René Descartes: Rationalism and the Cartesian Method

Reason and Methods in Cartesian Philosophy

René Descartes is considered the father of modern philosophy and rationalism, the first modern philosophical current. Modern philosophy is defined by two main features:

• Connection to empirical sciences: Physics and astronomy emerged from the Copernican revolution.
• Mathematical application: Philosophers sought to apply the effectiveness of empirical sciences to philosophy by utilizing the mathematical method.

Characteristics of Rationalism

Rationalism posits that reason is the primary source of knowledge. It underestimates the senses and considers reason to be self-sufficient. Modern rationalism is diametrically opposed to British empiricism (Locke and Hume), which rejects the concept of innate ideas—ideas that are born with us and exist in our minds from the start.

Characteristics of Reason

According to Descartes, reason possesses the following characteristics:

• Autosufficiency: It is sufficient by itself.
• Autonomous: It is not limited by culture, tradition, or faith; it must be free.
• Universal: Reason is the same for all human beings; those who use it correctly draw the same conclusions.
• Unique: The same reason applies both theoretically and operationally.

Therefore, while there are different sciences, there is only one universal science based on mathematical objects.

Operations of Reason

Reason functions through two primary operations:

• Intuition: An intellectual view that leaves no room for doubt. The object of intuition is simple ideas, perceived directly without error.
• Deduction: The process of discovering the connections between simple ideas.

The Cartesian Method

If reason is self-sufficient and universal, why do humans hold different opinions? The answer lies in the misuse of reason. Factors such as prejudice, education, impatience, and passion influence our judgment. To ensure we use reason correctly, Descartes proposes an analytic-synthetic method consisting of four rules:

1. Evidence: Do not accept anything as true unless it is known with certainty to be clear and distinct, leaving no room for doubt.
2. Analysis: Decompose complex ideas into simple ones to intuit them clearly.
3. Synthesis: Recompose simple ideas through deductive links.
4. Enumeration: Review the entire process to ensure nothing has been omitted and to gain a total insight into the process.

The central part of the method relies on the analytic-synthetic approach, where analysis is associated with intuition and synthesis is associated with deduction.