This chapter reviews what the great eighteenth and nineteenth-century utilitarians had to say about war. Henry Sidgwick, the last of classical utilitarians, wrote about war in his Elements of Politics and in some popular essays. In the former work, Sidgwick sought to outline the system of international rules, for which it is desirable to obtain and not unreasonable to hopegeneral acceptance. Sidgwick firmly rejects national egoism or the doctrine that states have no moral duties limiting the pursuit of their interests: For a State, for an individual, the ultimate end and standard of right conduct is the happiness of all who are affected by its actions. Like Paley contemporary the utilitarian radical William Godwin, Bentham disapproved of war more strongly than Paley appears to have done, and he sought its elimination. An anachronism in the modern world, war damages the interests of masses, forcing them to murder one another for the gratification of the avarice or pride of the few.