[145] For it is the greatest folly imaginable to estimate the antiquity of the human race from the state of art; for if any one were to follow the absurdity of such a system of reasoning as this, he will prove the world to be very young indeed, and to have been made scarcely a thousand years, since all those men whom we have heard of traditionally as the discoverers in different branches of science do not go back to a greater number of years than that which I have mentioned.