2014 Reprint of Original 1918 Edition. Exact facsimile of the original edition, not reproduced with Optical Recognition Software. According to Kidd, emotion rather than reason is held to be the source of power in life, not knowledge of intellect. The author's distrust of reason as a source of power, no doubt a casualty of World War I, and his doubts regarding the efficacy of knowledge are expressed throughout this work. The intellectual factor is held to be of slight, incidental value in the civilizing process. Kidd's interpretation of the failure of Western civilization is done convincingly and his constructive suggestions for the basis of a new social order are also interesting and thought provoking. The work contains elements of stimulus and challenge throughout.