Descartes’ Discourse: Metaphysics, Doubt, and the Cogito

Posted on Nov 28, 2024 in Philosophy and ethics

Analysis of Descartes (Part 4 of the Discourse on Method)

1. Concept of Metaphysics

The text centers on proving the existence of God and the human soul, questioning fundamental concepts (Descartes).

3. Doubt

This section explores the mind of modern man, leading to a foundational re-evaluation after dismantling existing views. Cartesian philosophy re-establishes knowledge foundations through two phases:

  • Phase destructive: Universal, methodical doubt demolishes the convictions and principles of contemporary culture and science.
  • Phase constructive: The Cogito aims to establish knowledge on new bases.

Descartes establishes a method (Meta-Odos) to address these vital concerns.

3.1. Methodical Doubt

Methodical doubt eradicates falsehoods and uncovers truth. Descartes rejects:

  • The existing world of knowledge.
  • Knowledge from books, including scholastic philosophy and intellectual or experiential knowledge.

He adopts a radical solution: suppressing all opinions to forge his own path, finding no sure principle. This methodical doubt, while not permanent, seeks an unquestionable principle. It is the foundation of his philosophy.

Doubt’s process is based on:

  • Spurious senses: Mediators between reality and thought, unreliable knowledge sources.
  • Dreams: The difficulty of distinguishing between waking and sleeping leads to a provisional rejection of the external world’s existence.
  • An evil genius: Even in mathematics, certainty is questioned. The possibility of deception is considered.

Descartes continues until finding a firm and true point.

4. The Method

The method, Descartes’ constant pursuit, is the only path to truth. As early as the Discourse on Method and Meditations, reason is established as the sole guide. Descartes discovers subjectivity.

His unified conception of the method is based on:

  • Thesis of the unity of science: All sciences are aspects of human wisdom.
  • Unity of Reason: It is the same in all men.
  • The method must be unique: Reason requires universal rules, achievable only through a single method.

Descartes’ method deviates from scholasticism, emphasizing the method’s importance regardless of subject. He seeks to underpin modern philosophy with Mathesis Universalis (Universal Mathematics). This method, the ratio method, must be unique and universally valid.

Reason involves two activities:

  • Intuition: Effortless grasp of clear and distinct concepts “simple natures” like extension and movement). Extension and thought are the most important innate ideas.
  • Deduction: Deriving composite ideas from others. Deduction is a chain of intuitions.

Clear and distinct ideas are the criterion of certainty. The method is a set of rules preventing falsehoods and leading to truth.

The method’s four precepts are:

  1. Rule of Evidence: Accept only what is evidently true.
  2. Rule of analysis: Divide difficulties into parts to find simple natures.
  3. Regulation of synthesis: Proceed from simple to complex ideas.
  4. Rule of enumeration: Check and review the process.

Descartes is inspired by Euclid and the Paduan School.

5. Discovery of the First Truth: The Cogito

Descartes’ doubt leads to the realization that thinking is undeniable: Cogito, ergo sum, je pense, donc je suis. Ego sum, ergo I exist, je suis, j’existe.

This is the starting point, the essence of thinking, from which other things emerge. It is the foundation of modern philosophy.

6. The Treatment of Reality

Reality is extended in three dimensions:

  • Man (Res Cogitans): Anthropological reality.
  • God (Res Infinita): Theological reality.
  • The world (Res Extensa): Physical reality.

Substance is a synonym for”thing” existing independently. Only God is a substance; His creatures require Him to exist. There are two types of substances: God (infinite) and finite substances (souls and bodies).

6.1. I Think

The primary concept is”I think” which is indubitable. Ideas have two aspects: subjective (formal reality, which cannot be false) and objective (images of things, which may be false). Ideas are classified as innate, adventitious, or fictitious.

6.2. The Infinite Substance, God

Descartes’ need for extrasubjective reality leads to God’s mediation. Demonstrations of God’s existence include:

  • 1st Demo: The idea of perfect being must come from a perfect being.
  • 2nd Demo: Continuous creation requires divine intervention.
  • 3rd Demo: St. Anselm’s ontological argument.

6.3. Finite Substances: Body and Soul

Finite substances need God to exist.

  • The soul (Res Cogitans): Thought is its only attribute.
  • The body (Res Extensa): Extension is its only attribute.

Cartesian dualism is presented: Res cogitans (soul) versus res extensa (body), substances needing each other to exist.