Stoicism originated in the views of Socrates and Plato, as modified by Zeno of Citium (c. 335–c. 263 bce) and then by Chrysippus (c. 280–206 bce). It gradually gained influence in Rome, chiefly through Cicero (106–43 bce) and then later through Seneca the Younger (4 bce–65 ce). Remarkably, its chief proponents include both a slave, Epictetus (55–c. 135), and an emperor, Marcus Aurelius (121–180). This is a fine illustration of the Stoic message that what is important is the pursuit of wisdom and virtue, a quest that is open to all human beings because of their common capacity for reason, no matter what the external circumstances of their lives.

Today, the most common meaning of the word stoic is a person who remains unmoved by the sorrows and afflictions that distress the rest of humanity. This is an accurate representation of a Stoic ideal, but it must be placed in the context of a systematic approach to life. As noted above, Plato held that human passions and physical desires are in need of regulation by reason. The Stoics went farther: they rejected passions altogether as a basis for deciding what is good or bad. Although physical desires cannot simply be abolished, the wise person will appreciate the difference between wanting something and judging it to be good. Only reason can judge the goodness or badness of what is desired. If one is wise, he will identify himself with reason rather than with desire; hence, he will not hope for the satisfaction of physical desires or worry that they might not be satisfied. The Stoic will feel physical pain as others do, but he will know that physical pain leaves the true reasoning self untouched. The only thing that is truly good is to live in a state of wisdom and virtue. In pursuing such a life, one is protected from the play of fortune that afflicts those who aim at physical pleasure or material wealth, for wisdom and virtue are matters of the intellect and under the individual’s control. Moreover, if matters become too grim, there is always a way of ending the pain of the physical world. The Stoics were not reluctant to counsel suicide as a means of avoiding otherwise inescapable pain.

Perhaps the most important legacy of Stoicism, however, is its conviction that all human beings share the capacity to reason. This led the Stoics to a fundamental belief in equality, which went beyond the limited Greek conception of equal citizenship. Thus, Seneca claimed that the wise man will esteem the community of rational beings far above any particular community in which the accident of birth has placed him, and Marcus Aurelius said that common reason makes all individuals fellow citizens. The belief that the capacity to reason is common to all humans was also important because from it the Stoics drew the implication that there is a universal moral law, which all people are capable of appreciating (see natural law). The Stoics thus strengthened the tradition that regarded the universality of reason as the basis on which to reject ethical relativism.

The Epicureans

Although the modern use of the term stoic accurately represents at least a part of the Stoic philosophy, anyone taking the present-day meaning of epicure as a guide to the philosophy of Epicurus (341–270 bce) would go astray. True, the Epicureans regarded pleasure as the sole ultimate good and pain as the sole evil, and they did regard the more refined pleasures as superior, simply in terms of the quantity and durability of the pleasure they provided, to the coarser pleasures. To portray them as searching for these more refined pleasures by dining at the best restaurants and drinking the finest wines, however, is the reverse of the truth. By refined pleasures, Epicurus meant pleasures of the mind, as opposed to the coarse pleasures of the body. He taught that the highest pleasure obtainable is the pleasure of tranquillity, which is to be obtained by the removal of unsatisfied wants. The way to do this is to eliminate all but the simplest wants; these are then easily satisfied even by those who are not wealthy.

Epicurus developed his position systematically. To determine whether something is good, he would ask if it increased pleasure or reduced pain. If it did, it was good as a means; if it did not, it was not good at all. Thus, justice was good but merely as an expedient arrangement to prevent mutual harm. Why not then commit injustice when we can get away with it? Only because, Epicurus says, the perpetual dread of discovery will cause painful anxiety. Epicurus also exalted friendship, and the Epicureans were famous for the warmth of their personal relationships; but, again, they proclaimed that friendship is good only because of its tendency to create pleasure.

Both Stoic and Epicurean ethics were precursors of later trends in Western ethics: the Stoics of the modern belief in equality and the Epicureans of a utilitarian ethics based on pleasure (see below Utilitarianism). The development of these ethical positions, however, was dramatically affected by the spreading from the East of a new religion, Christianity, that was rooted in a Jewish conception of ethics as obedience to a divine authority. With the conversion of Emperor Constantine I (c. 280–337) to Christianity by 313 ce, the older schools of philosophy lost their sway over the thinking of the Roman Empire.

