Aldous Huxley: The Art of Self-Knowledge

By: Aldous Huxley (The Perennial Philosophy)

In other living creatures ignorance of self is nature; in man it is vice.

—Boethius

Vice may be defined as a course of behaviour consented to by the will and having results which are bad, primarily because they are God-eclipsing and, secondarily, because they are physically or psychologically harmful to the agent or his fellows.

Ignorance of self is something that answers to this description.