Solipsism

‘Solipsism’ (from the Latin solus ipse – oneself alone) is the doctrine that only oneself exists. This formulation covers two doctrines, each of which has been called solipsism, namely (1) that one is the only self, the only centre of consciousness, and, more radically, (2) that nothing at all exists apart from one’s own mind and mental states. These are not always distinguished from corresponding epistemic forms: for all we know, (1) or (2) might be true.

A more recent coinage is ‘methodological solipsism’, which has a quite different meaning: that the content of an individual’s thoughts is fully determined by facts about them, and is independent of facts about their environment.