503. The perceptive faculty of the Most Ancient Church consisted not only in the perception of what is good and true, but also in the happiness and delight arising from well-doing; without such happiness and delight in doing what is good the perceptive faculty has no life, but by virtue of such happiness and delight it receives life. The life of love, and of the derivative faith, such as the Most Ancient Church enjoyed, is life while in the performance of use, that is, in the good and truth of use: from use, by use, and according to use, is life given by the Lord; there can be no life in what is useless, for whatever is useless is cast away. In this respect the most ancient people were likenesses of the Lord, and therefore in perceptive powers they became images of Him. The perceptive power consists in knowing what is good and true, consequently what is of faith: he who is in love is not delighted in knowing, but in doing what is good and true, that is, in being useful.