(n.) That department of the science of metaphysics which investigates and explains the nature and essential properties and relations of all beings, as such, or the principles and causes of being.

aesthetics axiology casuistry cosmology epistemology ethics existentialism first philosophy gnosiology logic mental philosophy metaphysics moral philosophy phenomenology philosophastry philosophic doctrine philosophic system philosophic theory philosophical inquiry philosophical speculation philosophy school of philosophy school of thought science of being sophistry theory of beauty theory of knowledge value theory