Utilitarianism is a philosophical defense of utilitarianism in ethics. Although Mill includes discussions of utilitarian ethical principles in other works, such as On Liberty and The Subjection of Women, Utilitarianism contains Mill’s only major discussion of the fundamental grounds for utilitarian ethical theory.
Mill defines utilitarianism in terms of the general moral principles that it uses to judge concrete actions. Utilitarianism also discusses questions concerning the motivation to follow utilitarian moral principles. Finally, to be truly happy, Mill believes that we must turn our attention away from our own happiness towards other objects and ends, such as doing good for others and such high pleasures in life as art and music.