Descartesâ First Proof of Godâs Existence
P1 - The cause must be at least as perfect as the effect.
P2 - The idea of God must have a cause.
P3 - The idea of God is of a perfect being.
C1 - The idea of God is itself perfect (If the idea is of something perfect, the idea itself is perfect).
P4 - I am not perfect.
C2 - I cannot be the cause of my idea of God.
C3 - Something else must exist to be the cause of my idea of God.
C4 - By P1, this thing must be at least as perfect as my idea of God.
P5 - Only God is at least as perfect as my idea of God.
C5 - God must exist.
Critique:
P1 is not particularly clear in its meaning. What does "perfect" mean here? What are Descartesâ criteria for perfection in such a general proposition? And are there degrees of being perfect? Normal usage of the term "perfect" is for a quality that is instantiated or it is not, as in a perfectly straight line. Either a line is perfectly straight or it is not. We do not use the term to indicate matters of degree, hence we donât say things like "Line A is more perfectly straight than line B." Perfection is a two-valued function, not a continuous variable. Something is either perfect in some regard (by some criteria for perfection) or it is not. We do, on the other hand, talk of degrees of imperfection, as in the degree of deviation of a curved line from a straight line. Since P1 is not clear in its meaning, it cannot be, by Descartesâ own criteria for self-evidence, self-evidently true.
P2 is, by Descartesâ Causal Principle "Something cannot come from nothing," true only if his idea of God has not come about, that is, if it has not always existed. If it has always existed, then, like Descartesâ God, it does not require a cause. To ask if Descartesâ idea of God has always existed is to ask if Descartesâ mind has always existed. Can Descartes know with certainty that his mind has not always existed? He may lack memories of such a long existence, but a lack of memory proves nothing. Descartes probably cannot remember anything from his first two years of infancy. Does that prove he didnât exist then? And Descartes cannot make use of birth certificates, county records, testimony of his parents, and other external-to-his-mind sources because he has yet to prove the existence of a world external to his mind. Descartes has not proven that his mind and this idea of God in his mind have not always existed, so the truth status of P2 is questionable.
P3 , Descartesâ concept of God, is, for Descartesâ, a self-evident given, and I suggest we give him the benefit of the doubt here and play along with him.
C1 is rather strange. Descartes is trying to show that he is not perfect enough to be the cause of his idea of God. P1 tells us that Descartes, being imperfect, cannot be the cause of anything more perfect than he, himself, is, so he certainly cannot be the cause of God. But Descartes can conclude that he cannot be the cause of his idea of God only if this idea itself is more perfect than Descartes. So the question becomes, if an idea is about something perfect, does that necessarily mean that we must, via some rule of logic, attribute perfection to the idea? How about a photograph of something perfect, say a snowflake. Is the photograph perfect because itâs topic is perfect? We donât normally talk about ideas as being perfect (other than meaning well suited to some desired end), though we may characterize some ideas as true or correct. But does "true" always mean "perfect?" I may have the idea of a pimple on my nose, and if I actually have a pimple on my nose, then my idea is true. But, is there some rule of logic that requires I attribute perfection to my idea of the pimple on my nose? If so, I would like to know what rule of logic dictates this. Someone please tell me. Descartes hasnât. I havenât come across any such rule in the philosophical literature. Now, I might chose to call true ideas perfect ideas. Iâm free to do so if I want to for some reason, but am I logically bound to do so? I might call ideas of perfect forms perfect ideas, but am I logically bound to do so or is this just a matter of semantics, that is, how you or I or Descartes chooses to use to word "perfect" in relation to ideas?
Even if we were to feel compelled to attribute perfection to such ideas, does that necessarily mean that the possessor of such ideas is less perfect than the ideas themselves? Presumably, Descartes could exist without such ideas in his mind, but could they exist without his mind? And if one thing exists dependently upon another but the latter thing exists independently of the former thing, then is not the independent thing more perfect (of a less conditional existence) than the dependent thing? Descartes often reasons in just this way. For Descartes, actual existence is more perfect than existence merely as an idea. Indeed, Descartesâ third proof of Godâs existence depends on this. Since Descartes, though imperfect, is at least as real as any of his ideas, perhaps he is also at least as perfect as any of his ideas. Can he be sure otherwise?
P4, I, "Descartes, am not perfect." I suggest we agree with Descartes on this one. (I know Iâm not perfect.)
C2,"I cannot be the cause of my idea of God." This conclusion follows from P4, P1 and C1. Since there is uncertainly in P1 and C1, there is uncertainty in C2 and everything else that follows, including C5 ,"God must exist." (An argument is only as strong as its weakest link.) While God might exist and might be the cause of Descartesâ idea of God, Descartes fails to prove that this must be so.
