Also found in: Wikipedia.


(ärsĕs'ĭlā`əs), c.316–c.241 B.C., Greek philosopher of Pitane in Aeolis. He was the principal figure of the Middle Academy. Despite his position in the AcademyAcademy,
school founded by Plato near Athens c.387 B.C. It took its name from the garden (named for the hero Academus) in which it was located. Plato's followers met there for nine centuries until, along with other pagan schools, it was closed by Emperor Justinian in A.D. 529.
..... Click the link for more information.
, his teachings diverged from Platonic doctrine. By emphasizing the doubt expressed by Socrates as to the possibility of gaining knowledge, he took a position comparable to that of the Skeptics (see skepticismskepticism
[Gr.,=to reflect], philosophic position holding that the possibility of knowledge is limited either because of the limitations of the mind or because of the inaccessibility of its object. It is more loosely used to denote any questioning attitude.
..... Click the link for more information.
). He argued that knowledge and opinion could not be distinguished from each other, so that what anyone claims to know may be more or less probable but not certain. In denying the possibility of certainty he was a major opponent of the Stoics (see StoicismStoicism
, school of philosophy founded by Zeno of Citium (in Cyprus) c.300 B.C. The first Stoics were so called because they met in the Stoa Poecile [Gr.,=painted porch], at Athens, a colonnade near the Agora, to hear their master Zeno lecture.
..... Click the link for more information.
). Arcesilaus indirectly influenced CarneadesCarneades
, 213–129 B.C., Greek philosopher, b. Cyrene. He studied at Athens under Diogenes the Stoic, but reacted against Stoicism and joined the Academy, where he taught a skepticism similar to that of Arcesilaus.
..... Click the link for more information.
 and his school.


See A. A. Long, The Hellenistic Philosophers (2 vol. 1987).

References in classic literature ?
Peneleos, Leitus, Arcesilaus, Prothoenor, and Clonius were captains of the Boeotians.
Three main ancient medical 'schools of thought' have been identified: the 'dogmatics' (followers of Aristotle and the Stoics), who emphasized grand theories and deductive, normative science; the 'empirics' (followers of Academic Skepticism, itself originating with Arcesilaus [late 4th-mid3rd centuries BCE]), who favoured inductive, descriptive science (what we might call associationism); and the 'methodics' (followers of Greek Skepticism, itself founded by Pyrrho [mid 4th-late 3rd centuries BCE]), who rejected scientific theory altogether in order to concentrate upon practice (Temkin 1953: 218).
Ancient scepticism' is a term that standardly encompasses two philosophical traditions stretching from the third century BCE to approximately the second century CE: Pyrrhonism, named after its eponymous founder Pyrrho of Elis (360-270 BCE), and Academic scepticism, a sceptical movement which arose in the Platonic Academy around 268 BCE, when Arcesilaus of Pitane (316/5-241/0) became its head.
82) The ancient Skeptics, Arcesilaus and Carneades in particular, however, showed clearly that no subjective impression purporting to reveal anything about the world beyond consciousness can bear its own warrant.
If there should ever be anyone who could argue pro and contra on all subjects, in the Aristotelian manner, and with knowledge of Aristotle's rules deliver two opposing speeches in every case, or should argue, in the manner of Arcesilaus and Carneades, against every thesis, anyone who combined that methodology and training with this rhetorical experience and practice of speaking [which I mentioned before] would be the only true and perfect orator.
13) Later biographical sources, although not always trustworthy, suggest numerous teacher-student relationships of a pederastic nature: the philosophers Parmenides and Zeno, Xenocrates and Polemon, Polemon and Crates, Crantor and Arcesilaus, the sculptors Pheidias and Agoracritus of Paros, the physician Theomedon and Eudoxus of Cnidus.
Philosophandi rationem Academicam, quam tenuit Carneades, eandem fere fuisse, quam secutus est Arcesilaus, assensus introducta suspensione, rerum nixa incertitudine .
Sternbach), although it is there attributed to a different philosopher, the third-century BC Academic Arcesilaus, who according to Diogenes Laertius iv.
Developments in the Academy from the time of Arcesilaus to that of Carneades and his successors tend to be classified under two heads: scepticism and probabilism.
48) The thesis is attributed to Carneades by Sextus Empiricus (Against the Professors 7, 159-65), and can be traced back to Arcesilaus (Cicero, Academica 2.
Chapter 3 looks at Arcesilaus, the first head of the Academy to turn that school in (what we may retrospectively call) a skeptical direction; Arcesilaus emerges as a practitioner of suspension of judgment--not as someone who merely aimed to show that his Stoic opponents were committed to it--and therefore philosophically much closer to Sextus than Pyrrho was.