12. Who will not wonder at so much activity of mind produced by so great labour? It seems that this Ptolemy[67] who busies himself with these matters is not without his use to me. This only grieves me that as one but lately born he was not serviceable to the sons of the giants,[68] who, being ignorant of these measurements, thought they were near high heaven and began to make a useless tower. Had he been at hand to explain these measurements to them they would not have ventured on the foolishness. But if any one thinks he can disbelieve this let him take the measurements and be convinced; for one cannot have for the unbelieving a more manifold proof than this. O puffing-up of vainly-toiling soul and unbelieving belief, when Ptolemy is considered wise in everything by those trained in the like wisdom![69] 13. Certain men in part intent on these things as judging [Sidenote: p. 76.] them mighty and worthy of argument have constructed measureless[70] and boundless heresies. Among whom is one Colarbasus,[71] who undertakes to set forth religion by measures and numbers. And there are others whom we shall likewise point out when we begin to speak of those who give heed to Pythagorean reckoning as if it were powerful and neglect the true philosophy for numbers and elements, thus making vain divinations. Collecting whose words, certain men have led astray the uneducated, pretending to know the future and when they chance to divine one thing aright are not ashamed of their many failures, but make a boast of their one success. Nor shall I pass over their unwise wisdom, but when I have set forth their attempts to establish a religion from these sources, I shall refute them as being disciples of a school inconsistent and full of trickery. 2. _Of Mathematicians._[72]