(1) Descriptive ethics, mere description of morality in different cultures;We can provide the general classification of normative ethical theories here:
(2) Normative ethics, the study of systems that dictate morally correct conduct;
(3) Metaethics, discussion of meanings of moral terms without directives.
I have made a more detailed list below of the major objective ethical theories and their classification.
- (1) Non-cognitivism
- (1) Emotivism (Spinoza, Hume, C. L. Stevenson, A. J. Ayer)
- (2) Prescriptivism (R. M. Hare)
- (3) cognitivist expressivism (S. Blackburn; M. Timmons 1999; T. Horgan)
- (2) Cognitivism
- (i) Anti-realism
- (a) Moral subjectivism
- (b) Error theory
- (ii) Moral realism
- (a) Ethical naturalism
- Non-theological natural rights theory
- neo-Aristotelian ethical naturalism (P. Foot; R. Hursthouse)
- (b) Ethical non-naturalism
- G. E. Moore ethical intuitionism/agathistic consequentialism
- Platonist ethics
- divine command ethics
- Kantian ethics
I will just make some quick remarks here.
- (1) Deontological ethics
- (a) Moral absolutism
- (i) Divine Command Theory
- (ii) Categorical Imperative ethics (Kantian ethics)
- (b) Moral Universalism (minimal/moderate moral realism)
- (i) Natural law theories (Plato and many Christian philosophers)
- (ii) Natural rights theories
- (iii) Thomist ethics
- (iv) Pluralistic deontology, the non-absolutist ethics of W.D. Ross
- (v) Human rights objectivism (Rawls)
- (2) Teleological/Consequentialist ethics:
- (a) Virtue Ethics
- (i) Eudaemonist theories
- (ii) Plato’s eudaemonist ethics
- (iii) Aristotle’s eudaemonist ethics
- (iv) Stoic ethics (with natural law)
- (v) non-eudaemonist virtue ethics
- (vi) agent-based virtue ethics of Michael Slote (2001)
- (vii) neo-Aristotelian ethical naturalism (P. Foot; R. Hursthouse)
- (b) Consequentialist (minimal/moderate moral realism)
- (i) Utilitarian-type theories
- - Hedonism
- - egoism (the 17th-century English philosopher Thomas Hobbes)
- - universal/universalistic hedonism = utilitarianism (Bentham, Mill, and Sidgwick): act utilitarianism, rule utilitarianism
- (ii) Other teleological/utilitarian-type
- - ideal-moral-code rule consequentialism (Hooker 2000; Richard Brandt)
- - preference rule consequentialism (John Harsanyi)
- - Motive consequentialism (Robert Adams)
- - ideal consequentialism/utilitarianism (G.E. Moore; Hastings Rashdall)
- - preference consequentialism/utilitarianism (R. M. Hare; Peter Singer)
- - two-level preference consequentialism/utilitarianism (R. M. Hare)
- - Negative consequentialism (Popper, Christoph Fehige and Clark Wolf)
- - evolutionary ethics, with ends of action, survival and growth (Herbert Spencer) power, as in despotism (Niccolò Machiavelli and Friedrich Nietzsche)
- - satisfaction and adjustment, pragmatism (Ralph Barton Perry and John Dewey)
- - freedom, existentialism (Jean-Paul Sartre)
- - Buddhist ethics
- - Mohism (Mo Tzu/Micius)
- - Ayn Rand’s objectivism?
- (3) Ayn Rand’s objectivism?
- (4) Utilitarian Kantian Principle of James Cornman (combines deontology and utilitarianism).
Non-cognitivism contends that moral statements do not express propositions and have no truth values.
These theories include G. E. Moore’s intuitionism/agathistic consequentialism; Platonist ethics; divine command ethics, and Kantian ethics. Moral knowledge is a non-natural property known by (1) intuition, (2) god’s command or (3) a priori reasoning in these theories.
Ethical naturalism holds that moral knowledge is empirical in the sense that we can use the methods of the natural and social sciences to understand it. Moral concepts are reducible to, or definable in, non-ethical, natural terms. Most utilitarian theories are in the class of moral naturalism:
“even utilitarians who object to hedonism in its original, Benthamite form, as Mill expressly did, and utilitarians who stray even farther from the hedonistic fold, as I will suggest that Mill, perhaps unwittingly, also did, usually agree that the good is one or another kind of natural property. The dominant view, in other words, is that whatever is intrinsically good is part of nature. It is therefore fair to say that, with very few exceptions, utilitarians are ethical naturalists. One can be a utilitarian, though, and not be an ethical naturalist. For example, G. E. Moore, one of the founders modern analytic philosophy, was a utilitarian. He was as committed as Bentham or Mill to enhancing overall goodness by maximizing social utility, taking social utility to be the logical sum of individuals’ utilities. However, Moore famously opposed ethical naturalism, insisting that the very idea rest on what he disparagingly called the ‘naturalistic fallacy’. In direct opposition to Mill, Moore maintained that the good can only be a non natural property...” (Levine 2002: 136).According to Moore, all naturalist ethical theories commit the naturalistic fallacy.
The deontological theories (or duty/obligation based morality) hold that the basis of morality is duty and some acts are always right no matter what consequences they can cause (the best example of which is Kantian ethics or some forms of divine command theory; Kant famously said that it is always wrong to lie, no matter what the circumstances).
The Eudaemonist theories of ethics are those that hold that morality consists in some activity appropriate to man as a human being, and thus tend to emphasize the cultivation of virtue or excellence as the end of our action or moral life. These theories were mainly held by the ancient Greeks and Romans.
The utilitarian theories hold that utility/happiness is the end we should aim at, and the rightness or wrongness of an action is judged by ability to create more utility/happiness in the world.
Consequentialist theories hold that other ends are also important, and not just utility.
Hooker, B. 2000. Ideal Code, Real World: A Rule-Consequentialist Theory of Morality, Oxford University Press, Oxford, England and New York.
Levine, A. 2002. Engaging Political Philosophy: From Hobbes to Rawls, Blackwell, Malden, Mass.