Expanding on the theory of ethics first posited by Brentano in The Origin of our Knowledge of Right and Wrong this re-issued work, first published posthumously in 1952, is based on series of lectures on practical philosophy, given at the university of Vienna from 1876 to 1894. The English-speaking reader will find it interesting to examine the step-by-step development of Brentano’s ethical theory, his extensive critique of British moral philosophers, and his unusually detailed section on casuistry.