THE ELEMENTS 
321 
It will be well to dispose of the smaller names in this 
list before taking up Eudoxus, the principal subject of 
this chapter. The name of Amyclas should apparently be 
Amyntas, 1 although Diogenes Laertius mentions Amyclos of 
Heraclea in Pontus as a pupil of Plato 2 and has elsewhere an 
improbable story of one Amyclas, a Pythagorean, who with 
Clinias is supposed to have dissuaded Plato from burning the 
works of Democritus in view of the fact that there were 
many other copies in circulation. 3 Nothing more is known 
of Amyntas, Theudius, Athenaeus and Hermotimus than what 
is stated in the above passage of Proclus. It is probable, 
however, that the propositions, &c., in elementary geometry 
which are quoted by Aristotle were taken from the Elements 
of Theudius, which would no doubt be the text-book of the 
time just preceding Euclid. Of Menaechmus and Dinostratus 
we have already learnt that the former discovered conic 
sections, and used them for finding two mean proportionals, 
and that the latter applied the quadratrix to the squaring 
of the circle. Philippus of Medina (vulg. Mende) is doubtless 
the same person as Philippus of Opus, who is said to have 
revised and published the Laws of Plato which had been left 
unfinished, and to have been the author of the Epinomis. 
He wrote upon astronomy chiefly; the astronomy in the 
Epinomis follows that of the La/tvs and the Timaeus; but 
Suidas records the titles of other works by him as follows: 
On the distance of the sun and moon, On the eclipse of the 
moon, On the size of the sun, the moon and the earth, On 
the planets. A passage of Aetius 4 and another of Plutarch 5 
alluding to his proofs about the shape of the moon may 
indicate that Philippus was the first to establish the complete 
theory of the phases of the moon. In mathematics, accord 
ing to the same notice by Suidas, he wrote Arithmetica, 
Means, On polygonal numbers, Gyclica, Optics, Enoptrica 
(On mirrors); but nothing is known of the contents of these 
works. 
* 
1 See hid. Hercul., ed. B cheler, Ind. Schol. Gryphisw., 1869/70, col. 
6 in. 
2 Diog. L. iii. 46. 3 Ih. ix. 40. 
4 Dox. Gr., p. 360. 
6 Non posse suaviter vivi secundum Epicurum, c. 11, 1093 E, 
Y 
1623