In Defense of Utilitarianism, C.L. Sheng provides a more intensive study of the Unified Utilitarian Theory (UUT), which he proposed in his previous work A New Approach to Utilitarianism (Kluwer Academic Publishers, 1991). Sheng defends utilitarianism, particularly UUT, against the objections and attacks raised by nonutilitarians, showing it to be a viable ethical theory. He argues that utilitarianism is not person-neutral, is not indifferent to distribution, and is not a theory of replacement, utilitarian sacrifice, or trade-offs. By refuting the conception of absolute principles and adopting nonstrict rules, Sheng shows how UUT can avoid all objections to act-utilitarianism and rule-utilitarianism, making it a viable theory.