Stoics and Stoic Philosophy. —The Stoic School was founded in 322 B.C. by Zeno of Cittium and existed till the closing of the Athenian schools (A.D. 429). (It took its name from the #gr Stoa poikile, the painted hall or colonnade in which the lectures were held.) Its history may be divided into three parts: (I) Ancient Stoicism; (2) Middle Stoicism; (3) New Stoicism. (I) Ancient Stoicism (322-204).—Zeno of Cittium (b. 366; d. in 280) was the disciple of Crates the Cynic and the Academicians Stilpo, Xenocrates, and Polemon. After his death (264), Cleanthes of Assium (b. 331; d. 232) became head of the School; Chrysippus of Soli (b. 280) succeeded and was scholarch till 204. These philosophers, all of Oriental origin, lived at Athens, where Zeno played a part in politics and were in communication with the principal men of their day. The Stoic doctrine, of which Zeno laid the foundations, was developed by Chrysippus in 705 treatises, of which only some fragments have been preserved. In addition to the principles accepted by all the thinkers of their age (the perception of the true, if it exist, can only be immediate; bodies alone exist; the wise man is self-sufficient; the political constitution is indifferent), derived from the Sophists and the Cynics, they base the entire moral attitude of the wise man (conformity to oneself and nature, indifference to external things on a comprehensive concept of nature, in part derived from Heraclitus, but inspired by an entirely new spirit. It is a belief in a universal nature which is at one and the same time Fate infallibly regulating the course of events (Greek: eimarmene, logos); Zeus, or providence, the external principle of finality adapting all other things to the needs of rational beings; the law determining the natural rules that govern the society of men and of the gods; the artistic fire, the expression of the active force which produced the world, one, perfect, and complete from the beginning, with which it will be reunited through the universal conflagration, following a regular and ever recurring cycle. The popular gods are different forms of this force, described allegorically in the myths. This view of nature is the basis of the optimism of the Stoic moral system: confidence in the instinctive faculties, which, in the absence of a perfect knowledge of the world, ought to guide man’s actions; and again, the infallible wisdom of the sage, which Chrysippus tries to establish by means of a dialectic derived from Aristotle and the Cynics. But this optimism requires them to solve the following problems: the origin of the passions and the vices; the conciliation of fate and liberty; the origin of evil in the world. On the last two subjects they propounded all the arguments, that were advanced later up to the time of Leibniz.
(2) Middle Stoicism (second and first centuries B.C.).—Stoicism during this period was no longer a Greek School; it has penetrated into the Roman world, and became, under the influence of Scipio’s friend, Panaetius (185-112), who lived at Rome, and of Posidonius (135-40), who transferred the School to Rhodes, the quasi-official philosophy of Roman imperialism. Its doctrines were considerably modified, becoming less dogmatic in consequence of the criticism of the new Academician, Carneades (215-129). In Stoic morality Panaetius develops the idea of humanity. Posidonius is at once a savant, historian, geographer, mathematician, astronomer, and a mystic who, commenting on Plato’s works, revives his theories on the nature and destiny of the soul.
(3) New Stoicism (to A.D. 429).—The new Stoicism is more ethical and didactic. Science is no longer the knowledge of nature, but a kind of theological summa of moral and religious sentiments. Very little has been preserved of the short popular treatises and discourses, wherein, with a vivid style introduced under the influence of the Cynic diatribe, the philosopher endeavored to render his ethical principles practical. The letters of Seneca (2-68) to Lucilius, the conversations of Musonius (time of Nero), and of Epictetus (age of Domitian), the fragments of Hierocles (time of Hadrian), the memoirs of Marcus Aurelius (d. 180), give but an incomplete idea. Stoicism, which gradually disappeared as the official School, was the most important of the Hellenic elements in the semi-oriental religions of vanishing paganism.