God’s true and immutable nature

is that of a being with all

perfections.

Further, I perceive clearly and distinctly that existence is a

perfection and non-existence a non-

perfection.

Thus existence belongs to God’s true and immutable nature.

God exists.

One of the interesting things about this argument is that, at first

sight, it does not seem to depend in

any way upon anything that has been proved hitherto. It is an

application of pure logic, an analysis of

what we mean when we say ‘God’ and a inference from that analysis.

Descartes explicitly says that an

idea’s true and immutable nature does not in any way depend upon his

thinking it, and thus upon his

existence. Once he has perceived clearly and distinctly that an idea’s

true and immutable nature

consists in such-and-such, that is the case whether or not he thinks it

is, or even if he exists or not.

Descartes in fact recognises the primacy of the ontological argument:

“although all the conclusions of

the preceding Meditations were false, the existence of God would pass

with me for a truth at least as

certain as I ever judged any truth of mathematics to be.” If this is

true, which it seems to be, then this

argument is only as trustworthy as the faculties which enabled us to

construct it, which are the same

faculties that enable us to know mathematical truths, and so it seems

worthwhile to ask how, under

Descartes’ theory, we come to know mathematical truths. Descartes claims

we perceive them clearly

and distinctly. How do we know that what we perceive clearly and

distinctly is true? Because God,

being perfect, is no deceiver, and would not let it be the case that we

could ever perceive something

clearly and distinctly without it being the case. It seems then, that

this proof of God, relying on the

veracity of clear and distinct ideas, relies on the certain knowledge

that a non-deceiving God exists.

We have another proof of God, the causal proof as described in

Meditation three. But apart from the

patent futility of using one proof of p to construct another proof of p,

on examining the causal proof of

God further, we find that it, too, relies upon a methodology that can

only be relied upon if the divine

guarantee is present, for if this guarantee is not present, then, as I

mentioned above, how can we be

sure that the all-powerful demon is not exercising his malignant

influence?

This, of course, is the infamous Cartesian circle, first identified by

Arnauld in the Fourth Objections

and discussed ever since. Many philosophers have tried to get Descartes

off the hook in various ways,

some by denying that there is a circle and some by admitting the

circularity but denying its

significance. I will here briefly evaluate a few of their arguments.

Some commentators have taken a passage from Descartes’ reply to the

Second set of Objections

(Mersenne’s) to indicate that Descartes is only actually interested in

the psychological significance of

fundamental truths. The passage is as follows:

“If a conviction is so firm that 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 we could

reasonably want.”

Under my interpretation, this is what it is about the cogito that makes

it so important for Descartes,

so we cannot have any argument with the principle expressed by him in

the above passage. But can it

help break the circle? When we clearly and distinctly perceive

something, Descartes says, fairly I

think, that this perception compels our assent, that we cannot but

believe it. God’s r?le in the system,

to these commentators, is as a guarantor of our memory regarding clarity

and distinctness. In other

words, once we have proved God’s existence, we can happily know that any

memory we have of a

clear and distinct idea regarding x is true i.e. that we really did have

a clear and distinct idea of x. But

this does not seem satisfactory, as we still do not have a divine

guarantee for the reasoning that leads

us from the clear and distinct notions we originally have about God to

the proof of His existence. We

can give assent to the clear and distinct notions we have originally; in

fact, we are compelled to give

this assent when the notions are presented to our mind, but the logical

steps we take from these ideas

to the final proof is still subject to the evil demon because God is not

yet proven. Furthermore, because

these steps are needed, the memory of the original clear and distinct

ideas are themselves subject to

doubt because God is not yet proven. It seems that the only way either

of the proofs of God could be

accepted would be if we had an original clear and distinct perception of

God directly presented to our

mind (qualitatively similar to the cogito). But this in itself would

make any future proofs redundant.

Interestingly, this sounds quite similar to a divine revelation.

Harry Frankfurt, in his book ‘Demons, Dreamers and Madmen’, has argued

that what Descartes is

actually looking for is a coherent, indubitable set of beliefs about the

universe. Whether they are ‘true’

or not is irrelevant. Perfect certainty is totally compatible with

absolute falsity. Our certainty may not

coincide precisely with ‘God’s’ truth, but should this matter?:

“Reason?can give us certainty. It can serve to establish beliefs in

which there is no risk of betrayal.

