- Sub-branch of metaphysics - Core issues: - The mind-body problem - The relationship between minds / mental processes and bodily states / processes. - Descartes (1641) the first to formulate the mind-body problem as it exists today. Proposed a substance dualism: the mind is an independently existing substance. - Bodies are objects with mass and location in space and time. But what is the shape, size, or location of your mind / thoughts? - The hard problem of consciousness - The nature of mental states