(urote the Octaeteris. Several ancient writers attribute to him the
invention or introduction of an imiprovement upon the Octaeterides of his predecessors. After
a time, he came back to Athens with a band of pupils, having in the mean time taught
philosophy in Cyzicum and the Propontis : he chose Athens, Laertius says, for the purpose of
vexing Plato, at one of whose symposia he introduced the fashion of the guests reclining in a
semicircle; and Nicomachus (he adds), the son of Aristotle, reports him to have said that
pleasure was a good. So much for Laertius, who also refers to some decree which was made in
honour of Eudoxus, names his son and daughters, states him to have written good works on
astronomy and geometry, and mentions the curious way in which the bull Apis told his fortune
when he was in Egypt. Eudoxus died at the age of fifty-three. Phanocritus wrote a work upon
Eudoxus (
The fragmentary notices of Eudoxus are numerous. Strabo mentions him frequently, and states
(ii. p. 119, xvii. p. 806) that the observatory of Eudoxus at Cnidus was existing in his
time, from which he was accustomed to observe the star Canopus. Strabo also says that he
remained thirteen years in Egypt, and attributes to him the introduction of the odd quarter
of a day into the value of the year. Pliny (Qu. Nat. 7.3) states him to
have first brought the motions of the planets (a theory on this subject) from Egypt into
Greece. Aristotle (in Arenar.) says he made the dia. meter of the sun nine times as great as that of the
moon. Vitruvius (
But all we positively know of Eudoxus is from the poem of ARATUS
and the commentary of Hipparchus upon it. From this commentary we learn that Aratus was not
himself an observer, but was the versifier of the Hist. Astr. Anc. vol. i. p. 107) has given a full
account of the comparison made by Hipparchus of Aratus with Eudoxus, and of both with his own
observations. He cannot bring himself to think that Eudoxus knew anything of geometry, though
it is on record that he wrote geometrical works, in spite of the praises of Proclus, Cicero,
Ptolemy, Sextus Empiricus (who places him with Hipparchus), &c., &c. Eudoxus, as
cited by Hipparchus, neither talks like a geometer, nor like a person who had seen the
heavens he describes: a bad globe, constructed some centuries before his time in Egypt,
might, for anything that appears, have been his sole authority. But supposing, which is
likely enough, that he was the first who brought any globe at all into Greece, it is not much
to be wondered at that his reputation should have been magnified. As to what Proclus says of
his geometry, see EUCLEIDES.
Rejecting the Bibl. Graec. vol.
iv. p. 12), we have the following works, all lost, which he is said to have written :
Mentioned by Proclus and Laertius, which is not, however, to be taken as the title of a
work:
Fabric. Bibl. Graec. vol iv. p. 10, &c.; Weidler, Hist. Astron.;
Hist. de l'Astron. Anc. vol. i.; Hipparchus, Comment. in
Aratum ;Böhmer, Dissertatio de Eudoxo
Cnidio, Helmstad. 1715; Ideler, in the