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How Does Descartes Try To Extricate Himself From The Sceptical Doubts That He Has Raised? Does He Succeed? Essay, Research Paper
[All page references and quotations from the Meditations are taken fromthe 1995 Everyman edition]
In the Meditations, Descartes embarks upon what Bernard Williams hascalled the project of ‘PureEnquiry’ to discover certain, indubitable foundations for knowledge. Bysubjecting everything todoubt Descartes hoped to discover whatever was immune to it. In order tobest understand how andwhy Descartes builds his epistemological system up from his foundationsin the way that he does, it ishelpful to gain an understanding of the intellectual background of the17th century that provided themotivation for his work.
We can discern three distinct influences on Descartes, three conflictingworld-views that fought forprominence in his day. The first was what remained of the mediaevalscholastic philosophy, largelybased on Aristotelian science and Christian theology. Descartes had beentaught according to thisoutlook during his time at the Jesuit college La Flech? and it had animportant influence on his work,as we shall see later. The second was the scepticism that had made asudden impact on the intellectualworld, mainly as a reaction to the scholastic outlook. This scepticismwas strongly influenced by thework of the Pyrrhonians as handed down from antiquity by SextusEmpiricus, which claimed that, asthere is never a reason to believe p that is better than a reason not tobelieve p, we should forget abouttrying to discover the nature of reality and live by appearance alone.This attitude was bestexemplified in the work of Michel de Montaigne, who mockingly dismissedthe attempts oftheologians and scientists to understand the nature of God and theuniverse respectively. Descartes feltthe force of sceptical arguments and, while not being scepticallydisposed himself, came to believethat scepticism towards knowledge was the best way to discover what iscertain: by applying scepticaldoubt to all our beliefs, we can discover which of them are indubitable,and thus form an adequatefoundation for knowledge. The third world-view resulted largely from thework of the new scientists;Galileo, Copernicus, Bacon et al. Science had finally begun to assertitself and shake off its datedAristotelian prejudices. Coherent theories about the world and its placein the universe were beingconstructed and many of those who were aware of this work became veryoptimistic about theinfluence it could have. Descartes was a child of the scientificrevolution, but felt that until scepticalconcerns were dealt with, science would always have to contend withMontaigne and his cronies,standing on the sidelines and laughing at science’s pretenses toknowledge. Descartes’ project, then,was to use the tools of the sceptic to disprove the sceptical thesis bydiscovering certain knowledgethat could subsequently be used as the foundation of a new science, inwhich knowledge about theexternal world was as certain as knowledge about mathematics. It wasalso to hammer the last nailinto the coffin of scholasticism, but also, arguably, to show that Godstill had a vital r?le to play in thediscovery of knowledge.
Meditation One describes Descartes’ method of doubt. By its conclusion,Descartes has seeminglysubjected all of his beliefs to the strongest and most hyberbolic ofdoubts. He invokes the nightmarishnotion of an all-powerful, malign demon who could be deceiving him inthe realm of sensoryexperience, in his very understanding of matter and even in the simplestcases of mathematical orlogical truths. The doubts may be obscure, but this is the strength ofthe method – the weakness ofcriteria for what makes a doubt reasonable means that almost anythingcan count as a doubt, andtherefore whatever withstands doubt must be something epistemologicallyformidable.
In Meditation Two, Descartes hits upon the indubitable principle he hasbeen seeking. He exists, atleast when he thinks he exists. The cogito (Descartes’ proof of his ownexistence) has been the sourceof a great deal of discussion ever since Descartes first formulated itin the 1637 Discourse on Method,and, I believe, a great deal of misinterpretation (quite possibly as aresult of Descartes’ repeatedcontradictions of his own position in subsequent writings). Manycommentators have fallen prey tothe tempting interpretation of the cogito as either syllogism orenthymeme. This view holds thatDescartes asserts that he is thinking, that he believes it axiomaticthat ‘whatever thinks must exist’ andtherefore that he logically concludes that he exists. This view, itseems to me, is wrong. It should bestated on no occasion, in the Meditations, does Descartes write ‘I amthinking, therefore I am’, noranything directly equivalent. Rather, he says:
“Doubtless, then, that I exist?and, let him deceive me as he may, he cannever bring it about that Iam nothing, so long as I shall be conscious that I am something. So thatit must, in fine, bemaintained, all things being maturely and carefully considered, thatthis proposition I am, I exist, isnecessarily true each time it is expressed by me or conceived in mymind.” (p. 80).
