In 1966 the English philosopher and novelist Colin Wilson published “Introduction To the New Existentialism” which included the following passage:¹⁰

For the ‘new existentialism’ is a revolution in psychology. It is the recognition that the usual distinction between sanity and insanity is a false one. We are all insane; the difference between Napoleon and a madman who believes he is Napoleon is a difference in degree, not in kind; both are acting on a limited set of assumptions.