This book deals with Metaphysics as a branch of philosophy which studies the most general categories, concepts and descriptions of ourselves and the world; causality, substance, ontology, time, and reality. Metaphysical questions can ask whether our actions are subject to causality, which gives rise to the problem of free will, and the question of whether our mental experiences involve a separate substance from body is a major issue in the philosophy of mind. Although metaphysics dates back to the ancient Greeks, the rise of science led to attempts by philosophers to limit the claims of metaphysics, and earlier in the last century scientifically minded philosophers such as the logical positivists claimed that metaphysical assertions were meaningless. In modern times the term used for the interpretation of Metaphysics is widely miscomprehended. The misunderstanding of the subject of Metaphysics extends to the mystical and esoteric feelings of the oriental religions and conceptions of therapeutic methods.