The point here is that it is impossible to doubt the truth of theproposition ‘I exist’ when one utters it.It is an indubitable proposition, and one that will necessarily bepresupposed in every attack of thesceptic. Descartes is not yet entitled to use syllogisms as thepossibility of the malign demon is stillvery much alive. As an aside, Descartes himself denies that the cogitois a syllogism, although itshould be mentioned that in some of the Replies to Objections he seemsto assert that it is in fact asyllogism. Finally, in the Regulae ad directionem ingenii, Descartesdenies the usefulness ofsyllogisms as a means to knowledge.
I believe that, given Descartes’ project, it is fair to grant him thatthe cogito deserves the status hebestows upon it. For can there be anything more certain than somethingthat is so forceful and sopowerful that every time it is presented to our mind we are forced toassent to it?
What Descartes did here was to jiggle about the way philosophy normallyapproaches the constructionof knowledge structures. By starting with self-knowledge, he elevatesthe subjective above theobjective and forces his epistemology to rest upon the knowledge he hasof his own self (andinadvertently sets the tone for the next 300 years of philosophy). Thisleaves him with a problem. Hecan know his own existence, that he is a thinking thing and the contentsof his consciousness, but howcan any of this ever lead to any knowledge of anything outside ofhimself?
The answer is that, by itself, it can’t. Descartes, in the thirdMeditation, attempts to prove theexistence of God, defined as a being with all perfections. This proof isto be derived from his idea of aGod, defined as a being with all perfections. So far, so good -Descartes examines the contents of hisconsciousness and discovers within it this idea, and we can allow himthis. At this point, however, heintroduces a whole series of scholastic principles concerning differentmodes of causation and realitywithout proper justification:
“For, without doubt, those [ideas considered as images, as opposed tomodes of consciousness] thatrepresent substances are something more, and contain in themselves, soto speak, more objectivereality, that is, participate by representation in higher degrees ofbeing or perfection than those thatrepresent only modes or accidents; and again the idea by which Iconceive a God?has certainly in itmore objective reality than those ideas by which finite substances arerepresented.Now it is manifest by the natural light that there must be at leastas much reality in the efficientand total cause as in its effect; for whence can the effect draw itsreality if not from its cause? Andhow could the cause communicate to it this reality unless it possessedit in itself?”
Whence do these principles draw their indubitability? Even if we grantthat it is contrary to naturalreason that an effect can have greater ‘reality’ than its cause, thatthe concepts of modes andsubstances are coherent with Descartes’ method, let alone possess theproperties that he ascribes tothem, then surely we can still bring the malign demon into play? Is itnot possible that this all-powerful demon could bring it about that Descartes has a notion of abeing with all possibleperfections that he calls God? No, says Descartes, because the notion(representing something perfect)would then have more objective reality than the demon (as something eviland thus imperfect) hasformal reality, and ‘it is manifest by the natural light’ that this isnot possible. But why not? Maybe thedemon has just made it seem impossible, and it seems that Descartes hasno answer to this.
Further problems remain. Cosmological arguments for God invoking thenotion of causation havealways had to contend with the problem of the cause of God. For if allevents (or ideas) are causedultimately by God, then what about God Himself? Why should He be exemptfrom this rule? Thestandard response to this is to claim that God, being omnipotent, causesHimself. One of the chiefperfections that Descartes attributes to God is that of’self-existence’, that is, that His existencedepends on nothing else but itself. But if we examine this idea, itseems a little confused. If God is theefficient cause of God then we are forced to ask how something that doesnot yet exist can causeanything. If God is the formal cause of God, i.e. it is part of theintrinsic nature of God that he exists -which seems more likely – then it seems that we have merely areformulation of the ontologicalargument for God’s existence from Meditation 5.
