1. Metaphysics: the branch of philosophy that deals with the nature of reality, existence, and the relationship between mind and matter. 2. Epistemology: the branch of philosophy that deals with the nature of knowledge, belief, and justification. 3. Ethics: the branch of philosophy that deals with moral principles, values, and the concept of right and wrong. 4. Aesthetics: the branch of philosophy that deals with the nature of beauty, art, and taste.