.... is the philosophical idea that only one's own mind is sure to exist.
The term comes from the Latin solus (alone) and ipse (self). Solipsism is an epistemological or ontological position that knowledge of anything outside one's own specific mind is unjustified . The external world and other minds cannot be known and might not exist. In the history of philosophy, solipsism has served as a skeptical hypothesis (dankie Liza!)