Lactantius — Divine Institutes 6.2

They therefore sacrifice rich and fat victims to God as if to one hungry, pour out wines as if to one thirsty, kindle lights as if to one living in darkness. But if they could suspect or perceive in mind what those heavenly goods are, whose greatness we, still wrapped in an earthly body, cannot grasp by sense, they would already know themselves most foolish with these empty offices; or if they would gaze on the heavenly light which we call the sun, they would already feel how little God needs their lamps, who himself gave for human use so bright, so white a light. And yet when in so small a circle, which because of distance seems to have measure no more than a human head, there is so much brilliance that the edge of mortal eyes cannot look on it and if you aim a little, dullness and darkness follow the weakened eyes, what light finally, what brightness should we think is with God himself, with whom there is no night? Who moderated this very light so that it would not harm living things by too much brilliance or violent heat and gave it only so much of those things as either mortal bodies could bear or the ripening of crops required. Is he then to be thought master of his mind who offers to the author and giver of light the light of candles or wax as a gift? But that one demands from us another light and indeed not smoky, but, as the poet says, liquid and clear — namely of the mind — for which we are called φῶτες by the poets: which none can show except who has recognized God.

But their gods, because they are earthly, need lights lest they be in darkness: whose worshipers, because they taste nothing heavenly, also call back to earth the religions they serve: for in it there is need of light, because its reason and nature is dark. And so they attribute to the gods not heavenly sense but rather human and therefore believe necessary and pleasing to them what is to us, who when hungry need food or when thirsty drink or when cold clothing or when the sun has withdrawn light, that we may see. By no things therefore can it be so proved and understood that those gods, since they once lived, are dead as by the rite itself, which is wholly from earth. For what heavenly good can poured blood of cattle have in itself, with which they stain the altars? Unless perhaps they think the gods feed on that which humans refuse to touch. And whoever has provided them this stuffing, though he be a robber, adulterer, poisoner, parricide, will be blessed and happy; him they love, him they protect, to him they grant all he has wished. Deservedly therefore Persius mocks superstitions of this sort in his manner: 'By what wage,' he says, 'will you buy the gods' ears? With lung and greased guts?' He sensed clearly that flesh is not needed to placate heavenly majesty, but a holy mind and a just spirit and a breast, as he himself says, that is noble with natural honesty.

This is heavenly religion, not which consists of corrupt things, but which consists of virtues of the soul which rises from heaven; this is true worship, in which the worshiper's mind sets itself before God as an unblemished victim. But how that itself is to be attained, how it is to be rendered, this book's dispute will teach. For nothing can be so excellent and fitting for a human than to train humans to justice. In Cicero, Catulus in the Hortensius, preferring philosophy to all things, says he would rather have even one small booklet on duty than a long speech for the seditious man Cornelius. Which sentence is not certainly Catulus's, who perhaps did not say that, but is to be thought Cicero's, who wrote it, I believe that he might commend the books he was going to write on duties: in which themselves he testifies that there is nothing in all philosophy better and more fruitful than to give precepts of life. And if those do this who have not known the truth, how much more ought we to do it who, taught and illuminated by God, can give true precepts! And yet we will not teach so as to hand over as it were the first elements of virtue, which is endless, but as if we have undertaken to teach him who among them already seems perfect. For with their precepts remaining which they are accustomed to give rightly toward honesty, we will build on what is unknown to them to perfect and complete justice, which they do not hold. But those things that can be common with them I will pass by, lest I seem to borrow anything from those whose errors I have decided to convict and open.