Nature has two inter-related meanings in philosophy and natural philosophy. On the one hand, it means the set of all things which are natural, or subject to the normal working of the laws of nature. On the other hand, it means the essential properties and causes of individual things.

Physis is a Greek philosophical, theological, and scientific term, usually translated into English—according to its Latin translation "natura"—as "nature". 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". 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. Further, since Aristotle the physical has been juxtaposed to the metaphysical.