Solipsism is sometimes expressed as the view that "I am the only mind which exists," or "My mental states are the only mental states." However, the sole survivor of a nuclear holocaust might truly come to believe in either of these propositions without thereby being a solipsist. Solipsism is therefore more properly regarded as the doctrine that, in principle, "existence" means for me my existence and that of my mental states. Existence is everything that I experience -- physical objects, other people, events and processes -- anything that would commonly be regarded as a constituent of the space and time in which I coexist with others and is necessarily construed by me as part of the content of my consciousness. For the solipsist, it is not merely the case that he believes that his thoughts, experiences, and emotions are, as a matter of contingent fact, the only thoughts, experiences, and emotions. Rather, the solipsist can attach no meaning to the supposition that there could be thoughts, experiences, and emotions other than his own. In short, the true solipsist understands the word "pain," for example, to mean "my pain." He cannot accordingly conceive how this word is to be applied in any sense other than this exclusively egocentric one