The 17th Century philosopher and “father” of modern philosophy in the West, René Descartes’ argument, “I think, therefore I am,” is familiar to many. It is bound up with the historic beginnings of a major turn in philosophy, a destructive but influential and pervasive departure from the more Christian and Classical philosophy which persisted for millenia. Intended as a counter to radical skepticism, it seeks to discover an incontrovertible foundation for epistemic certainty. Rather than providing an antidote to radical doubt and skepticism, however, Descartes’ argument, “I think, therefore I am” (in Latin: cogito ergo sum; in the original French: je pense, donc je suis), is instead a logical fallacy. It is circular reasoning, a petitio principii, a begging of the question, an assuming of the desired conclusion in the premise. A vicious circle, at best it is a tautology.
The initial premise, “I think,” is enthymematic (an enthymeme is “an argument in which one premise is not explicitly stated”); it tacitly asserts the desired “am.” When it states, “I think,” it is implicitly saying, “I [am] think[ing],” thus inserting being prior to proving being. To make such an argument is thus to self-destructively assert an epistemological certainty for the very being he is trying to prove, the very conclusion the argument is attempting to accomplish. In short, viciously circular, it is saying “I, therefore I.”
The statement itself can be read in more than one way. Two primary ways would be either as an ontological statement or as an epistemological one. Neither way avoids the difficulty it is entangled in. For example, reading it in an ontological key, since Descartes axiomatically presupposes being as a certainty, vis a vis “I [who am] think,” then certainty of being cannot be reached as the conclusion of the argument such that he can say, “therefore I am.” That is simply restating, or making explicit, the implicit premise as the conclusion. If, however, it is read in an epistemological key, then the circularity yet remains, for to claim “I think” is enthymematically to assert “I [am epistemologically certain I] think.” In essence still restating the implicit premise in an explicit form as the conclusion, he is stating, “I know, therefore I know,” which is facile and self-defeating since the purported enterprise of the cogito ergo sum is to discover an indubitable foundation for certain knowledge. If certain knowledge is assumed within the initial premise, then it cannot become the certain conclusion without also becoming viciously circular.
To say “I am not” is absurd. Quite simply, there is no additional act which gets added to the “I” which “proves” said “I.” The “I” is presupposed in all acts, for “I” means ‘being in the act of personal existence,’ or ‘being existing,’ and, as such, “I” is the necessary foundation of all action. As such, no additional or subsequent act “proves” the “I,” only reveals it relative to and through some particular act. To reveal, however, is not the same as to prove. Only an “I” can even attempt to prove, and so the attempt alone has already presupposed the I’s existence, thus rendering proof unpersuasive and without warrant.
The “I” reveals itself in and through its acts, rendering the acts signs of the "I." In this sense, thinking is no different from breathing or knowing or even doubting, for in each of these acts an “I” is necessarily presupposed. In this light, Descartes’ statement could equally be, “I breathe, or know, or even doubt, therefore I am,” which ends up tautologically breaking down to, “I am, therefore I am.” Instead of referring for proof to something the "I" does per accidens, which is to say one of its innumerable potential acts, the "I" instead reveals itself principally via the fundamental act of existing, and consequently by various and sundry doings. It is perhaps worth mentioning that existence does not cease with the cessation of thought, as in dream or deep sleep. In this sense, it could perhaps be said, "I am, therefore I think." In short, one does not prove an I, one is an I.
Recasting the cogito in a more explicitly epistemological light will not help, for to say the certain fact of his thinking enables him to have certain knowledge that he exists is really unremarkable since the ability to think, know, and be aware is precisely what makes self-knowledge realizable. It is epistemic certainty he is after, and as such the question can be posed: How does Descartes really know he is thinking? Is there no possible reason for skepticism? For example, philosophers such as Siddhartha Gautama and David Hume arguably find nothing persuasive in the assertion that there really is a self at all, that, “acts without an agent,” what is commonly called “I” is “nothing but a bundle of different perceptions.” In other words, thoughts do not necessarily prove a thinker, for Gautama and Hume seem to say, "There is thinking, but I am not," and so it is dubious for Descartes to certainly assert “I think” simply because thinking is present, especially when it is theoretically possible to deny substantial reality to the supposed self. Moreover, since selves can be argued on rational grounds not to exist, it may be possible to render thoughts as impersonal reactions within a fundamentally impersonal environment, therefore not proving the existence of personal being at all. Thus, Descartes has not found epistemic certainty in his assertion, “I think,” for it is entirely possible to rationally doubt that there is a thinking “I.” In assuming the "I" in the "I think" premise, it seems suspicious to find a certain "I am" in the conclusion, as if he seeded the sought outcome in his initial sowing.
