Originally published in 1861, Mill's great work systematically details and defends the doctrine of utilitarianism. Arguing first that a "morally good" action is one that increases the general sum of happiness in the world, Mill then says that general principles of justice should be based on this idea. The right thing to do is the thing that brings about the most happiness and the least unhappiness for all people. Therefore, in life, there is no conflict between what is just and what is morally right. Initially met with hostility, Utilitarianism is now regarded as a classic text in the history of political philosophy.