Chapter XII.—Waste of Mental Energy in the Systems of the Astrologers. Who will not feel astonishment at the exertion of so much deep thought with so much toil? This Ptolemy, however—a careful investigator of these matters—does not seem to me to be useless; but only this grieves (one), that being recently born, he could not be of service to the sons of the giants, who, being ignorant of these measures, and supposing that the heights of heaven were near, endeavoured in vain to construct a tower.  And so, if at that time he were present to explain to them these measures, they would not have made the daring attempt ineffectually. But if any one profess not to have confidence in this (astronomer’s calculations), let him by measuring be persuaded (of their accuracy); for in reference to those incredulous on the point, one cannot have a more manifest proof than this. O, pride of vain-toiling soul, and incredible belief, that Ptolemy should be considered pre-eminently wise among those who have cultivated similar wisdom!