Heisenberg uncertainty principle See QUANTUM. MECHANIC. Hellenistic philosophy, the philosophical systems of the Hellenistic age (323–30 B.C., although 311–87 B.C. better defines it as a philosophical era), notably Epicureanism, Stoicism, and Skepticism. These all emerged in the generation after Aristotle’s death (322 B.C.), and dominated philosophical debate until the first century B.C., during which there were revivals of traditional Platonism and of Aristotelianism. The age was one in which much of the eastern Mediterranean world absorbed Greek culture (was ‘Hellenized,’ hence ‘Hellenistic’), and recruits to philosophy flocked from this region to Athens, which remained the center of philosophical activity until 87 B.C. Then the Roman sack of Athens drove many philosophers into exile, and neither the schools nor the styles of philosophy that had grown up there ever fully recovered.
Very few philosophical writings survive intact from the period. Our knowledge of Hellenistic philosophers depends mainly on later doxography, on the Roman writers Lucretius and Cicero (both mid-first century B.C.), and on what we learn from the schools’ critics in later centuries, e.g. Sextus Empiricus and Plutarch. ‘Skeptic’, a term not actually current before the very end of the Hellenistic age, serves as a convenient label to characterize two philosophical movements. The first is the New Academy: the school founded by Plato, the Academy, became in this period a largely dialectical one, conducting searching critiques of other schools’ doctrines without declaring any of its own, beyond perhaps the assertion (however guarded) that nothing could be known and the accompanying recommendation of ‘suspension of judgment’ (epoche). The nature and vivacity of Stoicism owed much to its prolonged debates with the New Academy. The founder of this Academic phase was Arcesilaus (school head c.268– c.241); its most revered and influential protagonist was Carneades (school head in the mid-second century); and its most prestigious voice was that of Cicero (106–43 B.C.), whose highly influential philosophical works were written mainly from a New Academic stance. But by the early first century B.C. the Academy was drifting back to a more doctrinal stance, and in the later part of the century it was largely eclipsed by a second ‘skeptic’ movement, Pyrrhonism. This was founded by Aenesidemus, a pioneering skeptic despite his claim to be merely reviving the philosophy of Pyrrho, a philosophical guru of the early Hellenistic period. His neo-Pyrrhonism survives today mainly through the writings of Sextus Empiricus (second century A.D.), an adherent of the school who, strictly speaking, represents its post-Hellenistic phase. The Peripatos, Aristotle’s school, officially survived throughout the era, but it is not regarded as a distinctively ‘Hellenistic’ movement. Despite the eminence of Aristotle’s first successor, Theophrastus (school head 322–287), it thereafter fell from prominence, its fortunes only reviving around the mid-first century B.C. It is disputed how far the other Hellenistic philosophers were even aware of Aristotle’s treatises, which should not in any case be regarded as a primary influence on them. Each school had a location in Athens to which it could draw pupils. The Epicurean school was a relatively private institution, its ‘Garden’ outside the city walls housing a close-knit philosophical community. The Stoics took their name from the Stoa Poikile, the ‘Painted Colonnade’ in central Athens where they gathered. The Academics were based in the Academy, a public grove just outside the city. Philosophers were public figures, a familiar sight around town. Each school’s philosophical identity was further clarified by its absolute loyalty to the name of its founder – respectively Epicurus, Zeno of Citium, and Plato – and by the polarities that developed in interschool debates. Epicureanism is diametrically opposed on most issues to Stoicism. Academic Skepticism provides another antithesis to Stoicism, not through any positions of its own (it had none), but through its unflagging critical campaign against every Stoic thesis.
It is often said that in this age the old Greek political institution of the city-state had broken down, and that the Hellenistic philosophies were an answer to the resulting crisis of values. Whether or not there is any truth in this, it remains clear that moral concerns were now much less confined to the individual city-state than previously, and that at an extreme the boundaries had been pushed back to include all mankind within the scope of an individual’s moral obligations. Our ‘affinity’ (oikeiosis) to all mankind is an originally Stoic doctrine that acquired increasing currency with other schools. This attitude partly reflects the weakening of national and cultural boundaries in the Hellenistic period, as also in the Roman imperial period that followed it.
The three recognized divisions of philosophy were ethics, logic, and physics. In ethics, the central objective was to state and defend an account of the ‘end’ (telos), the moral goal to which all activity was subordinated: the Epicureans named pleasure, the Stoics conformity with nature. Much debate centered on the semimythical figure of the wise man, whose conduct in every conceivable circumstance was debated by all schools. Logic in its modern sense was primarily a Stoic concern, rejected as irrelevant by the Epicureans. But Hellenistic logic included epistemology, where the primary focus of interest was the ‘criterion of truth,’ the ultimate yardstick against which all judgments could be reliably tested. Empiricism was a surprisingly uncontroversial feature of Hellenistic theories: there was little interest in the Platonic-Aristotelian idea that knowledge in the strict sense is non-sensory, and the debate between dogmatists and Skeptics was more concerned with the question whether any proposed sensory criterion was adequate. Both Stoics and Epicureans attached especial importance to prolepsis, the generic notion of a thing, held to be either innate or naturally acquired in a way that gave it a guaranteed veridical status. Physics saw an opposition between Epicurean atomism, with its denial of divine providence, and the Stoic world-continuum, imbued with divine rationality. The issue of determinism was also placed on the philosophical map: Epicurean morality depends on the denial of (both physical and logical) determinism, whereas Stoic morality is compatible with, indeed actually requires, the deterministic causal nexus through which providence operates. See also DOXOGRAPHERS , EPICUREANISM , SKEPTICS , STOICIS. D.N.S.