Descartes' the Cogito

"I think" or "the cogito", is the first certainty of Descartes, the first step to knowledge, the argument that lays the foundation for the philosopher's rationalism, and a central concept of his masterpiece. Reflecting on his certainty, he says that, in his first knowledge, there is only the clear, distinct perception of his affirmation (Descartes, Cottingham and Williams, pp. 113).

He continues by arguing in favor of the general principle, a thought so distinct and clear that cannot be doubted. The cogito, and the path the philosopher follows in order to arrive at it, lays the foundations for his dualism: does he exist? What does stating one's existence or thinking means?

Descartes claims to be a thinking thing, a substance, and, by this, many philosophers thought that he meant to affirm his continuity, his persistence from one moment and thought to another. These philosophers argued that, as long as the existence of the evil demon is possible, there is no way of knowing, of proving the persistence of anything in time as unity.

The only thing that is certain is the succession of his thoughts. The philosopher replied to this objection in ‘Objections and Replies’, the Meditations' Appendix, saying that the existence of thoughts requires the existence of a thinker. He considers this claim distinct and clear, therefore a certitude, but whether he is right or wrong depends on the meaning associated with the term ‘thinker’.

If he uses this term to refer to subjects that persist over time, then this is not obvious, it can be denied. The evil demon could simply create false thoughts, like that regarding the existence of a thinker, of a substance, and, if that were the case, how could the philosopher know it?

But Descartes could be using the term "thinker" with reference to a thought's momentary subject, implying that, in order for a thought to come into existence, something or someone must think it.

It seems justified to believe that the author cares more about the existence of the thinker than about persistence, but, if that is the case, one cannot help but wonder if momentary existence is enough to support the philosopher's later arguments.

It is difficult to perceive how someone who does not exist over time could ever acquire further knowledge beyond the moment's thoughts: "I think" and "I exist". By saying that being a thinker involves doubting, willing, imagining, he implies that these activities or actions are performed by the same subject, thus taking the subject's persistence in time for granted, and it has been already argued that he cannot know this.

But, in order to fully understand Descartes' cogito, it is important to understand what he means by clear and distinct ideas. According to him, ideas should be "open and present to the attending mind", not only clear and distinct, but also precise, separable from any other ideas, to such an extent that they contain nothing else in themselves than "what is clear" (Descartes, pp. 45).

The cogito is Descartes' first idea of this kind. Reflecting on his certainty of it, he says that in this knowledge there is only a clear and distinct perception of what he affirms (Descartes, Cottingham and Williams, pp. 113).

He continues by arguing that, at the time when it is considered, a clear and distinct thought should be believed true, should not be doubted. From arguing that a clear distinct idea can be acknowledged as true when held in mind, he goes on explaining that one cannot keep thinking of one thing in particular all the time, so one cannot continue to perceive it clearly.

Once one has turned attention away from that particular thing, one cannot be certain of it anymore, despite remembering one's certitude regarding it. This is when mistakes occur, when one can wrongly believe to perceive clearly and distinctive an idea that they do not.

Certitude regarding the distinction and clarity of what one once thought only comes with knowing that one was not deceived by an evil demon. This is a starting point from Descartes to try and show that people can be sure of the absence of the evil devil because they are aware of the existence of God, who would not deceive them or allow any evil demons to deceive them.

On one hand, in order to prove God's existence, Descartes has to rely on the things he can perceive as clear and distinct, on the only way to know anything. On the other hand, God's existence is necessary in order for him to know what he can perceive clearly and distinctly. This leads to the Cartesian circle: he uses the existence of God to support his clear and distinct ideas' doctrine, and he uses his doctrine to support God's existence.

Many will interpret his writings to say that he is certain of God's existence only because he is certain of what he clearly and distinctly perceives, and, yet, he is certain of his clear and distinct perceptions only due to his certainty of God's existence.

Descartes, however, gives his writings a different explanation. According to him, he can be certain of his clear and distinct perceptions without knowing of God existence, but at the time they are perceived. The existence of God brings about the certainty that his perceptions are true at all times (115).

Even after embracing Descartes’ replies to the objections and interpretations to his writings, one cannot help but wonder how the philosopher can be certain of his clear and distinct perceptions, even when perceiving them, as long as the possibility for him to be deceived by a demon exists.

While the famous cogito phrase remains a corner stone, a basic principle in philosophy and not only, to this day, the meanings and interpretations surrounding it cast a shadow of doubt over Descartes' reason and ideas.

Rather than clear and distinct, his ideas seem to be circling towards a type of knowledge that cannot be categorized as a priori or a posteriori, or, at least, not without taking the idea of God for granted.