It seems that Descartes may have anticipated the wealth of criticismthat the causal proof of Godwould inspire, and so, after explaining how human error and abenevolent, non-deceiving God arecompatible in Meditation Four, he produced in Meditation Five a versionof the mediaevalontological argument for God’s existence. Unlike the causal argument,the ontological argumentdoesn’t involve the covert import of any new principles. It simplypurports to show that, from ananalysis of his own idea of God, Descartes can show that He necessarilyexists. The reasoning goeslike this:
I have ideas of things which have true and immutable natures.If I perceive clearly and distinctly that a property belongs to anidea’s true and immutable nature, thenit does actually belong to that nature.I perceive clearly and distinctly that God’s true and immutable natureis that of a being with allperfections.Further, I perceive clearly and distinctly that existence is aperfection 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 firstsight, it does not seem to depend inany way upon anything that has been proved hitherto. It is anapplication of pure logic, an analysis ofwhat we mean when we say ‘God’ and a inference from that analysis.Descartes explicitly says that anidea’s true and immutable nature does not in any way depend upon histhinking it, and thus upon hisexistence. Once he has perceived clearly and distinctly that an idea’strue and immutable natureconsists in such-and-such, that is the case whether or not he thinks itis, or even if he exists or not.Descartes in fact recognises the primacy of the ontological argument:”although all the conclusions ofthe preceding Meditations were false, the existence of God would passwith me for a truth at least ascertain as I ever judged any truth of mathematics to be.” If this istrue, which it seems to be, then thisargument is only as trustworthy as the faculties which enabled us toconstruct it, which are the samefaculties that enable us to know mathematical truths, and so it seemsworthwhile to ask how, underDescartes’ theory, we come to know mathematical truths. Descartes claimswe perceive them clearlyand distinctly. How do we know that what we perceive clearly anddistinctly is true? Because God,being perfect, is no deceiver, and would not let it be the case that wecould ever perceive somethingclearly and distinctly without it being the case. It seems then, thatthis proof of God, relying on theveracity of clear and distinct ideas, relies on the certain knowledgethat a non-deceiving God exists.We have another proof of God, the causal proof as described inMeditation three. But apart from thepatent futility of using one proof of p to construct another proof of p,on examining the causal proof ofGod further, we find that it, too, relies upon a methodology that canonly be relied upon if the divineguarantee is present, for if this guarantee is not present, then, as Imentioned above, how can we besure that the all-powerful demon is not exercising his malignantinfluence?
This, of course, is the infamous Cartesian circle, first identified byArnauld in the Fourth Objectionsand discussed ever since. Many philosophers have tried to get Descartesoff the hook in various ways,some by denying that there is a circle and some by admitting thecircularity but denying itssignificance. I will here briefly evaluate a few of their arguments.
Some commentators have taken a passage from Descartes’ reply to theSecond set of Objections(Mersenne’s) to indicate that Descartes is only actually interested inthe psychological significance offundamental truths. The passage is as follows:
“If a conviction is so firm that that it is impossible for us ever tohave any reason for doubting whatwe are convinced of, then there are no further questions for us to ask;we have everything we couldreasonably want.”
Under my interpretation, this is what it is about the cogito that makesit so important for Descartes,so we cannot have any argument with the principle expressed by him inthe above passage. But can ithelp break the circle? When we clearly and distinctly perceivesomething, Descartes says, fairly Ithink, that this perception compels our assent, that we cannot butbelieve it. God’s r?le in the system,to these commentators, is as a guarantor of our memory regarding clarityand distinctness. In otherwords, once we have proved God’s existence, we can happily know that anymemory we have of aclear and distinct idea regarding x is true i.e. that we really did havea clear and distinct idea of x. Butthis does not seem satisfactory, as we still do not have a divineguarantee for the reasoning that leadsus from the clear and distinct notions we originally have about God tothe proof of His existence. Wecan give assent to the clear and distinct notions we have originally; infact, we are compelled to givethis assent when the notions are presented to our mind, but the logicalsteps we take from these ideasto the final proof is still subject to the evil demon because God is notyet proven. Furthermore, becausethese steps are needed, the memory of the original clear and distinctideas are themselves subject todoubt because God is not yet proven. It seems that the only way eitherof the proofs of God could beaccepted would be if we had an original clear and distinct perception ofGod directly presented to ourmind (qualitatively similar to the cogito). But this in itself wouldmake any future proofs redundant.Interestingly, this sounds quite similar to a divine revelation.
Harry Frankfurt, in his book ‘Demons, Dreamers and Madmen’, has arguedthat what Descartes isactually looking for is a coherent, indubitable set of beliefs about theuniverse. Whether they are ‘true’or not is irrelevant. Perfect certainty is totally compatible withabsolute falsity. Our certainty may notcoincide precisely with ‘God’s’ truth, but should this matter?:
“Reason?can give us certainty. It can serve to establish beliefs inwhich there is no risk of betrayal.This certainty is all we need and all we demand. Perhaps our certaintiesdo not coincide with God’struth?But this divine or absolute truth, since it is outside the rangeof our faculties and cannotundermine our certainties, need be of no concern to us.” (Frankfurt, p184)
This is almost a Kantian approach to knowledge, where we as humans onlyconcern ourselves withthe phenomena of objects as they present themselves to us, not with theobjects in themselves. Can weascribe this view to Descartes? It’s tempting, given what we have saidabove regarding the primeimportance of indubitability, but it would seem that a God presentingideas to us in a form whichdoesn’t correspond to reality, and then giving us a strong dispositionto believe that they docorrespond to reality would be a deceiving God and contrary toDescartes’ notion of Him. Thus thebelief set would not be coherent. Perhaps, as we do not have clear anddistinct ideas of the bodies weperceive, and as the divine guarantee only extends as far as clear anddistinct ideas, we are being toohasty in judging that reality is how it appears to be and if we stoppedto meditate further we would seethat reality is actually like something else. But aside from the factthat this seems unlikely, Descartesnever seemed to envisage the possibility.
