The term originated in ancient Greek philosophy, and was later used in Christian theology and Western philosophy. In pre-Socratic usage, physis was contrasted with νόμος, nomos, "law, human convention".[1] Another opposition, particularly well-known from the works of Aristotle, is that of physis and techne – in this case, what is produced and what is artificial are distinguished from beings that arise spontaneously from their own essence, as do agents such as humans.[2] Further, since Aristotle the physical (the subject matter of physics, properly τὰ φυσικά "natural things") has been juxtaposed to the metaphysical.