1. Man has received the knowledge of good and evil. It is good to obey God, and to believe in Him, and to keep His commandment, and this is the life of man; as not to obey God is evil, and this is his death. Since God, therefore, gave [to man] such mental power (magnanimitatem), man knew both the good of obedience and the evil of disobedience, that the eye of the mind, receiving experience of both, may with judgment make choice of the better things; and that he may never become indolent or neglectful of God's command; and learning by experience that it is an evil thing which deprives him of life, that is, disobedience to God, may never attempt it at all, but that, knowing that what preserves his life, namely, obedience to God, is good, he may diligently keep it with all earnestness. Wherefore he has also had a twofold experience, possessing knowledge of both kinds, that with discipline he may make choice of the better things. But how, if he had no knowledge of the contrary, could he have had instruction in that which is good? For there is thus a surer and an undoubted comprehension of matters submitted to us than the mere surmise arising from an opinion regarding them. For just as the tongue receives experience of sweet and bitter by means of tasting, and the eye discriminates between black and white by means of vision, and the ear recognises the distinctions of sounds by hearing; so also does the mind, receiving through the experience of both the knowledge of what is good, become more tenacious of its preservation, by acting in obedience to God: in the first place, casting away, by means of repentance, disobedience, as being something disagreeable and nauseous; and afterwards coming to understand what it really is, that it is contrary to goodness and sweetness, so that the mind may never even attempt to taste disobedience to God. But if any one do shun the knowledge of both these kinds of things, and the twofold perception of knowledge, he unawares divests himself of the character of a human being.