For an introduction to the major theories of ethics, the reader should consult James Rachels, The Elements of Moral Philosophy, 4th ed. (2003).
Robert L. Arrington, Western Ethics: An Historical Introduction (1998), contains chapters on the major ethical thinkers from Plato onward. Timothy Shanahan and Robin Wang (eds.), Reason and Insight: Western and Eastern Perspectives on the Pursuit of Moral Wisdom (1996), offers introductory accounts of the major ethical traditions of both East and West, supplemented by extracts from the key texts.
A good introduction to the ethical thought of the period is William J. Prior, Virtue and Knowledge: An Introduction to Ancient Greek Ethics (1991).
Henry Chadwick, Augustine: A Very Short Introduction (1986, reissued 2001), is a useful study. John Finnis, Aquinas: Moral, Political and Legal Theory (1998), treats the most influential Scholastic writer on ethics.
Selections of the major texts of this period are brought together in D.D. Raphael (ed.), British Moralists, 1650–1800, 2 vol. (1969, reissued 1991). C.D. Broad, Five Types of Ethical Theory (1930, reissued 2000), includes clear accounts of the ethics of Butler, Hume, and Sidgwick.
Accessible introductory studies on Rousseau, Nietzsche, Hegel, and Marx have been published by Oxford University Press in its Very Short Introduction series. On Kant, readers should consult Roger J. Sullivan, An Introduction to Kant’s Ethics (1994).
The key articles on moral realism, expressivism, projectivism, and other positions in the contemporary debate can be found in Stephen Darwall, Allan Gibbard, and Peter Railton, Moral Discourse and Practice: Some Philosophical Approaches (1997).
The best short statement of an act-utilitarian position is J.J.C. Smart’s contribution to J.J.C. Smart and Bernard Williams, Utilitarianism: For and Against (1973, reprinted 1987). H.J. McCloskey, Meta-Ethics and Normative Ethics (1969), is a restatement of the ethic of prima facie duties with some modifications. Roslind Hursthouse, On Virtue Ethics (1999), is an informative study.
Ruth Chadwick (ed.), Encyclopedia of Applied Ethics, 4 vol. (1998), is a major reference source. Good anthologies of articles in applied ethics are Lawrence Hinman (ed.), Contemporary Moral Issues, 2nd ed. (2000); John Arthur (ed.), Morality and Moral Controversies, 6th ed. (2002); and Hugh Lafollette (ed.), Ethics in Practice, 2nd ed. (2002).