(Greek eidololatria.)
Idolatry etymologically denotes Divine worship given to an image, but its signification has been extended to all Divine worship given to anyone or anything but the true God. St. Thomas (Summa Theol., II-II, q. xciv) treats of it as a species of the genus superstition, which is a vice opposed to the virtue of religion and consists in giving Divine honour (cultus) to things that are not God, or to God Himself in a wrong way. The specific note of idolatry is its direct opposition to the primary object of Divine worship; it bestows on a creature the reverence due to God alone.
An essential difference exists between idolatry and the veneration of images practised in the Catholic Church, viz., that while the idolater credits the image he reverences with Divinity or Divine powers, the Catholic knows "that in images there is no divinity or virtue on account of which they are to be worshipped, that no petitions can be addressed to them, and that no trust is to be placed in them. . . that the honour which is given to them is referred to the objects (prototypa) which they represent, so that through the images which we kiss, and before which we uncover our heads and kneel, we adore Christ and venerate the Saints whose likenesses they are" (Conc. Trid., Sess. XXV, "de invocatione Sanctorum").
Considered in itself, idolatry is the greatest of mortal sins. For it is, by definition, an inroad on God's sovereignty over the world, an attempt on His Divine majesty, a rebellious setting up of a creature on the throne that belongs to Him alone. Even the simulation of idolatry, in order to escape death during persecution, is a mortal sin, because of the pernicious falsehood it involves and the scandal it causes. Of Seneca who, against his better knowledge, took part in idolatrous worship, St. Augustine says: "He was the more to be condemned for doing mendaciously what people believed him to do sincerely".
The guilt of idolatry, however, is not to be estimated by its abstract nature alone; the concrete form it assumes in the conscience of the sinner is the all-important element. No sin is mortal — i.e. debars man from attaining the end for which he was created — that is not committed with clear knowledge and free determination. But how many, or how few, of the countless millions of idolaters are, or have been, able to distinguish between the one Creator of all things and His creatures? and, having made the distinction, how many have been perverse enough to worship the creature in preference to the Creator? — It is reasonable, Christian, and charitable to suppose that the "false gods" of the heathen were, in their conscience, the only true God they knew, and that their worship being right in its intention, went up to the one true God with that of Jews and Christians to whom He had revealed Himself. "In the day when God shall judge the secrets of men by Jesus Christ . . . . . the gentiles who have not the law, shall be judged by their conscience" (Romans 2:14-16). God, who wishes all men to be saved, and Christ, who died for all who sinned in Adam, would be frustrated in their merciful designs if the prince of this world were to carry off all idolaters.
