And to speak generally, in regard of things celestial he set his face against attempts to excogitate the machinery by which the divine power formed its several operations. (17) Not only were these matters beyond man's faculties to discover, as he believed, but the attempt to search out what the gods had not chosen to reveal could hardly (he supposed) be well pleasing in their sight. Indeed, the man who tortured his brains about such subjects stood a fair chance of losing his wits entirely, just as Anaxagoras, (18) the headiest speculator of them all, in his attempt to explain the divine mechanism, had somewhat lost his head. Anaxagoras took on himself to assert that sun and fire are identical, (19) ignoring the fact that human beings can easily look at fire, but to gaze steadily into the face of the sun is given to no man; or that under the influence of his rays the colour of the skin changes, but under the rays of fire not. (20) He forgot that no plant or vegetation springs from earth's bosom with healthy growth without the help of sunlight, whilst the influence of fire is to parch up everything, and to destroy life; and when he came to speak of the sun as being a "red-hot stone" he ignored another fact, that a stone in fire neither lights up nor lasts, whereas the sun-god abides for ever with intensist brilliancy undimmed. (17) Or, "he tried to divert one from becoming overly-wise in heavenly matters and the 'mecanique celeste' of the Godhead in His several operations." See above, I. i. 11. See Grote, "Plato," i. 438. (18) Of Clazomenae. Cf. Plat. "Apol." 14; Diog. Laert. II. vi; Cic. "Tusc." V. iv. 10; Cobet, "Prosop. Xen." s.n.; Grote, "H. G." i. 501. (19) Or, "that the sun was simply a fire, forgetting so simple a fact as that." (20) Or, "the complexion darkens, whereas fire has no such effect." Socrates inculcated the study of reasoning processes, (21) but in these, equally with the rest, he bade the student beware of vain and idle over-occupation. Up to the limit set by utility, he was ready to join in any investigation, and to follow out an argument with those who were with him; but there he stopped. He particularly urged those who were with him to pay the utmost attention to health. They would learn all it was possible to learn from adepts, and not only so, but each one individually should take pains to discover, by a lifelong observation of his own case, what particular regimen, what meat or drink, or what kind of work, best suited him; these he should turn to account with a view to leading the healthiest possible life. It would be no easy matter for any one who would follow this advice, and study his own idiosyncrasy, to find a doctor to improve either on the diagnosis or the treatment requisite. (22)