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 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.
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.
Cognitivism (ethics)Cognitivism is the meta-ethical view that ethical sentences express propositions and can therefore be true or false (they are truth-apt), which noncognitivists deny. Cognitivism is so broad a thesis that it encompasses (among other views) moral realism (which claims that ethical sentences express propositions about mind-independent facts of the world), ethical subjectivism (which claims that ethical sentences express propositions about peoples' attitudes or opinions), and error theory (which claims that ethical sentences express propositions, but that they are all false, whatever their nature).
Secular ethicsSecular ethics is a branch of moral philosophy in which ethics is based solely on human faculties such as logic, empathy, reason or moral intuition, and not derived from belief in supernatural revelation or guidance—a source of ethics in many religions. Secular ethics refers to any ethical system that does not draw on the supernatural, and includes humanism, secularism and freethinking. A classical example of literature on secular ethics is the Kural text, authored by the ancient Indian philosopher Valluvar.
Naturalistic fallacyIn philosophical ethics, the naturalistic fallacy is the claim that it is possible to give a reductive explanation of good, in terms of natural properties such as pleasant or desirable. The term was introduced by British philosopher G. E. Moore in his 1903 book Principia Ethica. Moore's naturalistic fallacy is closely related to the is–ought problem, which comes from David Hume's A Treatise of Human Nature (1738–40). However, unlike Hume's view of the is–ought problem, Moore (and other proponents of ethical non-naturalism) did not consider the naturalistic fallacy to be at odds with moral realism.
MetaethicsIn metaphilosophy and ethics, metaethics is the study of the nature, scope, and meaning of moral judgment. It is one of the three branches of ethics generally studied by philosophers, the others being normative ethics (questions of how one ought to be and act) and applied ethics (practical questions of right behavior in given, usually contentious, situations).
Categorical imperativeThe categorical imperative (kategorischer Imperativ) is the central philosophical concept in the deontological moral philosophy of Immanuel Kant. Introduced in Kant's 1785 Groundwork of the Metaphysics of Morals, it is a way of evaluating motivations for action. It is best known in its original formulation: "Act only according to that maxim whereby you can at the same time will that it should become a universal law.
Moral relativismMoral relativism or ethical relativism (often reformulated as relativist ethics or relativist morality) is used to describe several philosophical positions concerned with the differences in moral judgments across different peoples and cultures. An advocate of such ideas is often referred to as a relativist for short. Descriptive moral relativism holds only that people do, in fact, disagree fundamentally about what is moral, with no judgment being expressed on the desirability of this.
Ethical naturalismEthical naturalism (also called moral naturalism or naturalistic cognitivistic definism) is the meta-ethical view which claims that: Ethical sentences express propositions. Some such propositions are true. Those propositions are made true by objective features of the world. These moral features of the world are reducible to some set of non-moral features. The versions of ethical naturalism which have received the most sustained philosophical interest, for example, Cornell realism, differ from the position that "the way things are is always the way they ought to be", which few ethical naturalists hold.
