On 14-11-2013 I gave a short talk for the Practical Philosophy section on Brentano’s best-known work on ethics Vom Ursprung sittlicher Erkenninis (1889) translated as The Origin of our Knowledge of Right and Wrong (1902). The book was famously reviewed by G.E. Moore (International Journal of Ethics, Vol. 14, No. 1 (Oct., 1903), pp. 115-123) as the best work in ethics, ever:

“This is a far better discussion of the most fundamental principles of Ethics than any others with which I am acquainted. Brentano himself is fully conscious that he has made a very great advance in the theory of Ethics. … In almost all points in which he differs from any of the great historical systems, he is in the right; and he differs with regard to the most fundamental points of Moral Philosophy. … It would be difficult to exaggerate the importance of his work.”

In the work Brentano is looking for a “natural moral law which, in its nature, is universal and valid for every place and time, valid indeed for every kind of thinking and sentient being”. As a practical maxim, he proposes to “do the best that is attainable”. But what is best, better, or good? “We call something good when the love relating to it is right.” and the better is what “when compared with another good, is preferable, i.e. something which for its own sake, is preferred with a right preference”. Brentano’s conclusion then is that:

“The province of the highest practical good embraces everything which is subject to our rational operation in so far as a good can be realized in such matter. Not merely the self but also the family, the town, the state, the whole present world of life, even distant future times, may here be taken into account. All this follows from the principle of the summation of the good. To promote as far as possible the good throughout this great whole, that is manifestly the right end in life, towards which every act is to be ordered; that is the one, the highest command upon which all the rest depend.”

The natural sanction of morality is then found “written within the hearts of the people”, i.e. public opinion, which has “good and bad reputation” as reward and punishment. Such a “positive code of morality” complements the positive code of law, harmonizing with our “duty of love towards the highest practical good”.