商标论证
Criticisms of the trademark argument

Cunning notes that “Commentators have argued that there is not much hope for the argument from objective reality.” Wilson says that she will say little about Descartes arguments for the existence of God for “while these arguments are interesting enough, I don’t think Descartes is in a position to defend their soundness very forcefully.” Williams comments that “Descartes took these hopeless arguments for the existence of God to be self-evidently valid, conditioned in this by historical and perhaps also by temperamental factors.”
Hobbes' complaint that Descartes hasn't offered an adequate account of degrees of reality doesn't seem to have been answered and Descartes’ response that it is ‘self-evident’ surely isn't enough. There may be some superficial appeal in the claim that an actual flower has more reality than an idea of a flower but this needs to be unpacked. ‘Reality’ cannot be equated with ‘existence’ for, apart from the fact that ‘degrees of existence’ is hardly less problematic than ‘degrees of reality’, as Wilson comments, “reality must not be confused with existence: otherwise the existence of God would be overtly assumed in the premises of the argument.”
Even if the argument is judged on its own terms and we grant that there can be degrees of formal reality and degrees of objective reality there are still significant problems. Crucial to the argument as it is normally reconstructed is that the degree of objective reality is determined by the degree of formal reality that the thing being thought about would have if it existed. Descartes offers no reason why this should be so. Wilson says, “Descartes has simply made an arbitrary stipulation here.” There seems to be no good reason why we couldn't maintain different degrees of objective reality but insist that the idea of an infinite substance still has less reality than the amount of reality conferred by the formal reality of a finite substance.
Descartes may be inconsistent on this point for in the Replies he says of objective existence, “this mode of being is of course much less perfect than that possessed by things which exist outside the intellect; but, as I did explain, it is not therefore simply nothing.” Despite what Descartes appears to say in the Meditations it may be necessary for the objective reality to be less than the formal reality of the thing represented. Williams points out, “God, as the argument insists, has more reality or perfection than anything else whatever. Hence if Descartes’s idea of God is not itself God (which would of course be absurd), it cannot, however regarded, possess as much reality as God, and hence cannot demand as much reality in its cause as God possesses. So the argument seems to fall short of positing God as cause of the idea.” He goes on to say that Descartes must, therefore be relying on something more than the general principle that there must be as much formal reality in the cause of an idea as there is objective reality in the idea itself. Instead, he suggests, Descartes is relying on special features of the idea of God: “the infinity and perfection of God, represented in his idea, are of such a special character, so far in excess of any other possible cause, that the only thing adequate to produce an idea of that would be the thing itself, God.”
Then there is the problem of how it can be possible for a finite mind to have a clear and distinct idea of an infinite God. Descartes was challenged on this and in the first set of Replies says, “the infinite, qua infinite, can in no way be grasped. But it can still be understood, in so far as we can clearly and distinctly understand that something is such that no limitations can be found in it, and this amounts to understanding clearly that it is infinite.” Cottingham argues that making this distinction is “an unsatisfactory line of defence” He refers to Descartes own analogy of a man who had an idea of a very complex machine from which it could be inferred that he had either seen the machine, been told about the machine or was clever enough to invent it. He adds, “But clearly such inferences will hold only if the man has a quite determinate idea of the machine. If a man comes up and says that he has an idea of a marvellous machine which will feed the hungry by making proteins out of sand, I shall be impressed neither by his experience nor by his powers of invention if it turns out that that is all there is to the idea, and he has no conception, or only the haziest conception, of how such a machine might work.”
Finally, it might be added, for this proof to do the work Descartes is asking of it the proof needs to be clear and distinct. Given the above considerations this is unconvincing. In the second set of replies Descartes says this is the fault of the reader:
“I do not see what I can add to make it any clearer that the idea in question could not be present to my mind unless a supreme being existed. I can only say that it depends on the reader: if he attends carefully to what I have written he should be able to free himself from the preconceived opinions which may be eclipsing his natural light, and to accustom himself to believing in the primary notions, which are as evident and true as anything can be, in preference to opinions which are obscure and false, albeit fixed in the mind by long habit… I cannot force this truth on my readers if they are lazy, since it depends solely on their exercising their own powers of thought.”