This collection of the highly regarded Herbert Spencer Lectures (Oxford University) is intended to survey the profound influence on many disciplines of the Darwinian theory of evolution by natural selection. The noted contributors include A.J. Cain, the Hon. W.G. Runciman, R.J. Herrnstein, Maurice Godelier, Bernard Williams, and E.H. Gombrich. Their authoritative observations review the impact of Darwinism in art, philosophy, sociology, psychology, and other fields of human knowledge and endeavor.