Descartes presents the Cogito as a means of proving his existence in the meditations. Following his three stages of doubt, Descartes has found himself in hyperbolic doubt, unable to find a single certain truth to build his beliefs upon, until he performs the Cogito in the second meditation. He uses this to argue for his necessary existence as a ‘thinking thing’, before going on to establish the mind/body distinction. I am arguing for Descartes’ success in proving his existence, by considering his methods and some objections, before discussing some of my own opinions on why I believe Descartes was successful.
Descartes begins the first meditation by doubting everything he possibly can. The first wave of doubt sees him withholding assent about the senses. He claims that if they have deceived him before, they are likely to do so again so he must not trust them. Descartes anticipates the response that suggests he cannot doubt that which is obvious to him, such as his own body, so he considers the possibility of him dreaming. He claims that he cannot distinguish dreaming from being awake. It appears to him that he is awake and not dreaming, yet it is possible that he is dreaming about sitting in front of the fire.
However, he has still not doubted everything, as there are some things that still apply in dreams, such as mathematics and geometry. Even in dreams, two plus three will still equal five, and a square will always have four sides. The third wave of doubt allows Descartes to doubt whether this is the case. He contemplates whether there is an all powerful, evil demon deceiving him and if there is the slightest possibility of this, Descartes must disregard all previous beliefs. There is a chance that the demon is misleading him to believe that a quadrilateral has four sides, when in fact it has seven. Descartes has now reached the point where he believes everything can be doubted.
At the beginning of Meditation Two, Descartes is unsure of how to escape the doubt he finds himself drowning in as a result of the previous day’s doubts. He starts by considering whether he can deceive himself. It appears that he can doubt his senses, whether he is dreaming and whether 2+3=5, but he cannot doubt the fact that he is thinking. Although his thoughts may be deceived, he is persuaded that he exists, merely by having thoughts at all. He has thus presented the Cogito as an argument for his existence.
Descartes claims that even though the demon may be deceiving him, he must exist in order to be deceived. If he is doubting, he is thinking, and so long as he thinks, he is something, and that something exists. Every time Descartes expresses or conceives the words ‘ego sum, ego existo’, it is necessarily true.
Thus far, Descartes has proved that he exists but has not discussed at length what it is that exists. He is unable to concede that his body exists, as the three waves of doubt from the first meditation still apply. The only thing at this point Descartes is able to claim, is that he is something, and that something is a thinking thing.
However, Descartes has been criticised for claiming too much without having accounted for it in the Cogito. He has only managed to show that there is thinking going on, as opposed to a thing having those thoughts. At the moment, Descartes is only allowed to say that there are thoughts happening at the time they are being thought, so this suggests that he should not refer to himself as a ‘thinking thing’, as he has not proved that those thoughts belong to him.
The Lichtenberg Objection takes a similar angle by arguing that the only thing proven by the Cogito is that there is thinking happening. It suggests that the thoughts do not require a thinker, in a similar way that the happening of rain does not require a ‘rainer’. I take this to be an ineffective criticism as the analogy assumes that the essence of rain is the same as that of thoughts. However, it seems that thoughts are similar in essence to that of walking. Walking requires a walker and thoughts require a thinker.
Descartes starts the sixth meditation off by establishing his body and the material world. To do this, he explains the difference between imagination and intellect, and how imagination requires more effort. Imagination is not an essential part of the ‘thinking thing’ that he considers himself to be, so if he possessed a body, it would explain the existence of imagination. He concludes that it is likely that he has a body which experiences the external world.
He then returns to the Cogito to prove that not only is he a thinking thing, but that he has a mind which is separate to his body. As a radical dualist, he believes that the mind possesses completely different properties to the mind, which in turn, leads to him to believe that they cannot be one and the same thing. The body is a divisible, unessential and extended substance whereas the mind is certain, essential and indivisible.
With various methods, Descartes has tried to establish that not only does his body exist, but his mind does too. The Cogito has tried to prove that he is a ‘thinking thing’ which was then developed upon to prove the existence of a body and mind. Although I consider the Cogito proving him to be a ‘Res Cogitans’ a success, the methods in which he confirms the existence of a body fall short and opens itself up to criticism. Thus, I believe Descartes to be successful in proving his existence as a thinking thing only.