Ethics in the New Testament

The Apostle Matthew (5:17) reports Jesus as having said, in the Sermon on the Mount, that he came not to destroy the law or the prophets but to fulfill them. Indeed, when Jesus is regarded as a teacher of ethics, it is clear that he was more a reformer of the Hebrew tradition than a radical innovator. The Hebrew tradition had a tendency to place great emphasis on compliance with the letter of the law; the Gospel accounts of Jesus portray him as preaching against this “righteousness of the scribes and Pharisees,” championing the spirit of the law rather than the letter. This spirit he characterized as one of love, for God and for one’s neighbour. But since he was not proposing that the old teachings be discarded, he saw no need to develop a comprehensive ethical system. Christianity thus never really broke with the Jewish conception of morality as a matter of divine law to be discovered by reading and interpreting the word of God as revealed in the Scriptures.

This conception of morality had important consequences for the future development of Western ethics. The Greeks and Romans—and indeed thinkers such as Confucius—did not conceive of a distinctively moral realm of conduct. For them, everything that one did was a matter of practical reasoning, in which one could do either well or poorly. In the more legalistic Judeo-Christian view, however, falling short of what the moral law requires was a much more serious matter than, say, failing to do the household budgets correctly. This distinction between the moral and the nonmoral realms now affects every question in Western ethics, including the way the questions themselves are framed.

Another consequence of the retention of the basically legalistic stance of Jewish ethics was that from the beginning Christian ethics had to deal with the question of how to judge the person who breaks the law from good motives or keeps it from bad motives. The latter half of this question was particularly acute, because the Gospels describe Jesus as repeatedly warning of a coming resurrection of the dead at which time all would be judged and punished or rewarded according to their sins and virtues in this life (see Last Judgment). The punishments and rewards were weighty enough to motivate anyone who took this message seriously, and the warning was given added emphasis by the fact that the resurrection was not going to be long in coming. (Jesus said that it would take place during the lifetime of some of those listening to him.) This is therefore an ethics that invokes external sanctions as a reason for doing what is right. At the same time, it is an ethics that places love above mere literal compliance with the law. These two aspects do not sit easily together. Can one bring oneself to love God and neighbour in order to be rewarded with eternal happiness in another life?

The fact that Jesus and the Apostle Paul too believed in the imminence of the Second Coming led them to suggest ways of living that were scarcely feasible on any other assumption: taking no thought for the morrow, turning the other cheek, and giving away all one has. Even Paul’s preference for celibacy rather than marriage and his grudging acceptance of the latter on the assumption that “it is better to marry than to burn” makes some sense, once one grasps that he was proposing ethical standards for what he thought would be the last generation on earth. When the expected event did not occur and Christianity became the official religion of the vast and embattled Roman Empire, Christian leaders were faced with the awkward task of reinterpreting these injunctions in a manner more suited for a continuing society.

The new Christian ethical standards did lead to some changes in Roman morality. Perhaps the most vital change was a new sense of the equal moral status of all human beings. As mentioned earlier, the Stoics had been the first to elaborate this conception, grounding equality on the common capacity to reason. For Christians, humans are equal because they are all potentially immortal and equally precious in the sight of God. This caused Christians to condemn a wide variety of practices that had been accepted by both Greek and Roman moralists, including many related to the taking of innocent human life: from the earliest days Christian leaders condemned abortion, infanticide, and suicide. Even killing in war was at first regarded as wrong, and soldiers who had converted to Christianity refused to continue to bear arms. Once the empire became Christian, however, this was one of the inconvenient ideas that had to yield. Despite what Jesus had said about turning the other cheek, church leaders declared that killing in a “just war” was not a sin. The Christian condemnation of killing in gladiatorial games, on the other hand, had a more permanent effect. Finally, but perhaps most important, while Christian emperors continued to uphold the legality of slavery, the Christian church accepted slaves as equals, admitted them to its ceremonies, and regarded the granting of freedom to slaves as a virtuous, if not obligatory, act. This moral pressure led over several hundred years to the gradual disappearance of slavery in Europe.

The Christian contribution to improving the position of slaves can also be linked with the distinctively Christian list of virtues. As noted above, some of the virtues described by Aristotle—for example, greatness of soul—are quite contrary in spirit to Christian virtues such as humility. In general it can be said that, whereas the Greeks and Romans prized independence, self-reliance, magnanimity, and worldly success, Christians emphasized meekness, obedience, patience, and resignation. As the Greeks and Romans conceived virtue, a virtuous slave was almost a contradiction in terms; for Christians, however, there was nothing in the state of slavery that was incompatible with the highest moral character.