11 Faustus has displayed his ingenuity, in the remarks to which I am now replying, by making for himself a long list of opposites— health and sickness, riches and poverty, white and black, cold and hot, sweet and bitter. We need not say much about black and white. Or, if there is a character for good or evil in colors, so that white must be ascribed to God and black to Hyle; if God threw a white color on the wings of birds, when Hyle, as the Manichæans say, created them, where had the crows gone to when the swans got whitened?
Nor need we discuss heat and cold, for both are good in moderation, and dangerous in excess. With regard to the rest, Faustus probably intended that good and evil, which he might as well have put first, should be understood as including the rest, so that health, riches, white, hot, sweet, should belong to good; and sickness, poverty, black, cold, bitter, to evil. The ignorance and folly of this is obvious. It might look like reviling if I were to take up separately white and black, hot and cold, sweet and bitter, health and sickness.
For if white and sweet are both good, and black and bitter evil, how is it that most grapes and all olives become black as they become sweet, and so get good by getting evil? And if heat and health are both good, and cold and sickness evil, why do bodies become sick when heated? Is it healthy to have fever? But I let these things pass, for they may have been put down hastily, or they may have been given as merely instances of opposition, and not as being good and bad, especially as it is nowhere stated that the fire among the race of darkness is cold, so that heat in this case must unquestionably be evil.
Source: Reply to Faustus the Manichaean (New Advent)