"Descartes' attempt to prove the existence of God in Meditation III is not merely a failure, it is a philosophically uninteresting failure."Discuss.

The most immediate challenge that arises from this title question is, given that Descartes'proof is actually a failure, just what might constitute a "philosophically uninteresting"failure?   In the absence of any guidance to the contrary, I am going to suggest that a "philosophically uninteresting"failure of an argument is one that results from a simple failure of imagination.   Given the premises with which Descartes starts, and given the then current cultural milieu within which he developed his arguments, it is not very surprising that he did indeed suffer from the failure of imagination that he did.   For it took 150 years and a genius every bit as impressive as Descartes to give expression to the short-coming of imagination that trips up Descartes reasoning in his attempt to prove the existence of God in Meditation III.

To describe where and how this failure of imagination creates the failure of logic in Descartes'attempt to prove the existence of God, and why it is really a "philosophically uninteresting"failure, I am going to have to describe the details of Descartes reasoning.

The concept of "Essence"was an important concept in Scholastic philosophy.   An "essence"was taken by the Scholastics to be that quality or property that made something the type of thing that it is.   (The essence of man, for example, is "rational thought", because it is rational thought that supposedly distinguishes man from all other things.)   According to the Scholastics, a substance is the most basic unit of existence.   Descartes takes these Scholastic concepts, and by introducing the notion of a "mode", reduces the types of substances in the world from an innumerable plurality to only two " body and mind.   (God he considers a variation on the substance of mind).   Descartes reasoned that there are only two essences in the world " the essence of mind (thought); and the essence of body (extension).   According to Descartes a "mode"was a determinate way of being an attribute of one of these substances.   All modes of body are determinate ways of being extended.   All modes of mind are determinate ways of being thought.

From his background in Aristotelian / Scholastic metaphysics, it seemed so obvious to Descartes that substances exist, that he held we must conclude that a substance is necessarily present wherever we encounter a property.   It never occurs to him to subject the concept of substance to criticism in accordance with his program of systematic doubt.   Although he was prepared to doubt the existence of things that are observed by us, he was not prepared to doubt the existence of a substance even though it is not observed by us.  

Using his Method of Doubt he systematically examines all his beliefs and sets aside those which he could call into doubt.   He finds only one belief which he can not doubt -- that the evil genius seeking to deceive him can not deceive him into thinking that he does not exist when in fact he does exist.   By the end of the Second Meditation, Descartes claims to have succeeded in discarding as dubitable all but his knowledge that he thinks, and that he exists.   In his effort to demonstrate that God exists, therefore, he can draw upon nothing beyond the thoughts ("ideas") that he thinks.  

"Now, with respect to ideas, if these are considered only in themselves, and are not referred to any object beyond them, they cannot, properly speaking, be false;"Vetch, Pg 236

With this limited foundation, then, Descartes begins his proof by establishing some classification schemes for his ideas.   He observes that his thoughts, his ideas, when considered only as ideas, fall into three different classes.  

"But among these ideas, some appear to me to be innate, others adventitious [that is to be caused by things outside of me], and others to be made by myself (factitious);"Vetch, Pg 237

Although he, at this point admits that he has "not yet clearly discovered their true origin".

Descartes establishes the distinction between "objective reality"and "formal reality".   According to an explanatory footnote provided by Cottingham and Stoothoff, "Having more objective reality"means:

". . . participation by representation in a higher degree of being or perfection."(added in the French version).   According to the Scholastic distinction invoked in the paragraphs that follow, the "formal"reality of anything is its own intrinsic reality, while the "objective"reality is a function of its representational content.   Thus if an idea A represents some object X which is F, then F-ness will be contained "formally"in X but "objectively"in A."
                Cottingham, Pg 90

A thing (particularly, an Idea) has "objective reality"in virtue of representing something else.   Descartes originally posits the concept of objective and formal reality as a way to explain the difference between an object in the real world, and the idea of that object in our minds.   But at this point in his reasoning, he applies the classification only to the ideas of his mind.   (He does not say whether other representational entities, such as paintings, might also have "objective reality".)   According to Descartes, the amount of objective reality an idea has is determined solely on the basis of the amount of formal reality contained in the thing being represented.   "Formal reality"is simply the reality that something possesses in virtue of existing.   Formal reality is what he takes to be the cause of his ideas, while the ideas in themselves represent objective reality.  

Descartes then applies his classifications of ideas to his notion of "substance".   Since he believed that modes of substances (properties) were accidental modes of the underlying substance, he argued that the underlying substance has more "objective reality"than the modes.   His reasoning is that the underlying substance itself must be "more perfect"than could be any variations of that substance that are the modes we observe.

"For, without doubt, those 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;"
                Descartes / Vetch, Pg 239.

The next step in his argument is the critical one.   It is his premise that "Now, it is manifest by the natural light that there must at least be as much reality in the efficient and total cause as in its effect;"[Vetch, Pg 239] and "it is not less repugnant that the more perfect should be an effect of, and dependence on the less perfect"[Cottingham pg 172].   This is the key premise of an "argument from design".   Having classified the three categories of ideas according to his notion of "perfection", he then maintains that the cause (the formal reality) of some level of perfection must be equal to or greater in perfection than the idea that is the effect (the objective reality).

