Solipsism is a puzzle about meaning, not just loneliness

Solipsism is not merely the belief that one is alone. The IEP distinguishes that contingent belief from a doctrine about meaning: for the solipsist, existence is what one experiences, including physical objects, other people, events, and processes. It is not enough to say that other minds might happen not to exist; the view is that the solipsist cannot attach meaning to thoughts, experiences, or emotions other than their own. The entry says no great philosopher has explicitly espoused the position.