Solipsism ( ) is the view that a person has no reason to believe anything exists except their own mind. It is a philosophical position that first appeared in ancient philosophy. It mainly means to reject or doubt that other people exist. "" and "" are the Latin words for "alone" and "self", which is where the word "solipsism" comes from. Some kinds of solipsism say that everything outside a person's own mind (including other people) is only imaginary. Other kinds of solipsism instead say that nothing outside a person's own mind is certain.