Descartes continues to say that any thing that is the effect of another thing may contain in it only the qualities (modes) expressed in the cause.   He uses the example of a stone.   The idea of something like the stone, cannot exist clearly and distinctly in one's mind unless it was put there by a cause which contains at least as much formal reality as the objective reality of the idea. "[T]here must at least be 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?"[Cottingham pg 172]

"When we apprehend that it is impossible a thing can arise from nothing, this proposition ex nihilo nihil fit, is not considered as something existing, or as the mode of a thing, but as an eternal truth having its seat in our mind, and is called a common notion or axiom."
              Descartes / Vetch, Pg 319

Having thus set the necessary groundwork, Descartes then establishes his "Proof"of the existence of God.   He starts with the premise that he has an idea of absolute perfection -- an idea of God.   This idea, being an idea of his mind, has an objective reality.   But, he asks, what is the cause of this idea.   By his definition of objective and formal reality, he can conclude that whatever the cause, it must have at least as much formal reality as it does objective reality.   Since his idea is that of absolute perfection, then the cause of the idea must also possess absolute perfection.   Therefore, this idea cannot have an adventitious cause, since it has already been demonstrated through his method of doubt that the senses are flawed and hence imperfect.   Nor can this idea have a factitious cause (be made by himself), since it has already been demonstrated that he can be fooled by his evil genius, so that he, himself, must be considered flawed and imperfect.   Therefore, his idea of God must be innate.   But if it is an innate idea, what has caused the creation of such a perfect innate idea.   The innate idea of absolute perfection must be the effect of a cause that has at least as much formal reality.   Descartes reasons that the only way that he could come by this innate idea of his of an absolute perfection, is if something of equal or greater perfection caused the idea in him.   Therefore God must exist.

Descartes is not making the error of confusing a muddled notion of a supremely perfect being with a supremely perfect notion of a supremely perfect being.   There is no difficulty with the notion of a flawed and error-prone mind creating a flawed and error-prone notion of a supremely perfect being.   But Descartes takes his notion of God to be a supremely perfect notion.   His notion of God is a prototypical "Grand Unified Theory"that explains and deductively predicts everything.

'the fact remains that it was a huge theory, full of intricacy, remarkably self-consistent, often fiendishly persuasive even in today's hindsight. Any idea that could generate such a stunning intellectual edifice would be a prodigiously fecund idea, and if the edifice were true in all particulars (as Descartes thought his edifice was), the fact that such an idea was to be found in a mind would be something aching for explanation."
              Dennett, Pg 8

In several places within his body of work, Descartes draws upon the analogy of a highly intricate machine.   And he argues that if someone has an idea of such a machine, and has not himself the capacity to imagine the level of intricacies contained within that machine, then it is natural to conclude that the design of the machine has come from someone else.

'this is illustrated in the Replies by the comparison of a highly perfect machine, the idea of which exists in the mind of some workman; for as the objective (i.e., representative) perfection of this idea must have some cause, viz, either the science of the workman, or of some other person from whom he has received the idea, in the same way the idea of God, which is found in us, demands God himself for its cause."
              Descartes / Vetch, Pg 217

Unfortunately for Descartes, the argument from design is quite flawed, of course.   And the erroneous premise is the presumption that "perfection"(or "design") can only be created by something of greater "perfection"(or "design").   When Charles Darwin published his The Origin of Species, in 1859, he provided another explanation of how "perfection"(or "design") can arise "from nothing".  

"Until Darwin came along, Descartes had a pretty compelling reason for believing in God. He had found some Intelligent Design within the confines of his own mind, and you don't get Intelligent Design for free. Something pretty special has to account for it. What Descartes could not have imagined -- or, like Hume, could not have taken seriously if he did imagine it -- is the hypothesis that all this wonderfulness, all this design, can have a non-divine ultimate cause: evolution by natural selection."
               Dennett, Pg 10

Evolution is an explanation that has proved remarkably versatile and powerful.   Evolution is a possibility that renders Descartes critical premise quite false, thereby rendering his "proof"of the existence of God quite unsound.   Darwin argued, and science has since adequately demonstrated, that Descartes'key premise in his "argument from design"is false.   Descartes failure is fundamentally a failure in imagination.   And a simple failure of imagination is, unfortunately for Descartes, is philosophically uninteresting -- there are no further philosophical ramifications to the failure of the proof..   The failure is uninteresting in the same way, and for the same reasons that modern efforts by the "Intelligent Design"community are philosophically uninteresting -- they are founded on a premise that is clearly false.


Cottingham, John & Stoothoff, Robert (translators);   Descartes, Selected Philosophical Writings, Cambridge University Press, Cambridge, England. 1988. ISBN 0-521-35812-4.

Dennett, Daniel C.;   Descartes Argument from Design.   Tufts University.   2006.   Downloaded August 15, 2008.   URL=<http://ase.tufts.edu/cogstud/papers/descartesdesign7.pdf>

Williams, Bernard;   Descartes: The Project of Pure Enquiry, Penguin Books, New York, New York. 1990. ISBN 0-14-013840-4

Vetch, John (translator);   Descartes: The Method, Meditations, and Philosophy, Universal Classics Library, Walter Dunne Publisher, London, England, 1901. downloaded from The Online Library of Liberty, August 8, 2008. URL=<http://oll.libertyfund.org>

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