This certainty is all we need and all we demand. Perhaps our certainties

do not coincide with God’s

truth?But this divine or absolute truth, since it is outside the range

of our faculties and cannot

undermine our certainties, need be of no concern to us.” (Frankfurt, p

184)

This is almost a Kantian approach to knowledge, where we as humans only

concern ourselves with

the phenomena of objects as they present themselves to us, not with the

objects in themselves. Can we

ascribe this view to Descartes? It’s tempting, given what we have said

above regarding the prime

importance of indubitability, but it would seem that a God presenting

ideas to us in a form which

doesn’t correspond to reality, and then giving us a strong disposition

to believe that they do

correspond to reality would be a deceiving God and contrary to

Descartes’ notion of Him. Thus the

belief set would not be coherent. Perhaps, as we do not have clear and

distinct ideas of the bodies we

perceive, and as the divine guarantee only extends as far as clear and

distinct ideas, we are being too

hasty in judging that reality is how it appears to be and if we stopped

to meditate further we would see

that reality is actually like something else. But aside from the fact

that this seems unlikely, Descartes

never seemed to envisage the possibility.

So much for the Cartesian circle. Where does this leave the ontological

argument, which we had only

just begun to discuss? Aside from the methodological difficulties, there

do seem to two further

problems with it. The first has been noted by almost every student of

Descartes over the years – that of

the description of existence as a property. Put briefly, this objection

states that existence is not a

property like ‘red’ or ‘hairy’ or ‘three-sided’ that can be applied to a

subject, and thus it makes no sense

to say that existence is part of something’s essence. If we assert that

x is y, we are already asserting the

existence of x as soon as we mention it, prior to any application of a

predicate. from the beginning. In

other words, to say ‘x exists’ is to utter a tautology and to say that

‘x doesn’t exist’ is to contradict

oneself. So how can sentences of the form ‘x doesn’t exist’ make sense?

one may well ask. It is because

these sentences are shorthand for ‘the idea I have of x has no

corresponding reality’ and it was to

solve problems like this that Bertrand Russell constructed his theory of

descriptions. To add existence

to an idea doesn’t just make it an idea with a new property, it changes

it from an idea into an existent

entity.

Finally, if Descartes is right, there seems no reason why we cannot

construct any other idea whose

essence includes existence. For instance, if I conjure up the idea of

‘an existent purple building that

resembles the Taj Mahal’, then it is the true and immutable nature of

this idea that it is a building,

that this building resembles the Taj Mahal, that the building is

purple, and that it exists. But no such

building does exist, as far as I am aware, and if it did exist, its

existence would not be necessary, but

contingent. This in itself is enough, I think, to show that the

ontological argument is false.

Once we have destroyed Descartes’ proofs of the existence of God, the

edifice of knowledge

necessarily comes tumbling down with them, as we find that almost

everything Descartes believes in

is dependent on God’s nature as a non-deceiver:

“I remark?that the certitude of all other truths is so absolutely

dependent on it, that without this

knowledge it is impossible ever to know anything perfectly.” (p.115)

The only possible exceptions are those assent-compelling beliefs such

as the cogito. Even these,

however, are doubtful when we are not thinking about them, and the above

passage does give weight

to Edwin Curley’s argument that:

“Descartes would hold that the proposition “I exist” is fully certain

only if the rest of the argument of

the Meditations goes through. We must buy all or nothing.”

This is not the end of the story, though. As far as Descartes is

concerned, by the end of Meditation

Five, he has produced two powerful proofs of God, has a clear and

distinct notion of his own self, has

a criterion for truth, knows how to avoid error and is beginning to form

ideas regarding our

knowledge of corporeal bodies.. And so it remains only to explain why we

are fully justified in

believing in corporeal bodies, and also to draw the ideas of Meditation

Two regarding self-knowledge

to their full conclusion.

Regarding the nature of corporeal bodies and our knowledge of them, it

seems to me that, given his

premises, the conclusions Descartes draws in Meditation Six are

generally the correct ones. He again

invokes the causal to argue that the ideas of bodies we have within our

minds must be caused by

something with at least as much formal reality as the ideas have

objective reality. We could

theoretically be producing these ideas, but Descartes dismisses this

possibility for two reasons – firstly,

that the idea of corporeality does not presuppose thought and secondly

that our will seems to have no

effect on what we perceive or don’t perceive. (This second argument

seems to me to ignore dreaming,

in which what we perceive derives from us but is independent of our

will). The ideas, then, could

come from God, or from another being superior to us but inferior to God.

