Descartes and Hume: Reason vs. Experience

René Descartes (1596-1650)

Baroque Philosopher

Inventor of the Cartesian project, which examines the structure and functioning of reason through four steps:

• Intuition: Clear and evident self-knowledge.
• Deduction: Argumentative chain leading to a conclusion.
• Analysis: Breaking a whole into parts.
• Summary: Recomposition of the essential.

Descartes employs methodic doubt with three parts:

• The fallacy of the senses: Sensory world is uncertain.
• Inability to distinguish waking from sleep: No definitive proof of wakefulness.
• Evil spirit: Doubt even in mathematics.

Descartes' first truth: "Cogito, ergo sum" (I think, therefore I am), proving the Cogitans (mental side). Criterion of validity: Truths must be clear and distinct.

Ideas are divided into:

• Adventitious: From senses, unreliable.
• Fictitious: Imagined, not necessarily true.
• Inborn: Evident and unquestionable, passing the criterion of validity.

Descartes argues for God's existence and the material world through the ontological argument.

Anselm's Empiricism (Hume)

Sensory Experience as Knowledge

David Hume (1711-1776) posits that knowledge comes from sensations and perceptions.

Distinguishes between:

• Truths of fact: Experimental world.
• Truths of reason: Relationships between ideas (e.g., mathematics).

Hume's criterion of validity: Ideas must come from experience, otherwise they are fiction (e.g., God, I).

Critiques the necessity of causal relationships, arguing that future experiences are uncertain.