Hellenistic and Roman philosophy

Stoicism

The Stoic system was created by Zeno of Citium (c. 335–c. 263 bce), who went to Athens as a merchant. He stayed at Athens, heard the lectures of various philosophers, and—after he had elaborated his own philosophy—began to teach in a public hall, the Stoa Poikile (hence the name Stoicism).

Zeno’s thought comprised, essentially, a dogmatized Socratic philosophy with added ingredients derived from Heracleitus (c. 540–c. 480 bce). The basis of human happiness, he said, is to live “in agreement” with oneself, a statement that was later replaced by the formula “to live in agreement with nature.” The only real good for a human being is the possession of virtue; everything else—wealth or poverty, health or illness, life or death—is completely indifferent. All virtues are based exclusively on right knowledge, self-control (sōphrosynē) being the knowledge of the right choice, fortitude the knowledge of what must be endured and what must not, and justice the right knowledge “in distribution.” The passions, which are the cause of all evil, are the result of error in judging what is a real good and what is not. Because it is difficult to see, however, why murder, fraud, and theft should be considered evil if life and possessions are of no value, the doctrine was later modified to distinguish between “preferable things,” such as having the necessities of life and health, “completely indifferent things,” and “anti-preferable things,” such as lacking the necessities of life or health—while insisting still that the happiness of the truly wise person could not be impaired by illness, pain, hunger, or any deprivation of external goods. In the beginning, Zeno also insisted that an individual is either completely wise, in which case he would never do anything wrong and would be completely happy, or he is a fool. Later he made the concession, however, that there are people who are not completely wise but who are progressing toward wisdom. Although these people might even have true insight, they are not certain that they have it, whereas the truly wise person is also certain of having true insight. The world is governed by divine logos—a word originally meaning “word” or “speech,” then (with Heracleitus) a speech that expresses the laws of the universe, then (finally) “reason.” This logos keeps the world in perfect order. Human beings can deviate from or rebel against this order, but, by doing so, they cannot disturb it but can only do harm to themselves.

Zeno’s philosophy was further developed by Cleanthes (c. 331–c. 232 bce), the second head of the school, and by Chrysippus (c. 280–c. 206 bce), its third head. Chrysippus elaborated a new kind of logic, which did not receive much attention outside the Stoic school until recent times. This “propositional logic” has been hailed by some logicians as superior to the “conceptual logic” of Aristotle. Panaetius of Rhodes (c. 180–109 bce) adapted Stoic philosophy to the needs of the Roman aristocracy, whose members then governed the Western world, and made a great impression on some of the leading figures of the time, who tried to follow his moral precepts. In the following century, a time of civil war, slave rebellions, and the decay of the Roman Republic, Poseidonius of Apamea (c. 135–c. 51 bce), who was also one of the most brilliant historians of all times, taught that the Stoic takes a position above the rest of humankind, looking down on its struggles as on a spectacle. In the period of the consolidation of the empire, Stoicism became the religion of the republican opposition. The most famous Stoic was the younger Cato (95–46 bce), who committed suicide after the victory of Julius Caesar (c. 100–44 bce). It was also the guiding philosophy of Seneca the Younger (c. 4 bce–65 ce), the educator and (for a long time) the adviser of the emperor Nero (37–68), who tried to keep Nero on the path of virtue but failed and finally was forced to commit suicide on Nero’s orders. Despite the oddities of Zeno’s original doctrine, Stoicism gave consolation, composure, and fortitude in times of trouble to many proud individuals to the end of antiquity and beyond.

Epicureanism

The thought of Zeno’s contemporary Epicurus (341–270 bce) also constituted a philosophy of defense in a troubled world. Nevertheless, it has been considered—in many respects justly—the opposite of Zeno’s thought. Whereas Zeno proclaimed that the wise person tries to learn from everybody and always acknowledges his debt to earlier thinkers, Epicurus insisted that everything he taught was original to himself, though it is obvious that his physical explanation of the universe is a simplification of Democritus’s atomism. And whereas the Stoics had taught that pleasure and pain are of no importance for a person’s happiness, Epicurus made pleasure the very essence of a happy life. Moreover, the Stoics from the beginning had acted as advisers of kings and statesmen. Epicurus, on the other hand, lived in the retirement of his famous garden, cultivating intimate friendships with his adherents but warning against participation in public life. The Stoics believed in divine providence; Epicurus taught that the gods pay no attention whatever to human beings. Yet despite these contrasts, the two philosophies had some essential features in common. Although Epicurus made pleasure the criterion of a good life, he was far from advocating dissolution and debauchery; he insisted that it is the simple pleasures that make a life happy. When, in his old age, he suffered terrible pain from prostatitis, he asserted that philosophizing and the memory and love of his distant friends made pleasure prevail even then. Nor was Epicurus an atheist. His Roman admirer the poet Lucretius (flourished 1st century bce), in his poem De rerum natura (On the Nature of Things), praised Epicurus enthusiastically as the liberator of humankind from all religious fears; Epicurus himself affirmed that this had been one of the aims of his philosophy. But although he taught that the gods are much too superior to trouble themselves with the affairs of mortals, he said—and, as his language clearly shows, sincerely believed—that it is important for human beings to look at the gods as perfect, since only in this way could humans approach perfection. It was only in Roman times that people began to misunderstand Epicureanism, holding it to be an atheistic philosophy justifying a dissolute life, so that a person could be called “a swine from the herd of Epicurus.” Seneca, however, recognized the true nature of Epicureanism; in his Epistulae morales (Moral Letters) he deliberately interspersed maxims from Epicurus through his Stoic exhortations.

