Modern Philosophy: Rationalism and Empiricism (Descartes and Hume)
What this domain tests
The Modern block tests the rationalist-empiricist contrast through two central authors. For Descartes you must explain methodic doubt, the cogito, clear and distinct ideas, the proofs of God and mind-body dualism. For Hume you must explain the impression-idea distinction, the copy principle, the analysis of causation, the problem of induction, the bundle theory of the self and the is-ought gap.
Core rules and concepts
- Descartes: doubt is methodological, not ordinary skepticism. The cogito is performed, not inferred from a syllogism; its certainty rests on the immediate presence of the thinking act. Clear and distinct perception is the criterion of truth, and God's veracity guarantees that what is clearly perceived is true. Mind and body are really distinct substances, yet interact.
- Hume: all simple ideas are copied from impressions; where no impression can be found, the idea is suspect. Relations of ideas are necessary but concern only concepts; matters of fact are contingent and rest on experience. Causation is not observed as a necessary tie: we see constant conjunction, contiguity and succession, and the mind acquires a custom or habit of expectation. The self is a bundle of perceptions, not a substance.
Worked example
Explain why one billiard ball moves another. A Humean analysis proceeds: the first ball's motion is an impression; the second ball's motion is a distinct impression; we observe contiguity and constant conjunction across cases; we never perceive a power or necessary connection. The idea of causal necessity is therefore generated by custom, not copied from an impression. A strong answer adds that Hume does not deny that we make causal judgments; he explains their origin and limits. It also separates the psychological explanation (habit) from the epistemological point (induction cannot be justified non-circularly).
Traps
Do not present the cogito as the premise 'whatever thinks exists' followed by a conclusion. Do not call Descartes a skeptic in the final sense. Do not treat Hume as denying causation in practice or as a dogmatic skeptic; his position is naturalistic. Do not confuse relations of ideas with matters of fact. Avoid summarizing the Meditations without explaining the order of reasons.