Moreover, another elephant in Descartes’ room is that thinking is not exactly the same as knowing. Thus, if one were to hypothetically exclude knowledge of thinking from the cogito’s premise, to say in effect, “(While not knowing that) I think, therefore (I know) I am,” it is noteworthy that the "therefore" does not necessarily follow, for not all acts of thinking imply acts of true knowledge. People can think untrue thoughts. If excluding knowledge from the premise, it presumes that certain knowledge can be a consequence, product, or result of uncertain thinking, or that thought necessarily converts to certain knowledge, which has yet to be demonstrated. If he says, "I think," then thinking of what? Swans? Daffodils? Thinking itself? By thinking of thinking he is certain of being? It seems inescapable that by stating "I think," he actually means "I know I think," which again inserts epistemic certainty into the premise.
Knowledge, of course, could also be cast, more Platonically, as anamnesis, a concept which is akin to recollection, recognition, and remembering, and not so much to thinking per se. And so how thinking converts into certain knowledge again remains untouched. To say thinking proves a thinker is facile, at best, or flat out wrong if one were to agree with Gautama or Hume, as mentioned above. To say knowing proves a knower is equally facile, again if not dubious. Perhaps it would be accurate to state that “he thinks, therefore he thinks he is,” but how he actually gets to certain knowing from thinking remains undisclosed and unproven.
What is worse, he has to somehow be epistemically certain that he is thinking, which as noted above inserts the desired epistemic certainty in the premise. If the truth or falsity of any particular thought is treated as irrelevant, merely the existential fact of thinking, then it again becomes tautological. In other words, if he knows he is thinking, then he already has the certainty he seeks and thus cannot arrive at this certainty as a conclusion without falling again into viciously circular reasoning. Whether interpreting the stress as being on the ontological or the epistemological view of the cogito, both emphases necessitate an epistemic certainty in the premise in order to assert either the certain being who is thinking, or the certain knowledge that said being has. In other words, he must know that they are, in truth, thinking, and not, say, sitting, wondering, or whistling.
Existence, which is to say being, is presupposed in all acts, including acts of thinking and reasoning about existence, and thus existence (implicit in acts) cannot become a premise of its own proof. Likewise, knowledge is presupposed in all assertions, including assertions about knowledge, and so knowledge (implicit in assertions) also cannot become a premise of its own proof. On the one hand, if seeking to find certainty for existence via thinking, then one has to assume the certain existence of the thinking agent, and so one can never arrive at certain existence as a conclusion because it was already enfolded in the premise. On the other hand, if seeking to find certainty for knowledge via thinking, then one has to assume that one is certainly knowing that thinking is happening, and that a being is doing it, and so one can again never arrive at certain knowledge as a conclusion because it was already implicit in the premise. Descartes’ argument therefore fails both as ontology and epistemology due to its intrinsic, self-defeating circularity.
To conclude, the phenomenon of self-awareness of personal being is an overwhelming fact for a person, which as a fact is not proven so much as submitted to and subsequently employed in all acts, including acts of knowledge and proof. Just as one does not look into a mirror to prove one sees or has eyes, much less that one exists, likewise one does not resort to an extrinsic logical proof in order to establish certain knowledge that one exists or that one can know things with certainty. The use of knowledge in generating assertions inescapably presupposes the reality of knowledge prerequisite to asserting. Assertions thus are a consequence of knowing, and are not knowing’s ground, as a wave does not wet an ocean, nor a leaf give birth to a tree.
One must presuppose epistemic certainty as a criteria and guide in order to prove that knowledge of x or y is certain, for the persistent multiplication of ignorance does not of itself produce certain knowledge as if sui generis, for even denying certainty is a type of certainty - a certainty of uncertainty. Likewise, one must presuppose epistemic certainty if one is reasoning on its behalf, for without it there would be no reasoning; there would be no rational criteria by which Descartes could know that his epistemic certainty was in fact certain if there was no rational substructure to which he implicitly and at all points was relying upon and being guided by in his acts of reasoning. And so, in sum, Descartes failed at the start; he has not proven anything, merely fallen victim to vicious circularity.