Skepticism

There was still another Hellenistic school of philosophy, Skepticism, which was initiated by another of Zeno’s contemporaries, Pyrrhon of Elis (c. 360–c. 272 bce), and was destined to become of great importance for the preservation of detailed knowledge of Hellenistic philosophy in general. Pyrrhon had come to the conviction that no one can know anything for certain, nor can he ever be certain that the things he perceives with his senses are real and not illusory. Pyrrhon is said to have carried the practical consequences of his conviction so far that, when walking in the streets, he paid no attention to vehicles and other obstacles, so that his faithful disciples always had to accompany him to see that he came to no harm. Pyrrhon’s importance for the history of philosophy lies in the fact that one of the later adherents of his doctrine, Sextus Empiricus (flourished 3rd century ce), wrote a large work, Pros dogmatikous (“Against the Dogmatists”), in which he tried to refute all of the philosophers who held positive views, and in so doing he quoted extensively from their works, thus preserving much that would otherwise have been lost. It is a noteworthy fact that the British empiricists of the 18th century, such as David Hume (1711–76), as well as Immanuel Kant (1724–1804), derived most of their knowledge of ancient philosophy from Sextus Empiricus.

Neo-Pythagoreanism and Neoplatonism

All of the philosophical schools and sects of Athens that originated in the 4th century bce continued into late antiquity, most of them until the emperor Justinian I (483–565 ce) ordered them closed in 529 because of their pagan character. Within this period of nearly 1,000 years, only two new schools emerged, neo-Pythagoreanism and Neoplatonism. Both were inspired by early Greek philosophy, though only the latter would become historically important. Neoplatonism was established by Ammonius Saccas (flourished early 3rd century ce), who had been brought up as a Christian but had abandoned his religion for the study of Plato. Because Ammonius wrote nothing, his philosophy is known only through his famous disciple Plotinus (205–270). But Plotinus did not publish anything either. His philosophy is known through the Enneads, a collection of his writings arranged by his disciple Porphyry (234–305), who also wrote a biography of Plotinus.

Although the philosophy of Plotinus (and Ammonius) was derived from Plato, it used many philosophical terms first coined by Aristotle and adopted some elements of Stoicism as well. Yet it was essentially a new philosophy, agreeing with the religious and mystical tendencies of its time. Plotinus assumed the existence of several levels of Being, the highest of which is that of the One or the Good, which are identical but indescribable and indefinable in human language. The next lower level is that of nous, or pure intellect or reason; the third is that of the soul or souls. There then follows the world perceived by the senses. Finally, at the lowest level there is matter, which is the cause of all evil. The highest bliss available to human beings is union with the One, or the Good, which is attained by contemplation and purification. That this is not a lasting state attained once and for all—like the status of the Stoic wise man, who was supposed never to lose his wisdom—is shown by the fact that Porphyry, in his biography, said that Plotinus had experienced this supreme bliss seven times in his life, whereas he, Porphyry, had experienced it only once.

The further history of Neoplatonism is extremely complicated. While Porphyry had emphasized the ethical element in Plotinus’s philosophy, his disciple in Syria, Iamblichus of Chalcis (c. 250–c. 330), mingled Neoplatonism with neo-Pythagoreanism, writing on the Pythagorean way of life and on number theory. Above all, he multiplied the levels of Being, or the emanations from the One, which enabled him to incorporate the traditional Greek gods into his system. Another branch of the school was founded in Pergamum, in western Asia Minor, by Iamblichus’s student Aedesius (died 355), who, with his own disciple Maximus of Ephesus (died 370), tried to revive the ancient Greek mystery religions, such as Orphism. All of these developments became of great importance in the 4th century, when the emperor Julian the Apostate (c. 331–363) attempted to revive paganism. In the following century the Athenian school reached a new high point when Proclus (c. 410–485) combined the ideas of his predecessors into a comprehensive system. When Justinian closed all of the philosophical schools in Athens in 529, however, a branch continued to exist in Alexandria. The Athenian Neoplatonists found refuge at the court of the Persian king Khosrow I (died 579), and in 535 they were permitted to return to Athens. But gradually pagan philosophy as such died out, though it continued to influence the development of Christian philosophy and theology.