The Certainties of Delusion

Abstract

Bryan is delusional. His belief that he is able to “set the sun” and indeed doing so is a nice example of what is known as a bizarre delusion. It is so far out of the ordinary that it is apparent that something must be wrong with Bryan. Bizarre delusions are the most striking subset of an entire class of mental states, delusions, which play an important role as a diagnostic tool in psychiatry. Delusions are one of the marks of mental illness. But compare Bryan’s case with the following passage from Wittgenstein’s On Certainty: