# Rene Descartes’ Understanding of Method

June 27, 2021Descartes was keenly interested in whether there was a certain universal principle that would fundamentally grasp all other fields of knowledge from mathematical precision: during his training at the Jesuit school, he perceived that certainty in mathematics was not found in any of the other fields of knowledge.

He explains his doubts about other fields of knowledge in his book Conversation on Method. He states that he could not find real certainty in any of the fields of literature, poetry, history, philosophy, and theology, and that much of the knowledge in these fields was open to discussion and doubtful. It is not clear what the method applied in these areas is. For this reason, since it is the main carrier of all branches of science, he pursues philosophical certainty and is convinced that it is necessary to follow the method or methods that give certainty to mathematics in order to reach certain and solid knowledge in philosophy. Precision in mathematics is the best example of mental precision.

He thinks that philosophical certainty must also be captured rationally. Because, during his travels in Europe, he saw that people’s sensory-based experiences, beliefs and opinions are different from each other and it does not seem possible to reconcile them. For this reason, it does not consider it possible to obtain philosophical certainty through experiential, sensory means. Only the alternative of rational certainty remains. In this case, he has to find out the universal truth only from his own reason, based on his own power of reason. In this way, he thinks what can be the method or methods based on pure reason. The example is opposite; The reason why mathematics, which is the best example of mental precision, is a precise, clear and clear branch of knowledge, undoubtedly stems from the method or methods it applies. So what are they? It is seen that deduction and intuition methods are used in mathematics. In that case, it would be appropriate to apply these methods in philosophy in order to reach a universal truth that includes rational certainty.

Descartes thought that in order to reach certain and solid knowledge in philosophy, it is necessary to follow the methods that bring certainty to mathematics.

Mathematics as a Method

Descartes was a great mathematician as well as a great philosopher. He saw the mathematical method as an indispensable element in order to present his philosophy clearly and firmly.

In his Conversation on Method, he stated the following about mathematics: “Because of the precision and self-evidence of its proofs, I enjoyed mathematics more than anything else, but I could not yet see its true use very well; However, considering that it was useful for the mechanical arts, I was surprised that a higher structure had not been built on such solid and unshakable foundations.”

In this respect, Descartes left traditional methods aside and thought that the mathematical method should be applied to philosophy in order to make philosophy an exact science by trying to do what has not been done before.

Descartes saw traditional logic as a method of “explaining what is known to others rather than teaching something new”, incapable of discovering the unknown. Moreover, according to Descartes, traditional logic contains many correct and useful rules, as well as many harmful and unnecessary rules. As a result of this, Descartes set aside the rules that make up traditional logic and decided to strictly adhere to the following four rules in his own thinking process:

“Not to accept as true anything that I do not clearly know to be true; that is, to carefully avoid making hasty judgments and being stuck in prejudices, and to include in my judgments only what I grasp so clearly and distinctly that they cannot be doubted.”

“In order to better analyze the difficulties that I will examine, divide each into as many parts as possible and as necessary”

“To run my thoughts in an order, starting with the simplest and easiest things to understand—assuming there is even a sequence, even between things that are not naturally successive—to gradually ascend to the knowledge of the most complex things, just as step by step down a ladder.”

“Do thorough counts and general checks on all sides to make sure I’m not missing anything”

As can be seen, the method that Descartes reduced to these four rules can be seen as an application of the analysis and synthesis methods used by mathematicians in their fields, in the field of philosophy. Accordingly, complex and obscure propositions are analyzed and reduced step by step to simpler propositions and then to basic propositions. Then, starting from these simplest propositions, the information at hand is synthesized and new information is increased step by step.

According to Descartes, mathematics is a method in its own right, independent of the mathematical objects it deals with (for example, geometric shapes and numbers). Therefore, this is not only specific to the objects of mathematics, but universally to all knowledge.