Cultural relativism - “Good” means “socially approved.” Pick out your moral principles by following what your society approves of.
Subjectivism - “X is good” means “I like X.” Pick out your moral principles by following your feelings.
Ideal observer - “X is good” means “We’d desire X if we were fully informed and had impartial concern for everyone.” Pick out your moral principles by trying to become as informed and impartial as possible— and then seeing what you desire.
Supernaturalism - “X is good” means “God desires X.” Pick out your moral principles by following God’s will.
Intuitionism - “Good” is indefinable. There are objective moral truths. Pick out your moral principles by following your basic moral intuitions.
Emotivism - “X is good” is an emotional exclamation (not a truth claim), and means “Hurrah for X!” Pick out your moral principles by following your feelings.
Prescriptivism - “You ought to do this” is a universalizable prescription (not a truth claim); it means “Do this and let everyone do the same in similar cases.” Pick out your moral principles first trying to be informed and imaginative, and then seeing what you can consistently hold.
Classical utilitarianism - We ought to do whatever maximizes the balance of pleasure over pain for everyone affected by our action.
Pluralistic rule utilitarianism - We should evaluate consequences in terms of various goods, including virtue, knowledge, pleasure, life, and freedom. We ought to do what would be prescribed by the rules with the best consequences for people in society to try to follow.
Nonconsequentialism - Ross’s Prima Facie View - The basic moral principles say that we ought, other things being equal, to do or not to do certain kinds of things: keep our promises, do good to others, not harm others, and so forth.
See how these apply by contrast to three different issues: consistency (pp. 98-99, golden rule (pp. 118-119), and abortion (pp. 181-182).
Other points to consider include two basic logical rules for “ought” (p. 75), avoid inconsistencies (p. 85), golden rule theorem (p. 104), formula of universal law (p. 116), four derivative principles (p. 117), moral rationality (p. 123), five commandments (pp. 132-133), morality components (p. 134), our basic duties (p. 160), virtues and rights (p. 170), and normative ethics (p. 170).
Also see glossary (pp. 201-205).