Ancient philosophical ethics tends to be agent-centered, and concerned with questions about what kind of person we ought to strive to be, theories of virtue and “the good life.” Modern philosophical ethics tends to be act-centered, and concerned with questions about the norms of moral action and theories of value, what makes experience good or bad (or evil). Both the ancients and the moderns are concerned with questions of normative ethics, what we ought to do or be, and with questions of meta-ethics, how we may justify or motivate ethics.
Ancient normative ethics included “deontological” approaches that focused on duties and the rightness or wrongness of actions, based on conventional or universal religious law (nomos), as well as “teleological” approaches oriented to the consequences of actions and their long-run benefit or harm to the society or the individual. But the chief focus of ancient ethics was teleological, having to do with what kind of life one should live to attain fulfillment or happiness (eudaimonia), and on this issue there were sharply different opinions, particularly relating to the roles of the cooperative or self-restraining virtues within the good life.
Most sophists approved of a conventional set of goods--wealth, health, political power--attained by practical wisdom or prudence within the boundaries of legal justice. Other sophists argued that since these things were good by nature, and since moral laws were the creations of society, the truly wise and prudent man would secretly ignore morality and pursue a "princely" or "tyrannical life" of action, power and pleasure (bios tyrannos). The Pythagoreans, by contrast, preached the eternal good of a "spiritual way of life" (hodos tou biou) devoted to virtue, science and the Pythagorean community. The Atomists approved of hedonism, the doctrine that the good by nature consists in pleasure or enjoyment, but argued that maximum pleasure was to found in a private life of study and friendship, as opposed to the conventional ancient ideal of the politically engaged life, oriented to the polis and its well-being. Aristotle distinguishes the “life of action” (bios praktikos) and the “life of contemplation” (bios theoretikos) and prefers the latter, though he regards each as laudable in contrast to the deficient lives of pleasure-seeking and money-making. Socrates extolled the "care of the soul" and the “examined life” of reason and virtue; but made no claim to knowledge of a "divine good." His argument was that human happiness was found in rationality, expressed in the philosophical life.
Clearly, the ancient ethicists disagreed concerning (i) the “real meaning” of terms they might agree were human virtues, e.g. courage, prudence or wisdom, (ii) which qualities were genuine virtues, e.g. piety, temperance, justice, and (iii) the rank and relationships among the virtues, e.g. justice vs. wisdom, or whether they were independent of one another (the Unity of Virtue problem).
Ancient meta-ethics involved epistemological, metaphysical and psychological issues: whether there was such a thing as ethical knowledge and how ethical claims could be justified; whether morality and ethical ideals exist independently of human invention or are human constructs; and what the motivation is for ethical conduct. The Socratic tradition including Plato and Aristotle argues for ethical cognitivism against the Sophists and Atomists, each of whom takes a skeptical view of claims to ethical knowledge, though there is a tension between Socrates’ professed ability to disprove opposing/justify his own normative ethics (Socratic rationalism), and his stance of epistemological openness (Socratic ignorance). Plato and Aristotle also defend versions of ethical realism: in Plato, ethics is grounded metaphysically in the Forms (which can be known by dialectic and intuitive reason), whereas in Aristotle it is grounded metaphysically in the inner goal-directedness of human nature, which he argues cannot be fulfilled except in a life of virtue and reason. The Sophists, who are relativists and metaphysical anti-realists, and the Atomists, who are scientific realists, both reject the idea that human ethics are anything but ideas or constructs of human societies or individuals.
Finally, the ancient ethicists also differed concerning ethical motivation and its relation to "human nature." Most Sophists assume human beings are basically egoistic, but also naturally social, though some argued (a) social conditioning and "art" are more important than nature in determining what kind of people we are, whereas others argued (b) all humans are deeply egoistic, but whereas most submit to the internalized “conscience” society instills in them, a few are able to overthrow it and seek the (truly) good life of pleasure and power. Plato and Aristotle develop complex theories of ethical motivation which argue that the natural human interest in society and rationality promote non-egoistic ends. Plato's “Theory of the Tripartite Soul” divides human beings into three different ethical natures, according to the relative weight each gives in his life to reason, honor, and materialistic pleasure; Aristotle holds a somewhat analogous view which presents human beings as internally motivated toward lives in which the goods of the soul (knowledge and the virtues), the goods of the city (government and mutual regard), and external goods (physical and material safety and comfort) are all desired “by nature," albeit in different degrees.
