Moral realism is the meta-ethical view which claims that:

1. Ethical sentences express propositions.
2. Some such propositions are true.
3. Those propositions are made true by objective features of the world, independent of human opinion.

This makes moral realism a non-nihilist form of cognitivism. Moral realism stands in opposition to all forms of moral anti-realism, including ethical subjectivism (which denies that moral propositions refer to objective facts), error theory (which denies that any moral propositions are true), and non-cognitivism (which denies that moral sentences express propositions at all). Within moral realism, the two main subdivisions are ethical naturalism and ethical non-naturalism.

According to Richard Boyd^[1], moral realism means that:

1. Moral statements are the sorts of statements which are (or which express propositions which are) true or false (or approximately true, largely false, etc.);
2. The truth or falsity (approximate truth...) of moral statements is largely independent of our moral opinions, theories, etc.;
3. Ordinary canons of moral reasoning—together with ordinary canons of scientific and everyday factual reasoning—constitute, under many circumstances at least, a reliable method for obtaining and improving (approximate) moral knowledge.

Some examples of robust moral realists would be David Brink, John McDowell, Peter Railton^[2], Geoffrey Sayre-McCord^[3], Michael Smith, Russ Shafer-Landau^[4], G.E. Moore^[5], Ayn Rand, John Finnis, Richard Boyd, Nicholas Sturgeon^[6], and Thomas Nagel. Plato and (arguably) Immanuel Kant^[7] could also be considered moral realists. Norman Geras has argued that Karl Marx was a moral realist.^[8]

Robust versus minimal moral realism

The robust model of moral realism commits moral realists to three theses:^[9]

1. The semantic thesis: The primary semantic role of moral predicates (such as "right" and "wrong") is to refer to moral properties (such as rightness and wrongness), so that moral statements (such as "honesty is good" and "slavery is unjust") purport to represent moral facts, and express propositions that are true or false (or approximately true, largely false, and so on).
2. The alethic thesis: Some moral propositions are in fact true.
3. The metaphysical thesis: Moral propositions are true when actions and other objects of moral assessment have the relevant moral properties (so that the relevant moral facts obtain), where these facts and properties are robust: their metaphysical status, whatever it is, is not relevantly different from that of (certain types of) ordinary non-moral facts and properties.

The minimal model, on the other hand, leaves off the metaphysical thesis, treating it as matter of contention among moral realists (as opposed to between moral realists and moral anti-realists). This dispute is not insignificant, as acceptance or rejection of the metaphysical thesis is taken by those employing the robust model as the key difference between moral realism and moral anti-realism. Indeed, the question of how to classify certain logically possible (if eccentric) views—such as the rejection of the semantic and alethic theses in conjunction with the acceptance of the metaphysical thesis—turns on which model we accept ^[10]. Someone employing the robust model might call such a view "realist non-cognitivism," while someone employing the minimal model might simply place such a view alongside other, more traditional, forms of non-cognitvism.

The robust model and the minimal model also disagree over how to classify moral subjectivism (roughly, the view that moral facts are not mind-independent in the relevant sense, but that moral statements may still be true). The historical association of subjectivism with moral anti-realism in large part explains why the robust model of moral realism has been dominant—even if only implicitly—both in the traditional and contemporary philosophical literature on metaethics.^[10]

In the minimal sense of realism, R.M. Hare could be considered a realist in his later works, as he is committed to the objectivity of value judgments, even though he denies that moral statements express propositions with truth-values per se. Moral constructivists like John Rawls and Christine Korsgaard^[11] may also be realists in this minimalist sense; the latter describes her own position as procedural realism.

Advantages

The advantages of such a theory of ethics are numerous: in particular, moral realism allows the ordinary rules of logic (modus ponens, etc.) to be applied straightforwardly to moral statements. We can say that a moral belief is false or unjustified or contradictory in the same way we would about a factual belief. This is a problem for expressivism, as shown by the Frege-Geach problem.

Another advantage of moral realism is its capacity to resolve moral disagreements: If two moral beliefs contradict one another, realism says that they cannot both be right, and therefore everyone involved ought to be seeking out the right answer to resolve the disagreement. Contrary theories of meta-ethics have trouble even formulating the statement "this moral belief is wrong," and so they cannot resolve disagreements in this way.

Criticisms

Several criticisms have been raised against moral realism: The first is that, while realism can explain how to resolve moral conflicts, it cannot explain how these conflicts arose in the first place. A common response to this argument is that moral conflicts occur when an individual or group simply is not sufficiently educated in the fundamentals of realistic morality, and so are compelled to act in ways that transgress concrete moral boundaries.

Others are critical of moral realism because it postulates the existence of a kind of "moral fact" which is nonmaterial and does not appear to be accessible to the scientific method. Moral truths cannot be observed in the same way as material facts (which are objective), so it seems odd to count them in the same category. One emotivist counterargument (although emotivism is usually non-cognitivist) alleges that "wrong" actions produce measurable results in the form of negative emotional reactions, either within the individual transgressor, within the person or people most directly affected by the act, or within a (preferably wide) consensus of direct or indirect observers. Others disgregard this objection on the basis that it is only valid if the moral realist concedes to a naturalistic worldview.

References

Further reading

• Hume, David (1739). Treatise Concerning Human Nature, edited by L.A. Selby-Bigge. Oxford: Oxford University Press, 1888.
• Kim, Shin (2006). "Moral Realism", The Internet Encyclopedia of Philosophy, Fieser & Dowden (eds.). (link)

See also

• Ethics
• Moral absolutism
• Moral relativism
• Zeitgeist
• Expressivism
• Cognitivism
• Morality
• Moral skepticism
• Nominalism