POSIDONIUS, a distinguished Stoic philosopher, the most learned man of his time (c. 130-50 b.c.) and perhaps of all the school; by birth a Syrian from Apamea, a pupil of Panaetius, he spent after his teacher’s death many years in travel and scientific researches in Spain (particularly at Gades), Africa, Italy, Gaul, Liguria, Sicily, and on the eastern shores of the Adriatic. When he settled as a teacher at Rhodes his fame attracted numerous scholars; next to Panaetius he did most, by writings and personal intercourse, to spread Stoicism in the Roman world; he became well known to many of the leading men, as Marius, Rutilius Rufus, Pompey, and Cicero. The last-named studied under him (78-77 b.c.), and speaks as his warm admirer and personal friend....
Strabo mentions him as a contemporary. The date of his birth has not been fixed; it may have been 135, 130, or 125 B. c.; according to Lucian, he lived to be eighty-four. He visited Rome— e.g., in 86 b.c. on an embassy; but it is doubtful if he ever resided there as a teacher. His works, now lost, were written in an attractive style and proved a mine of information to later writers. The titles and subjects of more than twenty of them are known. In common with other Stoics of the middle period, he displays eclectic tendencies. His admiration for Plato led him to write a commentary on the TimaeiLS ; in another way it is shown by important modifications which he made in psychological doctrine. Unquestionably more of a polymath than a philosopher, he appears to us uncritical, or credulous even, and superficial. But at the time his spirit of inquiry provoked Strabo’s criticism as something alien to the school (τό αίτιολογικάη κal το άριστοτΟαζον , ô'irep έκκΧίνουσιν οί ημeτepoι). In natural science he took a genuine interest, as his contributions to geography, natural history, mathematics, and astronomy sufficiently attest. He sought to determine the distance and magnitude of the sun, to calculate the diameter of the earth and the influence of the moon on the tides. His history of the period from 146 to 88 b.c., in fifty-two books, must have been a valuable storehouse of facts. Cicero, who submitted to his criticism the memoirs which he had written in Greek of his consulship, made use of writings of Posidonius in De Natura Deorum, b. ii., and De Divinatione, b. i., and the author of the pseudoAristotelian treatise De Mundo also borrowed from him.
Zeller, Philosophie der Griechen, iii. 1, 570-584 (in Eng. trans., Eclecticism, 56- 70); C. Müller, Fragmenta Historicorum Graecorum, iii. 245-296; J. Bake, Posidoni i Rhodii Reliquiae, Leyden, 1810 (a valuable monograph); R. Scheppig, De Posidonio rerum gentium terrarum scriptore, Berlin, 1869; R. Hirzel, Untersuchungen zu Ciceros philosophischen Schriften, i. 191 sq. ; ii. 257 sq., 325 sq., 477-535, 756-789; iii. 342-378 (Leipsic, 1877). See Stoicism.
[489 words — estimated reading time: 3 minutes]