1) Everything that thinks exists.
2) I think
Thus 3) I am.
Descartes is of the opinion that that the self-evidence of sum is perceived, rather than be deduced from cogito. This seems to suggest that the cogito is an unnecessary part of the proposition. Rather than the realisation of thinking causing one to realise that one’s existence is not in doubt, Descartes seems to be suggesting that the mind is automatically aware of its own existence that it immediately grasps the truth of the entire statement. This, though, makes the cogito redundant. The mind is just as able to grasp the truth of “I exist” without needing to consider whether it is thinking or not. “I exist” is a self-verifying sentence: to deny it would be as absurd as to say “I am currently absent”. Hintikka, though, suggests that these two words alone do not necessarily make it true (an amusing example is offered of weighing machines saying “I speak your weight” – it is not inferred from this that the weighing machine is a conscious being), but that the cogito has a “performatory” role in allowing the conclusion, “I am “, to be true for the particular thinker. This makes the indubitable nature of the cogito perceived not through the actual thinking, but because it is actively thought of. Williams suggested that Hintikka’s suggestion of “performatory” role for the cogito did not involve making the entire proposition true, but offering a reason why “I exist” cannot be doubted. In either interpretation, our knowledge of ourselves can be suggested to be secured through the cogito.
An important reason why the cogito cannot be considered a syllogism is the common suggestion that, under the logical form set out above, one could replace “I think” with “I walk”. This is pointed in the Objections, although the response Descartes gives points out why “I think” is the preferred term. Descartes, at this stage in the Meditations, is unable to be certain that he has a physical body: it is still open to doubt. Descartes, though, suggests that one would have to say, “I seem to be walking,” in order for the proposition to be as certain as the earlier form. The use of the verb “seem”, though, implies thought, thus this formation would be adding nothing new to the original form of the cogito. Again, though, one can only be sure of the fact that one is thinking and existing – nothing more can be drawn from it.
Descartes is implying that the conclusion is intuitively known from the premise, thus there is just one mental act which comprehends it all. However, to say that one intuits one’s knowledge of one’s mental self, and then infers from this that one exists, whilst denying that one flows from the other (they are all understood immediately) seem to be contradictory. To say that by thinking, one automatically recognises one’s existence is to suggest “therefore I exist” is a conclusion to the syllogism described above. The only alternative is to suggest that there is an innate knowledge of one’s existence inside everyone, and that it reveals itself through mental processes: this, too, whilst providing a secure base for knowledge does not avoid inferences.
Part of the way the cogito achieves this degree of surety regarding our knowledge is its reliance on the mind being transparent to the individual. Descartes’ method involves the need for introspection. Markie has commented that, when one does this, one is not aware that one is thinking, but rather that there is thought. With this alteration, one cannot infer, or be certain, that one exists. Moreover, there are some thoughts and ideas about ourselves that cannot be seized upon as easily as others, like emotions. This, though, is an irrelevant argument: it is the fact that one can seem to be having such-and-such a feeling, or can grasp some elementary ideas which the introspection requires.
Another flaw in the cogito is the actual definition of “I think”: Descartes does not specify what kinds of thoughts are covered by this term. Descartes himself defines “ a thinking thing” as one that “doubts, understands, affirms, denies, is willing, is unwilling, and also imagines and has sensory perceptions”. It may presumed that Descartes considers this list to be illustrative rather than definitive, as otherwise Descartes would be drastically limiting the mind (albeit a finite mind). Williams rightly points out that although this group of propositions about mental life may be incorrigible, there are others (like emotions or being able to picture colours) that are not. Moreover, subconscious or unconscious processes also have to be taken into account. When one is in deep sleep one cannot be actively thinking, thus knowledge of one’s existence cannot have any ground, even though parts of the brain are still active and processing information (an example is the way the noise of fire alarms is able to be interpreted by the brain and make it take the necessary action). Of course, there is no certainty that one will ever wake up, but it can be argued that grounds for one’s existence, based on the cogito, may still exist, albeit in a way the conscious mind cannot access. This, though, is to misunderstand Descartes. The proposition is only true, whilst it is being contemplated. For that moment, he can be certain of his existence, and from this it can be inferred that he is existing whilst his attention is on different things.
For these reasons, Descartes is aware that there is a mysterious “I” in the cogito, and that it can only work in the first person. “He thinks, therefore he exists”, is not as certain as its first person alternative. One can say “he doe not exist”, and have grounds for saying that. To refer to the first person, though, makes its truth self-evident: it is inconsistent to say such a thing. The reliance on the first person, though, shows that the cogito can only prove that one exists, and is therefore not a secure ground for any knowledge other than that. One may be certain that he exists, and the person next to him may also be using the cogito to verify his existence. There is no way both of them can be as certain of each other’s existence as they are of their own. The cogito very quickly leads one to solipsism.
Another problem with the cogito and its ability to securely ground knowledge is the apparent contradiction in the Meditations regarding what one can be certain of. Descartes maintains that he can only be certain of things which he can clearly and distinctly perceive. Although he never asserts that he clearly and distinctly perceives his ability to think, and thus his existence, he says he is certain of it, which, following Descartes’ method, suggests that he does clearly and distinctly perceive it. But by the Third Meditation this has been called in to doubt when he maintains that, prior to assuring oneself of the existence of God, even clear and distinct perceptions are open to manipulation by the malicious deceiver. Descartes appears to be asserting that an atheist would therefore have nothing to rest his own clear and distinct perception of his existence on, thus it would not be certain. If Descartes himself is therefore taken as a guide, until one is assured of the existence of God, even the cogito is in doubt, which means that by his own standards he has not secured knowledge of himself.
Even so, the cogito still does not securely ground knowledge. As has been discussed, it merely secures a ground for knowing that the experiences one has in one’s minds are in fact occurring in one’s mind. Nothing more can be obtained from it, and so to claim that it is the basis of all knowledge and certainty is fallacious.
By which is meant the non-R.E.M, non-dreaming stages