But this, too, is impossible,

argues Descartes, as if it were the case that God produces the ideas of

bodies in us, then the very

strong inclination we have towards believing that the idea-producing

bodies resemble the ideas we

have would be false and thus God would be allowing us to be deceived

which is not permissible. The

same would apply if any other being were producing these ideas. Thus,

concludes Descartes, it is most

likely that our ideas of corporeal bodies are actually caused by bodies

resembling those ideas. We

cannot be certain, however, as we cannot claim to have clear and

distinct notions of everything we

perceive. We can, however, claim certainty with regard to those

properties of bodies which we do

know with clarity and distinction; namely, size, figure (shape),

position, motion, substance, duration

and number (not all of these assertions are justified). Obviously we

cannot claim that we know these

properties for specific bodies with clarity and distinction, for to do

so would leave open the question of

why it is that astronomy and the senses attribute different sizes to

stars. What Descartes means is that

we can be sure that these primary qualities exist in bodies in the same

way that they do in our ideas of

bodies. This cannot be claimed for qualities such as heat, colour, taste

and smell, of which our ideas

are so confused and vague that we must always reserve judgement. (This

conclusion is actually quite

similar to the one John Locke drew fifty years later in his Essay

Concerning Human Understanding.)

I think we can grant this reasoning, with the caveat regarding dreaming

that I noted above, and of

course the other unproved reasonings that Descartes exhumes here, such

as the causal principle.

Furthermore, it seems to be further proof that Descartes does believe we

can get to know objects in

themselves to a certain extent.

Finally, I turn to Descartes’ argument for the distinction of mind and

body. Descartes believes he has

shown the mind to be better known than the body in Meditation Two. In

Meditation Six he goes on to

claim that, as he knows his mind and knows clearly and distinctly that

its essence consists purely of

thought, and that bodies’ essences consist purely of extension, that he

can conceive of his mind and

body as existing separately. By the power of God, anything that can be

clearly and distinctly conceived

of as existing separately from something else can be created as existing

separately. At this point,

Descartes makes the apparent logical leap to claiming that the mind and

body have been created

separately, without justification. Most commentators agree that this is

not justified, and further, that

just because I can conceive of my mind existing independently of my body

it does not necessarily

follow that it does so. In defence of Descartes, Saul Kripke has

suggested that Descartes may have

anticipated a modern strand of modal logic that holds that if x=y, then

L (x=y). In other words, if x is

identical to y then it is necessarily identical to it. From this it

follows that if it is logically possible that

x and y have different properties then they are distinct. In this

instance, that means that because I can

clearly and distinctly conceive of my mind and body as existing

separately, then they are distinct. The

argument, like much modern work on identity, is too technical and

involved to explore here in much

depth. But suffice to say that we can clearly and distinctly conceive of

Dr Jekyll and Mr. Hyde as

being distinct and yet they are identical, necessarily so under Kripke’s

theory. It is doubtful that

Kripke can come to Descartes’ aid here and Descartes needs further

argument to prove that the mind

and the body are distinct.

And so we finish our discussion of Descartes’ attempts to extricate

himself from the sceptical doubts

he has set up for himself. As mentioned previously, the ultimate

conclusion to draw regarding the

success of the enterprise that Descartes set for himself must be that he

failed. When the whole

epistemological structure is so heavily dependent on one piece of

knowledge – in this case the

knowledge that God exists – then a denial of that knowledge destroys the

whole structure. All that we

can really grant Descartes – and this is certainly contentious – is that

he can rightly claim that when a

clear and distinct idea presents itself to his mind, he cannot but give

his assent to this idea, and

furthermore, that while this assent is being granted, the clear and

distinct idea can be justly used as a

foundation for knowledge. The most this gets us – and this is not a

little – is the knowledge of our own

existence each time we assert it. But Descartes’ project should not be

judged by us as a failure – the

fact that he addressed topics of great and lasting interest, and

provided us with a method we can both

understand and utilise fruitfully, speaks for itself.

Bibliography

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Philosophy

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Descartes, Ren? The Philosophical Writings of Descartes volume I and II

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Cottingham, R. Stoothoff and D. Murdoch. Cambridge, 1985.

Frankfurt, Harry Demons, Dreamers and Madmen. Bobbs-Merrill, 1970.

Curley, Edwin Descartes Against the Skeptics. Oxford, 1978.

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Sorrell, Tom Descartes: Reason and Experience. Open University Press,

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