What the book discusses is not Buddhism as the Chinese usually understand it, the six realms of reincarnation, and the karma of good fortune, but a Westernized version of Buddhism, which is roughly equivalent to removing all the "supernatural" factors in Asian Buddhism and treating the Buddha as a person. The enlightened philosopher left only the methodology of philosophy and meditation practice.

In a general sense, it is a simplified version of Buddhist "mindfulness meditation", from discovering the real self to gain insight into the real world!