Philosophy studies the fundamental nature of existence, of man, and of man’s relationship to existence. … In the realm of cognition, the special sciences are the trees, but philosophy is the soil which makes the forest possible.
—Ayn Rand, Philosophy, Who Needs It (p. 2)
- Metaphysics (the theory of reality).
- Epistemology (the theory of knowledge)
- Ethics (the theory of moral values)
- Politics (the theory of legal rights and government)
- Aesthetics (the theory of the nature of art)