Lactantius — Divine Institutes 2.8

It is therefore right, especially in a matter on which the whole plan of life turns, that every one should place confidence in himself, and use his own judgment and individual capacity for the investigation and weighing of the truth , rather than through confidence in others to be deceived by their errors , as though he himself were without understanding. God has given wisdom to all alike, that they might be able both to investigate things which they have not heard, and to weigh things which they have heard. Nor, because they preceded us in time, did they also outstrip us in wisdom; for if this is given equally to all, we cannot be anticipated in it by those who precede us. It is incapable of diminution, as the light and brilliancy of the sun; because, as the sun is the light of the eyes, so is wisdom the light of man's heart.

Wherefore, since wisdom — that is, the inquiry after truth — is natural to all, they deprive themselves of wisdom, who without any judgment approve of the discoveries of their ancestors, and like sheep are led by others. But this escapes their notice, that the name of ancestors being introduced, they think it impossible that they themselves should have more knowledge because they are called descendants, or that the others should be unwise because they are called ancestors. What, therefore, prevents us from taking a precedent from them, that as they handed down to posterity their false inventions, so we who have discovered the truth may hand down better things to our posterity?

There remains therefore a great subject of inquiry, the discussion of which does not come from talent, but from knowledge : and this must be explained at greater length, that nothing at all may be left in doubt . For perhaps some one may have recourse to those things which are handed down by many and undoubted authorities; that those very persons , whom we have shown to be no gods, have often displayed their majesty both by prodigies, and dreams, and auguries, and oracles.

And, indeed, many wonderful things may be enumerated, and especially this, that Accius Navius, a consummate augur, when he was warning Tarquinius Priscus to undertake the commencement of nothing new without the previous sanction of auguries, and the king, detracting from the credit due to his art, told him to consult the birds, and then to announce to him whether it was possible for that which he himself had conceived in his mind to be accomplished, and Navius affirmed that it was possible; then take this whetstone, he said, and divide it with a razor. But the other without any hesitation took and cut it. In the next place is the fact of Castor and Pollux having been seen in the Latin war at the lake of Juturna washing off the sweat of their horses, when their temple which adjoins the fountain had been open of its own accord.