One word more: not long ago an Eclectic school was introduced by Potamo of Alexandria,Certainly not the same as the person mentioned by Porphyry in his Life of Plotinus, 9, 11, for Polemo, not Potamo, is the correct form of the name in that place. Potamo is said by Suidas (s.v. Ποτάμων Ἀλ.) to have lived shortly before and contemporary with Augustus, whence it follows that Diogenes has taken without alteration a statement by an earlier writer who might truthfully say not long ago of the reign of Augustus. Suidas, whose article αἵρεσις agrees closely with our text, naturally omits πρὸ ὀλίγου., who made a selection from the tenets of all the existing sects. As he himself states in his Elements of Philosophy, he takes as criteria of truth (1) that by which the judgement is formed, namely, the ruling principle of the soul; (2) the instrument used, for instance the most accurate perception. His universal principles are matter and the efficient cause, quality, and place; for that out of which and that by which a thing is made, as well as the quality with which and the place in which it is made, are principles. The end to which he refers all actions is life made perfect in all virtue, natural advantages of body and environment being indispensable to its attainment.

It remains to speak of the philosophers themselves, and in the first place of Thales.

Chapter 1. THALES (floruit circa 585 B.C., the date of the eclipse)

Herodotus, Duris, and Democritus are agreed that Thales was the son of Examyas and Cleobulina, and belonged to the ThelidaeNelidac, if Bywater’s emendation is correct. who are Phoenicians, and among the noblest of the descendants of Cadmus and Agenor. As Plato testifies, he was one of the Seven Sages. He was the first to receive the name of Sage, in the archonship of Damasias582 b.c. at Athens, when the term was applied to all the Seven Sages, as Demetrius of Phalerum mentions in his List of Archons. He was admitted to citizenship at Miletus when he came to that town along with Nileos, who had been expelled from Phoenicia. Most writers, however, represent him as a genuine Milesian and of a distinguished family.

After engaging in politics he became a student of nature. According to some he left nothing in writing; for the Nautical AstronomyCf. Simplicius, In Phys. i. 23, 29-33 d. attributed to him is said to be by Phocus of Samos. Callimachus knows him as the discoverer of the Ursa Minor; for he says in his Iambics: Who first of men the course made plain Of those small stars we call the Wain, Whereby Phoenicians sail the main.Greek mariners steered by the Great Bear, the Phoenicians by the Little Bear, as Ovid states, Tristia, iv. 3. 1, 2.. But according to others he wrote nothing but two treatises, one On the Solstice and one On the Equinox, regarding all other matters as incognizable. He seems by some accounts to have been the first to study astronomy,See Sir T. L. Heath, Aristarchus of Samos, pp. 12-23., the first to predict eclipses of the sun and to fix the solstices; so Eudemus in his History of Astronomy. It was this which gained for him the admiration of Xenophanes and Herodotus and the notice of Heraclitus and Democritus.

And some, including Choerilus the poet, declare that he was the first to maintain the immortality of the soul. He was the first to determine the sun’s course from solstice to solstice, and according to some the first to declare the size of the sun to be one seven hundred and twentieth part of the solar circle, and the size of the moon to be the same fraction of the lunar circle. He was the first to give the last day of the month the name of Thirtieth, and the first, some say, to discuss physical problems.

AristotleDe anima, A 2, 405 a 19. and Hippias affirm that, arguing from the magnet and from amber, he attributed a soul or life even to inanimate objects. Pamphila states that, having learnt geometry from the Egyptians, he was the first to inscribe a right-angled triangle in a circle, whereupon he sacrificed an ox.

Others tell this tale of Pythagoras, amongst them Apollodorus the arithmetician. (It was Pythagoras who developed to their furthest extent the discoveries attributed by Callimachus in his Iambics to Euphorbus the Phrygian, I mean scalene triangles and whatever else has to do with theoretical geometry.i.e. a theory concerned with lines, γραμμαί, which of course include curves as well as straight lines.)

Thales is also credited with having given excellent advice on political matters. For instance, when Croesus sent to Miletus offering terms of alliance, he frustrated the plan; and this proved the salvation of the city when Cyrus obtained the victory. Heraclides makes Thales himselfNamely, in a dialogue. Cf. viii. 4. say that he had always lived in solitude as a private individual and kept aloof from State affairs.