This document provides an overview of the ethical theory of utilitarianism. It discusses the key aspects of utilitarianism, including that it is a teleological or consequentialist system that calls for maximizing the greatest amount of goodness and happiness for the greatest number of people. It outlines the views of early utilitarian philosophers Jeremy Bentham and John Stuart Mill, and discusses different versions of utilitarianism like act- and rule-utilitarianism. The document also examines some of the main criticisms of utilitarianism, such as issues with measuring and calculating utility, the possibility of justifying normally impermissible actions, and concerns that it could violate integrity or justice.