Solipsism is the belief that one can only be certain that their own mind exists, and that all ideas outside one’s own mind are suspect. While it’s impossible to prove that anything beyond one’s own mind actually exists, no sane person will live as a solipsist. We all act as if others exist, and base our lives on interactions with them.
Solipsism is the idea that only one's own mind is certain to exist. Very few people are sincere solipsists. Instead, solipsism is generally used as an argumentation tool. For example, one might ask how another knows that something is true, to which a scoffing reply might be "How does anyone know that anything is true?
