Stoicism is the term applied to a philosophical movement that dominated Greek and Roman thought from the 3rd century B.C. to the 3rd century A.D. Its central doctrines include self‐​discipline, natural law, resistance to tyranny, and an unconditional commitment to duty.

The name Stoic derives from the Stoa Poikilé, the colonnade in Athens where the movement was founded. The most important of the early Stoic philosophers are Zeno, the school’s founder—usually called Zeno of Citium to avoid confusion with Zeno of Elea, author of the famous paradoxes of motion—and Chrysippus, a logician who so thoroughly reworked Stoic doctrine as to earn the title of “second founder.” Unfortunately, the writings of these and other early Stoics are lost and must be reconstructed from ancient reports and quotations. Stoicism has thus had an influence on later thinkers primarily through the surviving writings of the later Stoics, particularly the Roman statesman Marcus Tullius Cicero, the playwright and imperial advisor Lucius Annaeus Seneca, and the Greek freedman Epictetus. Cicero, an adherent of the skeptical outlook of the New Academy, did not unconditionally accept the tenets of Stoic philosophy, but he is in substantial agreement with Stoic ethical and political doctrine, much of which he borrowed from the now‐​lost writings of Panaetius and Poseidonius. Seneca and Epictetus, by contrast, are fairly orthodox Stoics. Another influential Stoic author was the Roman Emperor Marcus Aurelius. Stoic philosophy also draws heavily on the views of such earlier thinkers as Heraclitus, Socrates, and the Cynics.

The central teaching of Stoic ethics is that nothing is desirable or valuable except virtue; hence, a Stoic will be unruffled by the vicissitudes of fortune so long as his personal honor remains intact. For example, a courageous warrior will concern himself with doing the best he can to save his city because that is his duty and because it is in his power, but will not really care about actually saving his city because that ultimately depends on fortune and is not his responsibility. Several arguments were offered for this position.

First, a wise person, it was felt, could be trusted never to be tempted away from virtue; but if anything other than virtue were valuable, such a good would be a potential rival to virtue and so the wise person’s commitment to virtue would not be reliable after all.

Second, our happiness is vulnerable to bad luck so long as we allow ourselves to care about things outside our power, whereas those who care only about their own attitudes and choices can never have their happiness frustrated. Third, each of us should attempt to be like a good stage actor, performing without complaint the part that has been assigned to us by God or Fate, regarded by the Stoics as a living and intelligent cosmic fire pervading and controlling the universe. Finally, although human beings start off with an instinctual attachment to their own self‐​preservation and natural functioning, and initially value reason only as an instrumental means to these more fundamental goals, should we develop and mature properly and become habituated to the use of reason, we will come to value reason as an end rather than as a means. The result is that our rational activity in orderly harmony with other people and with nature will entirely supersede our earlier concerns.

The Stoic ethical position entails a negative attitude toward the emotions. Emotions are not mere feelings, but involve cognitive judgments; in experiencing love, fear, anger, and so forth, we are committing ourselves to the judgment that certain external objects are good or bad. These judgments, however, are false because nothing is good but virtue, or bad but vice. Because a wise person will not endorse false judgments, in order to become wise, we must overcome all such emotions and be governed by reason alone. (The apparently unrealistic character of this advice is mitigated by the Stoics’ clarification that the emotions are to be identified not with our initial involuntary impressions, but with our assent to them as true judgments and as guides to action.)

In politics, the Stoics embraced the cosmopolitan doctrine that all human beings were citizens of a single natural community, governed by the natural law of reason that superseded local man‐​made statutes. In Cicero’s memorable formulation in On the Republic: “There will not be a different law at Rome and at Athens, or a different law now and in the future, but one law, everlasting and immutable, will hold good for all peoples and at all times.” Although Zeno seems to have interpreted this doctrine in an antinomian fashion, envisioning a utopian society free from such conventional institutions as law courts, temples, money, or constraints on sexual freedom, the later Stoics made a greater accommodation to traditional mores. Stoic writings in the Roman period defended private property and market exchange, holding that the protection of property rights was the central function of the state. Among Stoics, Roman law came to be interpreted as a reflection of natural law and Roman imperialism as the realization of the universal human community.

Nevertheless, the emergence of the Roman Empire from what had been a republic did not meet with Stoic approval. Although the Stoic conception of freedom is primarily a psychological one, Stoicism was nonetheless hostile to autocratic despotism and looked back with nostalgia to the pre‐​imperial days of participatory republicanism and the rule of law. Adherents of Stoicism are numbered among the assassins of Julius Caesar and the would‐​be assassins of the Emperor Nero.

Stoicism cast a long shadow on later thought. The apostle Paul came from Tarsus, a center of Stoic learning, and he frequently cited Stoic authors favorably. A forged correspondence between Paul and Seneca ensured the latter’s popularity among the early Christians, and such writers as Augustine and Boethius were responsible for incorporating a great deal of Stoic thought into Christian theology. In later centuries, Stoicism exercised a powerful influence on the development of classical liberalism through such works as John Locke’s Two Treatises of Government, Jean‐​Jacques Rousseau’s Discourses, Adam Smith’s Theory of Moral Sentiments, and the ethical writings of Immanuel Kant.

Of particular significance for the liberal tradition is the Stoic statesman Cato the Younger, whose intransigent defense of republican ideals earned him the enmity of Julius Caesar. To his 18th‐​century admirers, Cato was an apt symbol of resistance to despotism. George Washington had Joseph Addison’s play Cato performed at Valley Forge to inspire his troops. Anonymous tracts hostile to governmental power were often signed with the pseudonym Cato, among the most famous of which were Cato’s Letters by John Trenchard and Thomas Gordon and several Anti‐​Federalist pamphlets (criticizing the proposed U.S. Constitution) attributed to New York Governor George Clinton.

Further Readings

Cicero, Marcus Tullius. On Duties. E. M. Atkins and Miriam Griffin, eds. Cambridge: Cambridge University Press, 1991.

———. The Republic and the Laws. Jonathan Powell and Niall Rudd, eds. Oxford: Oxford University Press, 1998.

Epictetus. The Discourses as Reported by Arrian. Fragments. Encheiridion. 2 vols. W. A. Oldfather, ed. Cambridge, MA: Harvard University Press, 1998.

Erskine, Andrew. The Hellenistic Stoa: Political Thought and Action. Ithaca, NY: Cornell University Press, 1990.

Long, A. A., and D. N. Sedley. The Hellenistic Philosophers: Volume I. Translations of the Principal Sources with Philosophical Commentary. Cambridge: Cambridge University Press, 1987.

Schofield, Malcolm. The Stoic Idea of the City. Cambridge: Cambridge University Press, 1991.

Seneca. Moral and Political Essays. John M. Cooper and J. F. Procopé, eds. Cambridge: Cambridge University Press, 1995.