Ethics: the critical study of the grounds and directive principles of good and bad, right and wrong.

One of the three recognized basic areas of philosophy that which is concerned with what is good and bad in human action, including competing positions of utilitarianism, deontological/formalist/duty ethics, emotivism/non-cognitivism, evolutionary ethics, intuitionism, naturalism, perfectionism, phenomenological ethics, postmodern ethics, subjectivism/pluralism/relativism, self-realization/teleological ethics, and virtue ethics. Perhaps the most enduring received meta-ethical debate is between consequentialism (judging by consequences, e.g., utilitarianism) and non-consequentialism (judging by the intrinsic principle of judgment and action e.g., Platonism and Kantianism). Moral philosophy is often equated to Ethics, but is in principle more restricted in reference to ought-to statements which entail prescriptions or prohibitions whose violation is thought to deserve guilt or punishment.

Broadly construed, ethics is the study of the good life, including both problems of universal (transhistorical and cross-cultural) value as well as the particular structures of value that rule in any given social epoch, as well as the natural, social, and cultural systems that underlie and condition ruling value-regimes.

Source: What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11.