Some preliminary definitions of meta-ethical terms

amoralism - 1. a mode of thought or behavior that disregards all moral concepts, principles, or values. 2. a denial of the existence of morality. 3. an indifference to, or disregard of, moral principles or norms

meta-ethics - 1. the study of the origin, nature, and meaning of moral judgments, attitudes, properties, and values. 2. the study of the methods, language, and modes of reasoning that are employed in ethics

moral absolutism - the theory that there are absolute moral truths that are not relative to the individual moral agent or the sociocultural context in which moral judgments are made

moral anti-realism (or irrealism) - the theory that moral properties or values do not exist independently of our perceptions of them

moral cognitivism - 1. the theory that there are moral facts, and that moral statements express propositions (which can be shown to be true or false). 2. the theory that moral judgments are cognitive evaluations of facts, and that they have the same cognitive status as beliefs. 3. the theory that moral judgments are beliefs that have propositional content.
      Terry Horgan and Mark Timmons (2000) explain that moral cognitivism may be descriptivist or non-descriptivist, insofar as there may or may not be moral evaluative beliefs that are reducible to, or a species of, moral descriptive beliefs.¹

      Alfred Mele (1996) explains that moral cognitivism may also be internalist or externalist with regard to its analysis of moral motivation (depending on whether it regards an individual's own moral judgments as necessarily or only contingently motivating him/her to perform a particular action).² 

moral coherentism - the theory that moral judgments are justified insofar as they cohere with other moral judgments that are held to justified

moral constructivism - the theory that moral truths are (psychologically, rationally, or socially) constructed

moral contextualism - the theory that moral truths are context-sensitive, and that the validity of moral judgments depends on the context in which they are made

moral descriptivism - the theory that moral judgments describe facts

moral discourse - language that occurs within a specific (situational, sociocultural, or historical) context, and that concerns moral perceptions, feelings, emotions, concepts, attitudes, judgments, or values

moral emotivism - the theory that moral judgments do not express propositions, and that they instead express emotions or feelings

moral epistemic foundationalism - the theory that there are justified moral beliefs or judgments that are basic and foundational elements of moral knowledge, insofar as they do not have to be inferred from, or justified by, other justified moral beliefs or judgments. Epistemic foundationalism is therefore a solution to the problem of infinite regress in epistemic justification (the problem of an infinite number of inferences being required to justify any belief or judgment, unless there are some beliefs or judgments that are self-evidently justified and that do not require inferential justification).

moral epistemic reliabilism - the theory that a moral judgment is epistemically justified if the method by which the judgment was made is epistemically reliable.

moral epistemology - the study of the origin, nature, and limits of moral knowledge. Various approaches to moral epistemology (including intuitionism, coherentism, constructivism, and reliabilism) may be taken in order to explain how moral knowledge is possible.

moral error theory - 1. the theory that all moral beliefs are false, because they ascribe moral properties to things that have no moral properties.³ 2. the theory that all moral beliefs are false, because there are no moral facts or properties that could enable them to be true.⁴ Moral error theory may be compatible with moral subjectivism and moral fictionalism. It may also be compatible with moral anti-realism, but it may not be compatible with the epistemological claim made by moral non-cognitivism that moral statements cannot be shown to be true or false.

moral expressivism - the theory that moral judgments do not express propositions, and that they are instead expressions of feelings or emotions

moral externalism (or motivational externalism) - the theory that the moral motivation for an individual's actions is (or may be) provided by factors other than his/her own moral reasoning, attitudes, and judgments.

moral fictionalism - the theory that moral properties are not literally present in things, and that they are merely fictions created for the sake of convenience or expediency

moral functionalism - as described by Frank Jackson and Philip Pettit (1995), a theory of moral content according to which the evaluative content of moral judgments supervenes upon their descriptive content and thus functions to provide the motivation for moral action.⁵

moral generalism - the theory that there are general moral principles that can be used to guide moral conduct in particular situations

moral identity - the aspect of a person's social identity that is defined by his/her moral perceptions, feelings, reasoning, emotions, attitudes, and behavior 

moral imagination - the ability to imagine alternative moral actions, principles, and values, and to consequently engage with, and have a fuller conception of, the moral capacities of the individual, group, or society

moral internalism (or motivational internalism) - the theory that the moral motivation for an individual's actions is provided by his/her own moral reasoning, attitudes, and judgments. The theory may have strong and weak forms, depending on whether an individual's own moral reasoning, attitudes, and judgments are seen as determining or merely contributing to his/her actions. 

moral intuitionism - the theory that some justified moral judgments can be made intuitively, without having to be justified by other judgments. Moral intuitionism may be a kind of foundationalism, insofar as intuitively-made justified judgments may be considered to be foundational for other judgments.⁶

moral language - 1. the language of morality. 2. language that employs moral concepts, terms, and arguments. 3. language that has moral meaning, aims, and content. 4. language that presupposes (or advocates for) a particular set of moral values or norms

moral naturalism  - the theory that there are moral facts or properties in the natural world (or that moral properties are determined by natural properties)⁷

moral nihilism - 1. rejection of any concept of morality. 2. rejection of any mode of moral judgment. 3. denial of the existence of any objective moral truths, values, properties, or facts

moral non-cognitivism - 1. the theory that there are no moral facts, and that moral statements therefore do not express propositions.⁸ 2. the theory that moral judgments do not have the same cognitive status as beliefs, because there are no moral facts about which moral judgments can be made. Moral non-cognitivism may be a kind of non-objectivism.