Politics
Ancient political philosophy began in the 5th century BCE, influenced by several historical factors: (i) the beginning of historical-political awareness of the differences between Greek and Asiatic societies, and between the Spartan and Athenian city-states; (ii) the practice of devising political constitutions for colony states; (iii) the establishment of Pythagorean utopian-religious communities, which were organized with the goal of instilling virtue in the citizens; (iv) the widespread institution of slavery, generally regarded as necessary to the ancient economy; (v) the prevalence of warfare between Greeks and Persians, and among the Greeks, particularly Sparta and Athens; (vi) the sharp distinction between the social roles of men and women, women being denied both higher education and political rights; (vii) the beginning of political ideologies in Athens, especially between “radical democrats” who sought to expand and “conservatives” who sought to restrict democratic institutions and the political influence of the working class.
Modern scholars tend to identify Atomists and the Sophists with ancient democratic, Plato and Aristotle with ancient aristocratic political theory, though all of these thinkers rejected the claims of conventional aristocrats to political legitimacy (with the possible exception of ethical relativists). But insofar as both Atomists and Sophists rejected the idea of an objective ethics that might guide the formation of political order—the goal of the polis being then to protect and promote human virtue and fulfillment—they also rejected the idea that politics was anything more than the product of social agreements, which might have arisen in some way naturally, but certainly were also due to violence, and in any case now were subject to debate and re-organization based on choice and persuasion (logos), rather than tradition or force. For the Atomists and some Sophists, this led to the formation of a proto-Hobbesian social contract model of justice, which conferred political legitimacy insofar as the laws protected people against each other’s predations. The Atomists went further than most Sophists by rejecting the legitimacy of slavery, and insisting on egalitarian political arrangements, though as we have seen they did not think a wise person would devote their energies to public life or matters of justice. Sophists also identified with democratic, “open” societies, which would allow space for political debate and persuasion, their claim to expertise, to “the political craft” (techne politike). Some Sophists, however, influenced by the ideal of the “tyrannical life,” argued that the natural political order was one in which an aristocratic few or tyrannical one ruled over and exploited the democratic many, i.e. that hierarchy and competition, not equality and cooperation, was more "natural" to human society.
The Socratic tradition, embracing the idea of an objective, teleological ethics, rejected both democratic and conventional aristocratic political theories, in favor of what might be called a “virtue-oriented” or utopian politics, which included a strong element of “critical theory.” Plato, in particular, criticizes the potentially harmful effect on both thought/false beliefs and character/bad values of growing up in morally defective societies—the instilling of dogmatism and aggression in military societies, of greed in money-loving societies, of narcissism and lack of discipline in anarchistic democratic societies, of fear and violence in tyrannical societies, and of “political mythologies” that distort political and self-knowledge in each. In his Republic, Plato envisions a “high utopian” society governed by male and female philosophers, who live communistically in service to the state and the pursuit of knowledge, and who impose a strict moral and religious discipline on the other citizens. In his Laws, he envisions a “low utopian” society, governed by property-owning aristocrats, though even in this model there is a role for philosophical wisdom. Aristotle likewise distinguishes between a “utopian” virtuous society, governed by a cultured aristocracy, and a sound “republican” society, a democracy of the middle (i.e. propertied) class. But insofar as both Plato and Aristotle rejected the idea of value-pluralism, represented in ancient thought by the Atomists and Sophistic relativists, they both support the idea that the state has as its goal not only protecting and advancing the material well-being of the citizens, but even more their moral and intellectual improvement. For Plato, this can only be achieved within an authoritarian, aristocratic form of government, which allows and promotes freedom of thought only within the ruling philosophical elite; for Aristotle, this can be achieved to some degree within a moderate democracy, which allows freedom of discussion and lifestyles, though Aristotle accepts, as Plato does not, the conventional ancient institutions of slavery and male/female social roles.