For that sage, in declaring the sun to be fire, ignored the facts than men can look at fire without inconvenience, but cannot gaze steadily at the sun; that their skin is blackened by the sun’s rays, but not by fire. Further, he ignored the fact that sunlight is essential to the health of all vegetation, whereas if anything is heated by fire it withers. Again, when he pronounced the sun to be a red-hot stone, he ignored the fact that a stone in fire neither glows nor can resist it long, whereas the sun shines with unequalled brilliance for ever.

He also recommended the study of arithmetic. But in this case as in the others he recommended avoidance of vain application; and invariably, whether theories or ascertained facts formed the subject of his conversation, he limited it to what was useful.