EmotivismEmotivism is a meta-ethical view that claims that ethical sentences do not express propositions but emotional attitudes. Hence, it is colloquially known as the hurrah/boo theory. Influenced by the growth of analytic philosophy and logical positivism in the 20th century, the theory was stated vividly by A. J. Ayer in his 1936 book Language, Truth and Logic, but its development owes more to C. L. Stevenson. Emotivism can be considered a form of non-cognitivism or expressivism.
Universal prescriptivismUniversal prescriptivism (often simply called prescriptivism) is the meta-ethical view that claims that, rather than expressing propositions, ethical sentences function similarly to imperatives which are universalizable—whoever makes a moral judgment is committed to the same judgment in any situation where the same relevant facts pertain. This makes prescriptivism a universalist form of non-cognitivism. Prescriptivism stands in opposition to other forms of non-cognitivism (such as emotivism and quasi-realism), as well as to all forms of cognitivism (including both moral realism and ethical subjectivism).
ExpressivismIn meta-ethics, expressivism is a theory about the meaning of moral language. According to expressivism, sentences that employ moral terms – for example, "It is wrong to torture an innocent human being" – are not descriptive or fact-stating; moral terms such as "wrong", "good", or "just" do not refer to real, in-the-world properties. The primary function of moral sentences, according to expressivism, is not to assert any matter of fact but rather to express an evaluative attitude toward an object of evaluation.
Moral universalismMoral universalism (also called moral objectivism) is the meta-ethical position that some system of ethics, or a universal ethic, applies universally, that is, for "all similarly situated individuals", regardless of culture, race, sex, religion, nationality, sexual orientation, gender identity, or any other distinguishing feature. Moral universalism is opposed to moral nihilism and moral relativism.
Ideal observer theoryIdeal observer theory is the meta-ethical view which claims that ethical sentences express truth-apt propositions about the attitudes of a hypothetical ideal observer. In other words, ideal observer theory states that ethical judgments should be interpreted as statements about the reactions that a neutral and fully informed observer would have; "x is good" means "an ideal observer would approve of x".
Quasi-realismQuasi-realism is the meta-ethical view which claims that: Ethical sentences do not express propositions. Instead, ethical sentences project emotional attitudes as though they were real properties. This makes quasi-realism a form of non-cognitivism or expressivism. Quasi-realism stands in opposition to other forms of non-cognitivism (such as emotivism and universal prescriptivism), as well as to all forms of cognitivism (including both moral realism and ethical subjectivism).
Non-cognitivismNon-cognitivism is the meta-ethical view that ethical sentences do not express propositions (i.e., statements) and thus cannot be true or false (they are not truth-apt). A noncognitivist denies the cognitivist claim that "moral judgments are capable of being objectively true, because they describe some feature of the world". If moral statements cannot be true, and if one cannot know something that is not true, noncognitivism implies that moral knowledge is impossible.
Moral realismMoral realism (also ethical realism) is the position that ethical sentences express propositions that refer to objective features of the world (that is, features independent of subjective opinion), some of which may be true to the extent that they report those features accurately.
Divine command theoryDivine command theory (also known as theological voluntarism) is a meta-ethical theory which proposes that an action's status as morally good is equivalent to whether it is commanded by God. The theory asserts that what is moral is determined by God's commands and that for a person to be moral he is to follow God's commands. Followers of both monotheistic and polytheistic religions in ancient and modern times have often accepted the importance of God's commands in establishing morality.
Ethical intuitionismEthical intuitionism (also called moral intuitionism) is a view or family of views in moral epistemology (and, on some definitions, metaphysics). It is foundationalism applied to moral knowledge, the thesis that some moral truths can be known non-inferentially (i.e., known without one needing to infer them from other truths one believes). Such an epistemological view is by definition committed to the existence of knowledge of moral truths; therefore, ethical intuitionism implies cognitivism.
