Lactantius, Divine Institutes 6.6

First I argued that knowing what is good is not the same as virtue; then I defined virtue and showed where it resides. It follows that I must now briefly demonstrate that the philosophers were ignorant of what good and evil truly are, since this was nearly proven in the third book when I discussed the highest good. Those who did not know the highest good necessarily erred concerning all other goods and evils, which are not the highest; no one can rightly judge these things who does not grasp the very source from which they flow. The source of all good is God; the source of evil is the one who is the constant enemy of the divine name, whom I have often mentioned. From these two principles all good and evil originate. Whatever comes from God has this purpose: it brings immortality, which is the highest good. Whatever comes from that other source has this function: it kills and destroys those who have been drawn away from heavenly things and plunged into earthly things, consigning them to eternal punishment, which is the highest evil. Is it doubtful, then, that all those philosophers were ignorant of good and evil, since they knew neither God nor God's adversary? Consequently they limited the end of all goods to the body and to this brief life, which must inevitably dissolve and die; they advanced no further. All their precepts and all the goods they propose cling to the earth and lie in the dust, because they perish together with the body, which is earth. These things do not pertain to the true life of man, but to the pursuit or increase of wealth, honors, glory, and power — all of which are mortal, just like the person who toiled to obtain them. Hence the saying: virtue consists in knowing the end and measure of a thing. For they teach the means and arts by which family wealth is to be sought, because they see it is usually sought badly. But such virtue is not set before the wise; virtue is not the quest for wealth, whose discovery and possession are not in our power. Thus both the seeking and the obtaining of wealth are easier for the wicked than for the good. Therefore virtue cannot reside in those things which are sought, since it is in despising them that virtue's power and reason appear; nor will virtue turn to those very things which a great and lofty soul strives to trample and spurn. Nor is it right that a soul intent on heavenly goods should be diverted from its immortal possessions to acquire these fragile things. Rather, the reason of virtue consists in securing those goods which neither any human being nor death itself can take from us.