So much for the Cartesian circle. Where does this leave the ontologicalargument, which we had onlyjust begun to discuss? Aside from the methodological difficulties, theredo seem to two furtherproblems with it. The first has been noted by almost every student ofDescartes over the years – that ofthe description of existence as a property. Put briefly, this objectionstates that existence is not aproperty like ‘red’ or ‘hairy’ or ‘three-sided’ that can be applied to asubject, and thus it makes no senseto say that existence is part of something’s essence. If we assert thatx is y, we are already asserting theexistence of x as soon as we mention it, prior to any application of apredicate. from the beginning. Inother words, to say ‘x exists’ is to utter a tautology and to say that’x doesn’t exist’ is to contradictoneself. So how can sentences of the form ‘x doesn’t exist’ make sense?one may well ask. It is becausethese sentences are shorthand for ‘the idea I have of x has nocorresponding reality’ and it was tosolve problems like this that Bertrand Russell constructed his theory ofdescriptions. To add existenceto an idea doesn’t just make it an idea with a new property, it changesit from an idea into an existententity.
Finally, if Descartes is right, there seems no reason why we cannotconstruct any other idea whoseessence includes existence. For instance, if I conjure up the idea of’an existent purple building thatresembles the Taj Mahal’, then it is the true and immutable nature ofthis idea that it is a building,that this building resembles the Taj Mahal, that the building ispurple, and that it exists. But no suchbuilding does exist, as far as I am aware, and if it did exist, itsexistence would not be necessary, butcontingent. This in itself is enough, I think, to show that theontological argument is false.
Once we have destroyed Descartes’ proofs of the existence of God, theedifice of knowledgenecessarily comes tumbling down with them, as we find that almosteverything Descartes believes inis dependent on God’s nature as a non-deceiver:
“I remark?that the certitude of all other truths is so absolutelydependent on it, that without thisknowledge it is impossible ever to know anything perfectly.” (p.115)
The only possible exceptions are those assent-compelling beliefs suchas the cogito. Even these,however, are doubtful when we are not thinking about them, and the abovepassage does give weightto Edwin Curley’s argument that:
“Descartes would hold that the proposition “I exist” is fully certainonly if the rest of the argument ofthe Meditations goes through. We must buy all or nothing.”
This is not the end of the story, though. As far as Descartes isconcerned, by the end of MeditationFive, he has produced two powerful proofs of God, has a clear anddistinct notion of his own self, hasa criterion for truth, knows how to avoid error and is beginning to formideas regarding ourknowledge of corporeal bodies.. And so it remains only to explain why weare fully justified inbelieving in corporeal bodies, and also to draw the ideas of MeditationTwo regarding self-knowledgeto their full conclusion.
Regarding the nature of corporeal bodies and our knowledge of them, itseems to me that, given hispremises, the conclusions Descartes draws in Meditation Six aregenerally the correct ones. He againinvokes the causal to argue that the ideas of bodies we have within ourminds must be caused bysomething with at least as much formal reality as the ideas haveobjective reality. We couldtheoretically be producing these ideas, but Descartes dismisses thispossibility for two reasons – firstly,that the idea of corporeality does not presuppose thought and secondlythat our will seems to have noeffect on what we perceive or don’t perceive. (This second argumentseems to me to ignore dreaming,in which what we perceive derives from us but is independent of ourwill). The ideas, then, couldcome 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 ofbodies in us, then the verystrong inclination we have towards believing that the idea-producingbodies resemble the ideas wehave would be false and thus God would be allowing us to be deceivedwhich is not permissible. Thesame would apply if any other being were producing these ideas. Thus,concludes Descartes, it is mostlikely that our ideas of corporeal bodies are actually caused by bodiesresembling those ideas. Wecannot be certain, however, as we cannot claim to have clear anddistinct notions of everything weperceive. We can, however, claim certainty with regard to thoseproperties of bodies which we doknow with clarity and distinction; namely, size, figure (shape),position, motion, substance, durationand number (not all of these assertions are justified). Obviously wecannot claim that we know theseproperties for specific bodies with clarity and distinction, for to doso would leave open the question ofwhy it is that astronomy and the senses attribute different sizes tostars. What Descartes means is thatwe can be sure that these primary qualities exist in bodies in the sameway that they do in our ideas ofbodies. This cannot be claimed for qualities such as heat, colour, tasteand smell, of which our ideasare so confused and vague that we must always reserve judgement. (Thisconclusion is actually quitesimilar to the one John Locke drew fifty years later in his EssayConcerning Human Understanding.)
