First published in 1999. The author writing in 1923, starts with the assumption that conduct originates in the actor himself, and tries to discover what intelligent conduct may mean if we follow this assumption to its limits. He then sets about to harmonize three schools of thought about human nature which have the appearance of being irreconcilably disparate. Stated in a nutshell, his message is that "psychology starts with the unrest of the inner self, and it completes its discovery in the contentment of the inner self".