Cartesian Philosophy: Reason, Method, and Metaphysics
Thoughts, Ideas, and the Pursuit of Knowledge
Since knowledge is always knowledge of ideas, the fundamental epistemological problem in modern philosophy is determining the truth of ideas. Descartes examines the types of ideas to escape solipsism and demonstrate the existence of a perfect external reality, which is God. The text refers to God as a perfect being, whose existence is the cause of the idea of perfection. In Cartesian philosophy, God’s existence is demonstrated; He is one of the three “substances,” and His essential attribute is perfection.
1. Contexts:
- The consolidation of absolutism in the 17th century led to the creation of national states.
- Religious strife between Catholics and Protestants in the Thirty Years’ War, ending with the Peace of Westphalia, resulted in the spread of religious tolerance.
- Counter-Reformation figures emerged, such as St. Teresa of Avila, St. John of the Cross, the Society of Jesus, and St. Ignatius of Loyola, along with the Council of Trent.
- Capitalism favored trade expansion, contributing to the emergence of large trading companies and early stock markets.
- Remarkable progress in science, based on observation and experimentation, promoted capitalism.
- New and refined measuring instruments (like the thermometer) were invented in physics.
- Great physicists included Pascal and Torricelli.
- Mathematics thrived with Descartes and Leibniz.
- Astronomy saw advancements with Brahe, Kepler, and Newton.
- In philosophy, the focus shifted from explaining the “why” to determining the “how.” Philosophy placed its confidence in reason; it was the century of method.
2. The Method:
Method, Evidence, Rule, Synthesis, Unity of Reason
Descartes defines the method as understanding certain rules and an easy method to avoid falsehood, minimize mental effort, and gradually increase knowledge to reach true understanding. The method aims to: advance the acquisition of truth and form the basis of science. There are four rules:
- Evidence: Establishes evidence as a criterion of truth. A truth is what presents itself to the mind with clarity and distinction. Understanding is achieved through intuition, capturing the simplest elements. Evidence is an intellectual intuition; it admits degrees and rejects probability. Truth is intuited.
- Analysis: Decomposing a complex idea into its simplest elements. It goes from the unknown to the known, leading to simple natures and understanding complex proportions by seeing their dependence on simpler ones.
- Composition: Establishing a logical order in inference, from the simple to the complex, starting with the simplest natures.
- Review: Verification and review of the entire process to ensure nothing is omitted.
4. Rationalism vs. Empiricism:
Rationalism
- Reason is the only source of knowledge.
- Innate ideas are truths provided by reason.
- Affirms metaphysical concepts: substance, soul, essence, God.
- Clarity and distinction in reason are criteria for truth.
- Knowledge is universal and necessary.
- Mathematics is the model of science.
- Deductive method is used.
Empiricism
- Experience is the only source of knowledge.
- There are no innate ideas; all knowledge is acquired.
- Rejects metaphysical concepts: substance, soul, essence, God.
- Experience is the criterion for truth.
- Only contingent knowledge is possible.
- Physics is the model of science.
- Inductive method is used.
Metaphysics and Methodical Doubt:
Substance, First Truth, God, Soul, Metaphysics, Methodical Doubt, Second Truth
We need to find a self-evident truth to build a philosophical system. To do so, Descartes decides to use doubt to find something that resists it. This process is:
- Methodological: A procedure to find a principle that can serve as a foundation for metaphysics.
- Theoretical: Only in terms of philosophical reflection, not religion or morals.
- Universal: All questions, excluding religious knowledge and practice.
Types of Doubt
- Doubt of the Senses: Senses sometimes deceive us, so we should not rely on them. This is confirmed by the inability to distinguish dream from waking.
- Doubt of Reasoning: We can make mistakes while reasoning, even in mathematical proofs.
- Doubt of Intelligence: Perhaps a God systematically deceives us, making us believe we are right when we are wrong. Descartes rejects this, positing that a good God cannot deceive. He replaces this with the hypothesis of an evil genius that makes us err.
- Doubt of Reality: Although senses may give false information, we consider things real. Descartes argues that it is easy to doubt the reality of things.
Key Concepts:
- Images: Come from experience and cannot justify certain knowledge.
- Innate Ideas: Knowledge independent of experience.
- Soul: Thinking substance.
- Cogito, ergo sum: The first truth, arrived at after applying methodical doubt. It is a true innate idea, clear and distinct, from which to reconstruct knowledge.
- God: Infinite substance.
- Doubt: A method to reconstruct knowledge on firm pillars.
- Experience: Provides confused and doubtful knowledge about reality.
- Physics: Cartesian physics is mechanistic, using matter and motion as key elements.
- Malignant Genius: Hypothesis for systematic doubt.
- Essence: The attribute of a substance.
- Evidence: The object of an intuition of reason.
- Intelligible Truth: Can be known through reason.
- Me: Thinking substance.