The Second Commandment famously declares that God is not to be worshiped by images. 1 In Book 4 of City of God, Augustine remarks that Varro came very close to the truth of things (under compulison from “the secret will of God), and knew of Jewish practice in this area; but traditional Roman practice was too far gone by this point, giving rise to “the prejudices of custom,” for aniconic practice to be institutionalized–though if Varro were founding a new state, that is precisely how he would arrange things. Still, even though such worship could not be instituted at that time or by that man, the aniconic principle corresponds to the way things are in fact, as Augustine plainly declares. The freedom from such worship Augustine attributes to the sacrifice of Christ and the impartation of the Spirit.
[Varro] says, also, that the ancient Romans, for more than a hundred and seventy years, worshipped the gods without an image.187 “And if this custom,” he says, “could have remained till now, the gods would have been more purely worshipped.” In favor of this opinion, he cites as a witness among others the Jewish nation; nor does he hesitate to conclude that passage by saying of those who first consecrated images for the people, that they have both taken away religious fear from their fellow-citizens, and increased error, wisely thinking that the gods easily fall into contempt when exhibited under the stolidity of images. But as he does not say they have transmitted error, but that they have increased it, he therefore wishes it to be understood that there was error already when there were no images. Wherefore, when he says they alone have perceived what God is who have believed Him to be the governing soul of the world, and thinks that the rites of religion would have been more purely observed without images, who fails to see how near he has come to the truth? For if he had been able to do anything against so inveterate an error, he would certainly have given it as his opinion both that the one God should be worshipped, and that He should be worshipped 82without an image; and having so nearly discovered the truth, perhaps he might easily have been put in mind of the mutability of the soul, and might thus have perceived that the true God is that immutable nature which made the soul itself. Since these things are so, whatever ridicule such men have poured in their writings against the plurality of the gods, they have done so rather as compelled by the secret will of God to confess them, than as trying to persuade others. If, therefore, any testimonies are adduced by us from these writings, they are adduced for the confutation of those who are unwilling to consider from how great and malignant a power of the demons the singular sacrifice of the shedding of the most holy blood, and the gift of the imparted Spirit, can set us free. (City of God 4.31)
This sentiment of his echoes what he said in the previous chapter of the opinions of Lucilius Balbus in Cicero, On the Nature of the Gods 2:
When, therefore, these things are found fault with as superstitious, he implicates in that fault the ancients who instituted and worshipped such images. Nay, he implicates himself, who, with whatever eloquence he may strive to extricate himself and be free, was yet under the necessity of venerating these images; nor dared he so much as whisper in a discourse to the people what in this disputation he plainly sounds forth. Let us Christians, therefore, give thanks to the Lord our God—not to heaven and earth, as that author argues, but to Him who has made heaven and earth; because these superstitions, which that Balbus, like a babbler,185 scarcely reprehends, He, by the most deep lowliness of Christ, by the preaching of the apostles, by the faith of the martyrs dying for the truth and living with the truth, has overthrown, not only in the hearts of the religious, but even in the temples of the superstitious, by their own free service. (City of God 4.30)
Incidentally, one place in which we find the same belief as that voiced by Varro about early Roman worship without images is, as is noted in the translation above, Plutarch’s Life of Numa. For reference’s sake, here is what he says:
[Numa’s] legislation about images was also connected with the Pythagorean doctrine, which says that first principles cannot be touched or seen, but are invisible spiritual essences; for Numa forbade the Romans to worship any likenesses of men or of beasts. Among them there was no image of a god, either carved or moulded, in the early times. For a hundred and seventy years they built temples, and placed shrines in them, but made no image of any living thing, considering that it was wrong to make the worse like the better, and that God cannot be comprehended otherwise than by thought. (Numa 8)