[From Theosophical Encyclopedia; here slightly revised in content and adapted to Theosophy Forward style.]
A branch of philosophy that includes cosmology and ontology. The term is derived from an untitled work by Aristotle called merely meta ta physica, i.e. “The book after the Physics.” In it Aristotle claimed to discuss Being in an abstract sense. Since his time, the term has been extended to cover cosmology as well as what types of things may be reliably said to exist, i.e. ontology.
Ontology usually discusses nonphysical things, such as minds, angels, and God. Cosmology usually involves theories of creation as well as the nature of the created universe and the evolution of life forms on Earth. Obviously, cosmological theories rely on astronomy and physics for information about the universe, but usually go beyond them and include arguments for the existence of nonphysical things, such as minds and God. Because our knowledge of the physical universe has changed considerably since Greek and medieval times, theories propounded by those early philosophers are now studied only in the history of Western philosophy. However, one of the on-going philosophical debates in ontology is whether one can defend the existence of a non-physical mind separate from the body and, therefore, likely to survive the body’s death. Textbooks in philosophy also usually include arguments for the existence of God. Theosophical metaphysics affirms the idea of the survival of the human personality after bodily death — as well as the existence of such nonphysical entities as nature spirits (sometimes called fairies), angels, and gods (conceived as a hierarchy of superior beings rather than a single Being). The justification of that claim is usually based on clairvoyance. The term metaphysics also sometimes includes such things as astrology, which both philosophical metaphysicians and some Theosophists deny.