ARCHYTAS
213
told that Plato ‘ explained {ela^y-qa-aTo) to Leodamas of Thasos
the method of inquiry by analysis ’ 1 ; Proclus’s account is
fuller, stating that the finest method for discovering lemmas
in geometry is that ‘ which by means of analysis carries the
thing sought up to an acknowledged principle, a method
which Plato, as they say, communicated to Leodamas, and
by which the latter too is said to have discovered many
things in geometry’. 2 Nothing more than this is known of
Leodamas, but the passages are noteworthy as having given
rise to the idea that Plato invented the method of mathe
matical analysis, an idea which, as we shall see later on, seems
nevertheless to be based on a misapprehension.
Archytas of Taras, a Pythagorean, the friend of Plato,
flourished in the first half of the fourth century, say 400 to
365 B.c. Plato made his acquaintance when staying in Magna
Graecia, and he is said, by means of a letter, to have saved
Plato from death at the hands of Dionysius. Statesman and
philosopher, he was famed for every sort of accomplishment.
He was general of the forces of his city-state for seven years,
though ordinarily the law forbade any one to hold the post
for more than a year; and he was never beaten. He is
said to have been the first to write a systematic treatise oil
mechanics based on mathematical principles. 3 Vitruvius men
tions that, like Archimedes, Ctesibius, Nymphodorus, and
Philo of Byzantium, Archytas wrote on machines 4 ; two
mechanical devices in particular are attributed to him, one
a mechanical dove made of wood which would fly, 5 the
other a rattle which, according to Aristotle, was found useful
to £ give to children to occupy them, and so prevent them
from breaking things about the house (for the young are
incapable of keeping still) ’. 6
We have already seen Archytas distinguishing the four
mathematical sciences, geometry, arithmetic, sphaeric (or
astronomy), and music, comparing the art of calculation with
geometry in respect of its relative efficiency and conclusive
ness, and defining the three means in music, the arithmetic,
] Diog. L. iii. 24. 2 Proclus on Eucl. I, p. 211. 19-28.
3 Diog. L. viii. 79-88.
4 Vitruvius, De architectural, Praef. vii. 14.
5 Gellius, x. 12, 8, after Favorinus (Vors. i 3 , p. 325. 21-9).
0 Aristotle, Politics, E (©). 6, 1340 b 26.