Again on Descartes' Method

Descartes method of doubting exposed in the Mediations worked in the following way. His intention was to doubt every proposition he was able to. For that he used two conjectures: the conjecture of the dream, and the conjecture of the evil demon. All his knowledge can be just a dream or all his knowledge can be a big lie because some evil demon is devoted to deceive him. Descartes’s point with these two conjectures was to show their bizarreness. He needed a measure of certainty that goes beyond everything, even reaching the incredible and the bizarre.
Going on these two bizarre conjectures he concludes that he is able to doubt absolutely everything, with just one exception: Cogito, ergo sum (I think, therefore I am). He can doubt everything but he is not able to doubt that he thinks. To doubt is to think and to exist.
He sees himself as a thing that thinks, that is a thing that doubts, understands, affirms, denies, etc. When someone doubts its own existence he must exist in the first place to be able to doubt.
He goes further and searches for certainty of a truth. The general rule he establishes is that all things he is able to perceive clearly and distinctly are true. These elements of clarity and distinctness are taken from his single and indubitable truth; they guaranteed its certainty. The certainty of his existence is an essential characteristic of certain truth.
This criterion of clarity and distinction helps Descartes to bring back much of what he was doubting at the beginning. This is like geometry: you have a theorem and you can demonstrate it by deducing it from axioms by using rules logic. I think, therefore I am (is his axiom) and everything that I perceive clearly and distinctly is certain (is his rule of logic). Based on these he discovers that God exists, and that God would not deceive his thinking mind in believing that the external world with the objects in it is false if this world would not exist. For Descartes there are, beyond God, two separate and distinct substances (the material substance that occupy space, and the mind that thinks). These two are independent of each other.

blog comments powered by Disqus