Virtue theory is a branch of moral philosophy that emphasizes character, rather than rules or consequences, as the key element of ethical thinking. In the West virtue ethics was the prevailing approach to ethical thinking in the ancient and medieval periods. The tradition suffered an eclipse during the early modern period, as Aristotelianism fell out of favour in the West. Virtue theory returned to prominence in Western philosophical thought in the twentieth century, and is today one of the three dominant approaches to normative theories (the other two being deontology and consequentialism).
Although concern for virtue appears in several philosophical traditions, notably the Chinese, in the West the roots of the tradition lie in the work of Plato and Aristotle, and even today the tradition’s key concepts derive from ancient Greek philosophy. These concepts include arete (excellence or virtue), phronesis (practical or moral wisdom), and eudaimonia (flourishing).
This disagreement over the meaning of virtue points to a larger conflict between virtue theory and its philosophical rivals. A system of virtue theory is only intelligible if it is teleological: that is, if it includes an account of the purpose (telos) of human life, or in popular language, the meaning of life. Obviously, strong claims about the purpose of human life, or of what the good life for human beings is, will be highly controversial. Virtue theory's necessary commitment to a teleological account of human life thus puts the tradition in sharp tension with other dominant approaches to normative ethics, which, because they focus on actions, do not bear this burden.
Although eudaimonia was first popularized by Aristotle, it now belongs to the tradition of virtue theories generally. For the virtue theorist, eudaimonia describes that state achieved by the person who lives the proper human life, an outcome which can be reached by practicing the virtues. A virtue is a habit or quality that allows the bearer to succeed at his, her, or its purpose. The virtue of a knife, for example, is sharpness; among the virtues of a racehorse is speed. Thus to identify the virtues for human beings, one must have an account of what the human purpose is. There is, and always has been, sharp disagreement on this question: thus, as Alasdair MacIntyre observed in After Virtue, though thinkers as diverse as Homer, Aristotle, the authors of the New Testament, Thomas Aquinas, and Benjamin Franklin have all proposed lists of the virtues, these lists often fail to overlap.
Aristotle categorized the virtues as moral and intellectual. Aristotle identified nine intellectual virtues, the most important of which were sophia (theoretical wisdom) and phronesis (practical wisdom). The moral virtues included prudence, justice, fortitude, and temperance. Aristotle argued that each of the moral virtues was a mean (see Golden Mean) between two corresponding vices. For example, the virtue of courage is a mean between the two vices of cowardice and foolhardiness. Where cowardice is the disposition to act more fearfully than the situation deserves, and foolhardiness is the disposition to show too little fear for the situation, courage is the mean between the two: the disposition to show the amount of fear appropriate to the situation.
The tradition was eclipsed in the Renaissance, and throughout the early modern period, when the Aristotelian synthesis of ethics and metaphysics fell into disfavour. Though the tradition receded into the background of European philosophical thought in these centuries, the term "virtue" remained current during this period, and in fact appears prominently in the tradition of classical republicanism or classical liberalism. This tradition was prominent in the intellectual life of sixteenth-century Italy, as well as seventeenth- and eighteenth-century Britain and America; indeed the term "virtue" appears frequently in the work of Machiavelli, Hume, the republicans of the English Civil War period, the eighteenth-century English Whigs, and the prominent figures among the Scottish Enlightenment and the American Founding. Despite this common term, classical republicanism should not be conflated with virtue theory, as the two philosophical traditions draw from different sources and often address different concerns. Where virtue theory traces its roots to Aristotle, classical republicanism draws primarily on Tacitus. Virtue theory emphases Aristotle's belief in the polis as the acme of political organization, and the role of the virtues in enabling human beings to flourish in that environment. Classical republicanism in contrast emphasizes Tacticus' concern that power and luxury can corrupt individuals and destroy liberty, as Tacitus perceived in the transformation of the Roman republic into an empire; virtue for classical republicans is a shield against this sort of corruption and preserve the good life one has, rather than a means by which to achieve the good life one does not yet have. Another way to put the distinction between the two traditions is that virtue ethics relies on Aristotle's fundamental distinction between the human-being-as-he-is from the human-being-as-he-should-be, while classical republicanism relies on the Tacitean distinction of the human-being-as-he-is from the human-being-as-he-is-at-risk-of-becoming.
Other proponents of virtue theory, notably Alasdair MacIntyre, respond to this objection by arguing that any account of the virtues must indeed be generated out of the community in which those virtues are to be practiced: the very word 'ethics' implies 'ethos'. That is to say that the virtues are, and necessarily must be, grounded in a particular time and place. What counts as virtue in fourth-century Athens would be a ludicrous guide to proper behaviour in twenty-first-century Toronto, and vice-versa. To take this view does not necessarily commit one to the argument that accounts of the virtues must therefore be static: moral activity-- that is, attempts to contemplate and practice the virtues-- can provide the cultural resources that allow people to change, albeit slowly, the ethos of their own societies. MacIntyre appears to take this position in his seminal work on virtue ethics, After Virtue. One might cite (though MacIntyre does not) the rapid emergence of abolitionist thought in the slave-holding societies of the eighteenth-century Atlantic world as an example of this sort of change: over a relatively short period of time, perhaps 1760 to 1800, in Britain, France, and British America, slave-holding, previously thought to be morally neutral or even virtuous, rapidly became seen as vicious among wide swathes of society. While the emergence of abolitionist thought derived from many sources, the work of David Brion Davis, among others, has established that one source was the rapid, internal evolution of moral theory among certain sectors of these societies, notably the Quakers.
Another objection to virtue theory is that the school does not focus on what sorts of actions are morally permitted and which ones are not, but rather on what sort of qualities someone ought to foster in order to become a good person. In other words, while some virtue theorists may not condemn, for example, murder as an inherently immoral or impermissible sort of action, they may argue that someone who commits a murder is severely lacking in several important virtues, such as compassion and fairness. Still, antagonists of the theory often object that this particular feature of the theory makes virtue ethics useless as a universal norm of acceptable conduct suitable as a base for legislation. Some virtue theorists concede this point, but respond by opposing the very notion of legitimate legislative authority instead, effectively advocating some form of anarchism as the political ideal. Others argue that laws should be made by virtuous legislators. Still others argue that it is possible to base a judicial system on the moral notion of virtues rather than rules.
Some virtue theorists might respond to this overall objection with the notion of a "bad act" also being an act characteristic of vice. That is to say that those acts which do not aim at virtue, or stray from virtue, would constitute our conception of "bad behavior". Although not all virtue ethicists agree to this notion, this is one way the virtue ethicist can re-introduce the concept of the "morally impermissible". One could raise objection with Foot that she is committing an argument from ignorance by postulating that what is not virtuous is unvirtuous. In other words, just because an action or person 'lacks of evidence' for virtue does not, all else constant, imply that said action or person is unvirtuous.