solipsism
n. the philosophical position that one can be sure of the existence of nothing outside the self, as other people and things may be mere figments of one’s own consciousness. Although psychologically unacceptable, such a position is notoriously difficult to refute, either logically or empirically. The question posed by solipsism has been put in various ways, but all arise from the fact that one’s experience of one’s own consciousness and identity is direct and unique, so that one is cut off from the same kind of experience of other minds and the things of the world. See Cartesian self; egocentric predicament. —solipsist
n.
—solipsistic
adj.