moral non-descriptivism -  the theory that moral judgments do not describe facts

moral non-naturalism - the theory that there are no moral facts or properties in the natural world 

moral non-objectivism - the theory that there are no objective moral truths or facts

moral normativity - 1. the ability or tendency of something to be morally normative. 2. the ability or tendency of something to establish a moral norm or standard of behavior

moral objectivism - the theory that there are objective moral truths, properties, or values

moral particularism - the theory that there are no general moral principles that can be used to guide moral conduct in particular situations

moral philosophy - 1. the branch of philosophy that studies the nature of morality, and that explores the nature of right and wrong. 2. the branch of philosophy that investigates the origin and nature of moral reasoning, principles, values, and conduct. 3. the branch of philosophy that examines the applications of moral norms to human behavior. 

moral prescriptivism - the theory that moral judgments have prescriptive rather than descriptive content

moral projectivism - the projection of moral properties, attitudes, or values onto persons or things

moral psychology - the study of mental states and processes as they relate to moral reasoning, judgment, and conduct. Moral psychology may include the study of moral identity, moral development, moral motivation, and the neuroscience of cognition as it relates to moral thinking, attitudes, and behavior.

moral quasi-realism - as described by Simon Blackburn (1993), the theory that moral judgments do not express propositions, and that they merely express or project feelings (or attitudes) as if the latter were about actual facts. Quasi-realism is compatible with non-cognitivism, expressivism, projectivism, and anti-realism.⁹

moral queerness - a property described by J.L. Mackie (1977), who argues that there are no objective moral facts or values, and that if there were, they would be facts or values of a very strange and queer sort, unlike anything else in the universe. They would require some special faculty of intuition or perception, unlike any other kind of human perception, in order to be recognized.¹⁰ Mackie calls this argument against moral objectivism "the argument from queerness."

moral rationalism - the theory that the truth or falsehood of moral judgments can be determined by reason alone

moral realism - the theory that there are moral facts, attributes, or values that exist independently of our perception of them

moral relativism - the theory that there are no moral truths, properties, or values that are not relative to the judgment of the individual moral agent or to the sociocultural setting in which moral judgments are made

moral skepticism -  an attitude of doubt regarding the existence of any objective moral truths or facts, and doubt regarding the validity of any moral judgments that presuppose such truths or facts

moral subjectivism - the theory that all moral judgments, properties, or values are subjective. Moral subjectivism may be a kind of anti-realism or skepticism.¹¹

moral supervenience - a relation whereby moral properties supervene on non-moral properties, so that a given set of moral properties is found wherever a given set of non-moral properties is found. Moral anti-realists argue that moral realists have not provided any convincing argument for why moral supervenience should hold.¹²

moral understanding - 1. the understanding of moral principles and reasoning. 2. the ability to combine moral reasoning with other kinds of reasoning

moral vision - a particular moral viewpoint, perspective, or way of looking at the world

¹Terry Horgan and Mark Timmons, "Nondescriptivist Cognitivism: Framework for a New Metaethic" in Philosophical Papers 29 (2000), 121-53.

²Alfred R. Mele, "Internalist Moral Cognitivism and Listlessness," in Ethics, Vol. 106, No. 4 (1996), pp. 727-753.

³Bart Streumer, "Can We Believe the Error Theory?" (2012), forthcoming in the Journal of Philosophy.

⁴Richard Joyce, "Error theory," International Encyclopedia of Ethics, ed. by Hugh LaFollette (Wiley-Blackwell), 2013.

⁵Frank Jackson and Philip Pettit, "Moral Functionalism and Moral Motivation" in The Philosophical Quarterly, Vol. 45, No. 178 (Jan., 1995), pp. 20-40.

⁶Mark van Roojen "Moral Intuitionism, Experiments and Skeptical Arguments" in Intuitions, edited by Anthony Booth and Darrell P. Rowbottom (Oxford: Oxford University Press, 2013).

⁷Nick Zangwill, "Against Analytic Moral Functionalism" in Ratio XIII 3 September 2000, p. 275.

⁸Mark van Roojen, "Moral Cognitivism vs. Non-Cognitivism," Stanford Encyclopedia of Philosophy (2009), online at http://plato.stanford.edu/entries/moral-cognitivism/.

⁹Simon Blackburn, Essays in Quasi-Realism (Oxford: Oxford University Press, 1993).

¹⁰J.L. Mackie, Ethics: Inventing Right and Wrong (Harmondsworth: Penguin Books, 1977), p. 38.

¹¹Ibid., p. 18.

¹²Nick Zangwill, "Moral Supervenience," in Midwest Studies in Philosophy, XX (1995), p. 240.