I think we can grant this reasoning, with the caveat regarding dreamingthat I noted above, and ofcourse the other unproved reasonings that Descartes exhumes here, suchas the causal principle.Furthermore, it seems to be further proof that Descartes does believe wecan get to know objects inthemselves to a certain extent.
Finally, I turn to Descartes’ argument for the distinction of mind andbody. Descartes believes he hasshown the mind to be better known than the body in Meditation Two. InMeditation Six he goes on toclaim that, as he knows his mind and knows clearly and distinctly thatits essence consists purely ofthought, and that bodies’ essences consist purely of extension, that hecan conceive of his mind andbody as existing separately. By the power of God, anything that can beclearly and distinctly conceivedof as existing separately from something else can be created as existingseparately. At this point,Descartes makes the apparent logical leap to claiming that the mind andbody have been createdseparately, without justification. Most commentators agree that this isnot justified, and further, thatjust because I can conceive of my mind existing independently of my bodyit does not necessarilyfollow that it does so. In defence of Descartes, Saul Kripke hassuggested that Descartes may haveanticipated a modern strand of modal logic that holds that if x=y, thenL (x=y). In other words, if x isidentical to y then it is necessarily identical to it. From this itfollows that if it is logically possible thatx and y have different properties then they are distinct. In thisinstance, that means that because I canclearly and distinctly conceive of my mind and body as existingseparately, then they are distinct. Theargument, like much modern work on identity, is too technical andinvolved to explore here in muchdepth. But suffice to say that we can clearly and distinctly conceive ofDr Jekyll and Mr. Hyde asbeing distinct and yet they are identical, necessarily so under Kripke’stheory. It is doubtful thatKripke can come to Descartes’ aid here and Descartes needs furtherargument to prove that the mindand the body are distinct.
And so we finish our discussion of Descartes’ attempts to extricatehimself from the sceptical doubtshe has set up for himself. As mentioned previously, the ultimateconclusion to draw regarding thesuccess of the enterprise that Descartes set for himself must be that hefailed. When the wholeepistemological structure is so heavily dependent on one piece ofknowledge – in this case theknowledge that God exists – then a denial of that knowledge destroys thewhole structure. All that wecan really grant Descartes – and this is certainly contentious – is thathe can rightly claim that when aclear and distinct idea presents itself to his mind, he cannot but givehis assent to this idea, andfurthermore, that while this assent is being granted, the clear anddistinct idea can be justly used as afoundation for knowledge. The most this gets us – and this is not alittle – is the knowledge of our ownexistence each time we assert it. But Descartes’ project should not bejudged by us as a failure – thefact that he addressed topics of great and lasting interest, andprovided us with a method we can bothunderstand and utilise fruitfully, speaks for itself.
1. Descartes, Ren? A Discourse on Method, Meditations and Principles ofPhilosophytrans. John Veitch. The Everyman’s Library, 1995.Descartes, Ren? The Philosophical Writings of Descartes volume I and IIed. and trans. JohnCottingham, R. Stoothoff and D. Murdoch. Cambridge, 1985.Frankfurt, Harry Demons, Dreamers and Madmen. Bobbs-Merrill, 1970.Curley, Edwin Descartes Against the Skeptics. Oxford, 1978.Vesey, Godfrey Descartes: Father of Modern Philosophy. Open UniversityPress, 1971.Sorrell, Tom Descartes: Reason and Experience. Open University Press,1982.The Oxford Companion to Philosophy ed. Ted Honderich. Oxford UniversityPress, 1985.Cottingham, John Descartes. Oxford, 1986.Williams, Bernard Descartes: The Project of Pure Enquiry. Harmondsworth,1978.Russell, Bertrand The History of Western Philosophy. George Allen andUnwin, 1961.11. Kripke, Saul Naming and Necessity. Oxford 1980.
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