Descartes’ Method: A Unified Approach to Knowledge
Descartes’ Method: Unity and Simplicity of Reason
The primary concern of Descartes is the discovery and justification of a new method. This method, founded on the unity and simplicity of reason, applies to all fields of knowledge. It is a method for invention and discovery, open to all who possess reason and common sense. While the mathematical method serves as a good example, Descartes does not adopt it blindly. Instead, he seeks to justify its prior value.
The universal method proposed by Descartes consists of four simple and certain rules:
- Never accept anything as true without evident knowledge of its truth.
- Divide each difficulty into as many parts as possible and as are required for its resolution.
- Conduct thoughts in an orderly manner, beginning with the simplest and easiest to know, and ascending to the more complex.
- Make enumerations and reviews so complete as to be assured of omitting nothing.
Methodic Doubt and the Thinking Subject
Descartes searches for a truth that can be believed in itself, from which all others can be deductively derived. Applying the method’s emphasis on clarity and precision, he seeks a firm foundation, a truth beyond all doubt. This leads to methodical doubt: provisionally considering as false everything that is possible to doubt. This is not to say that nothing is knowable, but rather it is the first step in searching for truth without mixing knowledge with misjudgment. Doubt is absolute and universal, extending to all knowledge, but it is not skeptical or nihilistic, because it cannot deny that knowledge exists. Only after doubt emerges truth.
“I doubt everything, but what is not possible to doubt is that I doubt, that I think. I am a subject because it is certainly true that I think. Even if I doubt what I think, I undoubtedly exist.” This is the meaning of the famous phrase, “I think, therefore I am” (Cogito, ergo sum). This is the first evidence, the first clear and distinct idea. Upon this certainty, which is innate and necessary, all other knowledge must be established.
The Ideas and Their Classes
The first truth is that there is a subject that thinks. To open up to the world, the subject has only undoubted ideas. Every idea has a subjective, mental reality. Descartes distinguishes three classes of ideas:
- Innate: Part of the thinking subject and therefore do not come from experience or are built from other ideas.
- Adventitious: Seem to come from experience.
- Factitious: Constructed from other ideas.
The Existence of God and the World
The proof of God’s existence stems from the innate idea of infinity. “I, a finite being, have the idea of infinity. This idea cannot come from a finite being, like myself, but from an infinite being. Therefore, this infinite being must exist independently of me.” From this, Descartes deduces the infinite substance, whose attribute is infinity.
To prove the existence of the world outside the subject, Descartes turns to God, who has just been shown to exist, as a guarantee. The ideas in me of the outside world come from the world that is really out there, because God cannot allow me to be fooled into believing the world exists. This is the deduction of corporeal substance, whose attribute is extension.
The Problem of Man and Freedom
Man, unlike animals, possesses a rational soul, which is closely related to the body. However, body and soul are distinct substances with different properties. While the soul (reason) is characterized by thinking, the body is an extended reality, a machine that, like animals, is subject to the mechanisms of the physical world. This raises a serious problem in explaining the communication between the two substances.
According to Descartes, this relationship is established through the pineal gland, where the soul has its seat. The soul is influenced by passions, involuntary actions caused by the body, which can prevent man from acting rationally. The progressive dominance of reason allows man to become master of his will and make use of freedom. Freedom is not choosing arbitrarily between several possible actions, but choosing and acting according to reason.