First published in 1913, Jevons’ marries the disciplines of philosophy and psychology in order to question the existence of personality and the arguments surrounding it. Intriguingly, Jevons suggests that if a person can question their own personality and existence, by extension they can also question the personality and existence of God. The book is arranged into four chapters based on a series of lectures delivered in Oxford in 1912: these discuss such areas as the relationship between science, psychology, and personality; the argument that "there are changes, but no things which change", and consequently there are changes, but no persons who change; and, the concepts of individualism and unity.