Descartes’ Cartesian Method: Rules and Principles

Posted on Jan 30, 2025 in Philosophy and ethics

The Cartesian Method

1. Introduction

Having rejected Scholastic and Aristotelian philosophy, Descartes proposed mathematics as a method of certainty for the human spirit. In his *Discourse on Method*, he presents an autobiography where he explains how he leads his reason to obtain truth. He defines the procedure as that set of certain and easy rules to move us forward in knowledge, without creating confusion between true and false and without fatigue.

2. Purpose of the Method

The purpose of the method is to guide reason to avoid mistakes and advance knowledge.

3. Origins of the Method

The School of Padua proposed the hypothetical-deductive method. Descartes rejects the experiment, drawing on analysis, logic, Euclidean geometry, and algebra.

Traits of the Cartesian Method

  • Reason as an instrument of knowledge.
  • The method requires guiding thoughts to avoid unnecessary efforts and mistakes.
  • Mathematicism: Mathematics is the perfect model to follow. The goal is to turn Descartes’ philosophical thought into mathematics. All sciences need to be demonstrated through mathematical formulas.
  • Simplicity: Two operations are key:
    • Intuition, which involves a grasp of the truth through understanding.
    • Deduction, which is a continuous intuition.

Rules of the Method

The method is based on a truism, from which different truths are reached. Descartes sets four rules (the first refers to intuition, and the other three to deduction). He uses two operations:

  • Analysis: 1st and 2nd rules
  • Synthesis: 3rd and 4th rules

Rules

  1. Evidence: Only accept as true that which is obvious. It is an act that immediately captures an idea. It is divided into two parts:
    • Clarity: When an object is clearly distinguishable from another. However, clarity is not sufficient alone (an idea can be clear and confused at the same time).
    • Distinction: That which is accurate and different from everything else. An idea is distinct when its parts are different from each other.
    Requirements to achieve the obvious:
    • Do not judge based on preconceptions.
    • Judge only what appears evident.
    • Do not include more than what appears to be clear and distinct (criterion of circumspection).
    Two vices to avoid:
    • Precipitation: Taking a confused idea as true.
    • Prevention: Refusing to accept the obvious due to insights gained in childhood.
    Conclusion: An idea is clear when it is separate and not confused with others, and it is distinct when its parts are separated. The distinction applies to both ideas and things (it’s an epistemological and ontological approach).
  2. Analysis: Reduce a problem to its simplest aspects (simple natures) known by intuition as clear and distinct. These natures are of three types:
    • Intellectual (thinking)
    • Material (motion)
    • Common (existence)
    Strictly speaking, the method begins with this rule by dividing the difficulties.
  3. Synthesis: Drive thoughts from the simplest to the most complex. Deduction is made, which consists of stringing ideas in a succession of intuitions.
  4. Enumeration: Make counts and reviews to verify that nothing is omitted, to prevent mistakes. Descartes proposes the example of a chain, where if one link fails, the entire chain fails.