Johannes Climacus wrote:The contrapositive for the Cogito would be
I am not, therefore I do not think.
If P then Q
If not Q then not P
Having given this brief thought I think it is clear that the counter indicative of "I think, therefore I am" is a non-trivial result.
Descartes' allows himself to do away with every allowable misconception and finds that in the end, he still thinks. He concludes that since he thinks, he is. However this is only true if it also follows that when or if he is not, he does not think.
Descartes' establishes that he is, because he thinks. But in order for that to be true it must also be the case that if he is not, it follows consequently that he will not think. But Descartes has already established that it is impossible for him not to think. Descartes in fact establishes that he is - from the fact that it is impossible for him not to think. So whether or not Descartes assumes an existential state in which he is not, he has already concluded that it is impossible for him not to think.
But the nihilist in all of us might point out that Descartes only establishes that he is, because he must think, but only so long as he lives and breathes. If he dies, and for all intents and purposes we can say that Descartes is "not", it is a simple, obvious supposition to assume that he consequently does not think thereafter. Hence, any truthful validity to Descartes counter indicative relies on his testimony in the after life. And few of us have anything to say about that, so the counter example stands on the basis of us not being able to come back from the dead and say anything to the contrary.
Fair enough. "Cogito, ergo sum" stands on the basis of not knowing the afterlife. But, the question is a matter of "being". Descartes assumes that because he can think, he has being. But this only is true if he can also NOT have being, and in that case not have thoughts. Once again, ordinary thinking may lead us to believe the proof in the pudding lies in the rotting of our dead bodies. But existentialists like Jean Paul Sartre will tell you in great detail that you in fact do not have being. Or they will demonstrate that if you do have being, whatever being that is, is a non-being. Sartre has explained that "consciousness is a being such that in its being, its being is in question insofar as this being implies a being other than itself."
If that is the case, and I believe it is, and Sartre would probably conclude that this is the whole point of his philosophy, the truth of Descartes' Cogito is completely backwards. In fact it
should be the case that "I think, therefore I am not."
In Sartre's terminology, and in the terminology established before him, there is:
Being (être): Including both Being-in-itself and Being-for-itself, but the latter is the nihilation of the former. Being is objective not subjective or individual.
Being-in-itself (être-en-soi): Non-conscious Being. The sort of phenomenon that is greater than the knowledge that we have of it.
Being-for-itself (être-pour-soi): The nihilation of Being-in-itself; consciousness conceived as a lack of Being, a desire for Being, a relation of Being. The For-itself brings Nothingness into the world and therefore can stand out from Being and form attitudes towards other beings by seeing what it is not.
To see if the reverse Cogito can stand it must follow, the logic must be...now let me see...if P, then not Q ---> If Q, then not P. This means, "If I am, then I do not think!"
Sartre's conception of being is "being-in-itself-for-itself". So if I "am" anything, I am this same "being-in-itself-for-itself." But, as Sartre explains, we are never "being-in-itself-for-itself", only "being-for-itself" desperately attempting to realize "being-in-itself" with no rewards.
Still, if we were not only "being-for-itself", but also "being-in-itself", then we would have that property of being non-conscious. If we really
were something, as in "having being", we would consequently not have thought, since being-in-itself has the property of existing in a non-conscious state. This proves that the initial statement "I think, therefore I am not" is a sound one.
It is more sound than Descartes' statement because it can establish the validity of its own counterpositive statement, whereas the validity of Descartes' counterindicative proposition can not be established by any one other than a dead man. And dead men do not tell secrets.
"Existentiam numen Dominus." - even twice a day a broken clock is right.