[179] Anaxag. Fr. 19, Schaub.; Sextus Empiric. adv. Mathem. vii. 91-140; Cicero, Academ. i. 12.
Anaxagoras remarked that the contrast between black and white might be made imperceptible to sense by a succession of numerous intermediate colours very finely graduated. He is said to have affirmed that snow was really black, notwithstanding that it appeared white to our senses: since water was black, and snow was only frozen water (Cicero, Academ. iv. 31; Sext. Empir. Pyrrhon. Hypotyp. i. 33). “Anaxagoras non modo id ita esse (sc. albam nivem esse) negabat, sed sibi, quia sciret aquam nigram esse, unde illa concreta esset, albam ipsam esse ne videri quidem.” Whether Anaxagoras ever affirmed that snow did not appear to him white, may reasonably be doubted: his real affirmation probably was, that snow, though it appeared white, was not really white. And this affirmation depended upon the line which he drew between the fact of sense, the phenomenal, the relative, on one side — and the substratum, the real, the absolute, on the other. Most philosophers recognise a distinction between the two; but the line between the two has been drawn in very different directions. Anaxagoras assumed as his substratum, real, or absolute, the Homœomeries — numerous primordial varieties of matter, each with its inherent qualities. Among these varieties he reckoned water, but he did not reckon snow. He also considered that water was really and absolutely black or dark (the Homeric μέλαν ὕδωρ) — that blackness was among its primary qualities. Water, when consolidated into snow, was so disguised as to produce upon the spectator the appearance of whiteness; but it did not really lose, nor could it lose, its inherent colour. A negro covered with white paint, and therefore looking white, is still really black: a wheel painted with the seven prismatic colours, and made to revolve rapidly, will look white, but it is still really septi-coloured: i.e. the state of rapid revolution would be considered as an exceptional state, not natural to it. Compare Plato, Lysis, c. 32, p. 217 D.
The doctrines of Anaxagoras were regarded as offensive and impious.
Anaxagoras, residing at Athens and intimately connected with Perikles, incurred not only unpopularity, but even legal prosecution, by the tenor of his philosophical opinions, especially those on astronomy. To Greeks who believed in Helios and Selênê as not merely living beings but Deities, his declaration that the Sun was a luminous and fiery stone, and the Moon an earthy mass, appeared alike absurd and impious. Such was the judgment of Sokrates, Plato, and Xenophon, as well as of Aristophanes and the general Athenian public.[180] Anaxagoras was threatened with indictment for blasphemy, so that Perikles was compelled to send him away from Athens.
[180] Plato, Apol. So. c. 14; Xenoph. Memor. iv. 7.
That physical enquiries into the nature of things, and attempts to substitute scientific theories in place of the personal agency of the Gods, were repugnant to the religious feelings of the Greeks, has been already remarked.[181] Yet most of the other contemporary philosophers must have been open to this reproach, not less than Anaxagoras; and we learn that the Apolloniate Diogenes left Athens from the same cause. If others escaped the like prosecution which fell upon Anaxagoras, we may probably ascribe this fact to the state of political party at Athens, and to the intimacy of the latter with Perikles. The numerous political enemies of that great man might fairly hope to discredit him in the public mind — at the very least to vex and embarrass him — by procuring the trial and condemnation of Anaxagoras. Against other philosophers, even when propounding doctrines not less obnoxious respecting the celestial bodies, there was not the same collateral motive to stimulate the aggressive hostility of individuals.
[181] Plutarch, Nikias, 23.
Diogenes of Apollonia recognises one primordial element.
Contemporary with Anaxagoras — yet somewhat younger, as far as we can judge, upon doubtful evidence — lived the philosopher Diogenes, a native of Apollonia in Krete. Of his life we know nothing except that he taught during some time at Athens, which city he was forced to quit on the same ground as Anaxagoras. Accusations of impiety were either brought or threatened against him:[182] physical philosophy being offensive generally to the received religious sentiment, which was specially awakened and appealed to by the political opponents of Perikles.
[182] Diogen. Laert. ix. 52. The danger incurred by Diogenes the Apolloniate at Athens is well authenticated, on the evidence of Demetrius the Phalerean, who had good means of knowing. And the fact may probably be referred to some time after the year B.C. 440, when Athens was at the height of her power and of her attraction for foreign visitors — when the visits of philosophers to the city had been multiplied by the countenance of Perikles — and when the political rivals of that great man had set the fashion of assailing them in order to injure him. This seems to me one probable reason for determining the chronology of the Apolloniate Diogenes: another is, that his description of the veins in the human body is so minute and detailed as to betoken an advanced period of philosophy between B.C. 440-410. See the point discussed in Panzerbieter, Fragment. Diogen. Apoll. c. 12-18 (Leipsic, 1830).