William David Ross and Simon Hornblower
Thrasymachus of Chalcedon (fl. c. 430–400
William David Ross
Compiled an extant brief lexicon of difficult words in *Plato(1).
John Hedley Simon and Dirk Obbink
M. T. Griffin
A philosopher who accompanied *Brutus in his campaign against the triumvirs (see
Vicki Lynn Harper
Xenarchus taught at Alexandria, Athens, and Rome, and his acquaintances included the geographer Strabo and the emperor Augustus. He is best known for his critique of Aristotle’s fifth element, which constitutes the material of the heavenly bodies according to the De caelo. Xenarchus targeted in particular Aristotle’s reliance on direct correspondences between simple bodies and simple motions and suggested that the ontologically privileged fire “in its natural place” could perform circular motion and was thus a plausible candidate for the material constituent of the heavens. He made further contributions in physics, psychology, and ethics, but he does not seem to have shown the same interest in the Categories as his Peripatetic contemporaries.
Guy Cromwell Field and Simon Hornblower
Charles H. Kahn
Zeno (1), of Elea is portrayed by *Plato(1) (Prm. 127b) as the pupil and friend of *Parmenides, and junior to him by 25 years. Their fictional meeting with a ‘very young’ *Socrates (ibid.) gives little basis for firm chronology. We may conclude only that Zeno was active in the early part of the 5th cent.
The most famous of Zeno's arguments are the four paradoxes about motion paraphrased by *Aristotle (Ph. 6. 9), which have intrigued thinkers down to Bertrand Russell in our era. The Achilles paradox proposes that a quicker can never overtake a slower runner who starts ahead of him, since he must always first reach the place the slower has already occupied. His task is in truth an infinite sequence of tasks, and can therefore never be completed. The Arrow paradox argues that in the present a body in motion occupies a place just its own size, and is therefore at rest. But since it is in the present throughout its movement, it is always at rest. The Dichotomy raises the same issues about infinite divisibility as the Achilles; the Arrow and the Stadium (an obscure puzzle about the relative motion of bodies) are perhaps directed against the implicit assumption of indivisible minima.
Zeno (3) of *Tarsus, Stoic (See
William David Ross and Dirk Obbink
Zeno (6) of *Sidon, Stoic (See
John Francis Lockwood and Robert Browning
Zoïlus (Ζωΐλος) of *Amphipolis (4th cent.
(1) Against Isocrates. (2) Against Plato, favourably mentioned by Dion. Hal.Pomp. 1. (3) Against Homer (Καθʼ Ὁμήρου or Κατὰ τῆς Ὁμήρου ποιήσεως ‘Against Homer's poetry’ or perhaps Ὁμηρομάστιξ ‘scourge of Homer’, which became the author's nickname). This work was chiefly devoted to severe, though often captious, criticism of the poet's invention, of the credibility of incidents (e.g. Il.