Descartes’ Methodic Doubt

Due to the remarkable achievements made in the natural sciences since the Renaissance period, seventeenth-century philosophy regarded the mechanistic view of nature as absolute truth, and tried not to contradict it. Rationalism tried to provide a foundation for the mechanistic view of nature from a fundamental standpoint. Its representative proponent was René Descartes (1596-1650). Descartes considered the mathematical method to be the only true method; thus, as in mathematics, he first looked for an intuitive truth that was obvious to everyone, and then based upon that, he sought to develop a new, certain truth deductively.

Thus, there arose the question of how one could seek an intuitive truth that could become the starting point of philosophy. Descartes’ method was to doubt as much as he could in order to pursue an absolutely reliable truth, which could then become the principle for all knowledge. Even though he doubted everything, however, he noticed that the fact that he, who doubted, existed could not be doubted. He expressed this in his famous proposition, “I think, therefore I am” (cogito ergo sum). Next, he asked why that proposition was certain without any proof, and he answered that it was because that proposition was clear and distinct. From that point he derived the general rule that “things we conceive very clearly and very distinctly are all true.”

Cartesian doubt is not for the sake of doubt, but for the sake of discovering truth. It is called methodic doubt. Descartes tried to obtain sure knowledge by following the mathematical method, with which one starts with axioms that can be intuited clearly and distinctly, and then goes on to prove various propositions.