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. It does so in several ways. The creature is often represented by an image, an idol. "Some, by nefarious arts, made certain images which, through the power of the devil, produced certain effects whence they thought that these images contained something divine and, consequently, that divine, worship was due to them." Such was the opinion of Hermes Trismegistus. Others gave Divine honours not to the images but to the creatures which they represented. Both are hinted at by the Apostle (Rom., I, 23-25), who says of the first: "They changed the glory of the incorruptible God into the likeness of the image of a corruptible man, and of birds, and of four-footed beasts and of creeping things"; and of the second: "They worshipped and served the creature rather than the Creator". These worshippers of creatures were of three kinds. Some held that certain men were gods, and these they honoured through their statues, e. g., Jupiter and Mercury. Others opined that the whole world was one God, God being conceived of as the rational soul of the corporeal world. Hence they worshipped the world and all its parts, the air, the water, and all the rest; their idols, according to Varro, as reported by St. Augustine (De Civ. Dei, VIII, xxi, xxii), were the expression of that belief. Others again, followers of Plato, admitted one supreme God, the cause of all things; under Him they placed certain spiritual substances of His creation and participating in His Divinity; these substances they called gods; and below these they put the souls of the heavenly bodies and, below these again the demons who, they thought, were a sort of aerial living beings (animalia). Lowest of all they placed the human souls, which, according to merit or demerit, were to share the society either of the gods or of the demons. To all they attributed Divine worship, as St. Augustine says (De Civ. Dei, VIII, 14).
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. find., 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" (Rom., ii, 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.
Idolatry in its grosser forms is so far removed from the Christianized mind that it is no easy matter to account for its origin. Its persistence after gaining a first footing, and its branching out in countless varieties, are sufficiently explained by the moral necessity imposed on the younger generation to walk in the path of their elders with only insignificant deviations to the right or to the left. Thus Christian generations follow upon Christian generations; if sects arise they are Christian sects. The question as to the first origin of idolatry is thus answered by St. Thomas: "The cause of idolatry is twofold: dispositive on the part of man; consummative on the part of the demons. Men were led to idolatry first by disordered affections, inasmuch as they bestowed divine honours upon someone whom they loved or venerated beyond measure. This cause is indicated in Wisdom, xiv, 15: 'For a father being afflicted by bitter grief, made to himself the image of his son who was quickly taken away; and him who then had died as a man, he began now to worship as a god . . . ', and xiv, 21: 'Men serving either their affection or their king, gave the incommunicable name to stones and wood'. Second: By their natural love for artistic representations: uncultured men, seeing statues cunningly reproducing the figure of man, worshipped them as gods. Hence we read in Wisdom, xiii, 11 sq., 'An artist, a carpenter has cut down a tree proper for his use in the wood . . . . . . and by the skill of his art fashioneth it and maketh it like the image of a man . . . . . and then maketh prayers to it, inquiring concerning his substance and his children or his marriage'. Third: By their ignorance of the true God: man, not considering the excellence of God, attributed divine worship to certain creatures excelling in beauty or virtue: Wisdom, xiii, 1-2:' . . . . . neither by attending to the works have [men] acknowledged who was the workman, but have imagined either the fire, or the wind, or the swift air, or the circle of the stars, or the great water, or the sun and moon, to be the gods that rule the world'. - The consummative cause of idolatry was the influence of the demons who offered themselves to the worship of erring men, giving answers from idols or doing things which to men seemed marvelous, whence the Psalmist says (Ps. xcv, 5): 'All the gods of the gentiles are devils'" (II-II, Q. xciv, a. 4).
The causes which the writer of Wisdom, probably an Alexandrian Jew living in the second century B. C., assigns to the idolatry prevalent in his time and environment, are sufficient to account for the origin of all idolatry. Man's love for sense images is not a vagary but a necessity of his mind. Nothing is in the intellect that has not previously passed through the senses. All thought that transcends the sphere of direct sense knowledge is clothed in material garments, be they only a word or a mathematical symbol. Likewise, the knowledge of things impervious to our senses, that comes to us by revelation, is communicated and received through the senses external or internal, and is further elaborated by comparison with notions evolved from sense perceptions; all our knowledge of the supernatural proceeds by analogy with the natural. Thus, throughout the Old Testament God reveals Himself in the likeness of man, and in the New, the Son of God, assuming human nature, speaks to us in parables and similitudes. Now, the human mind, when sufficiently ripe to receive the notion of God, is already stocked with natural imagery in which it clothes the new idea. That the limited mind of man cannot adequately represent, picture, or conceive the infinite perfection o God, is self-evident. If left to his own resources, man will slowly and imperfectly develop the obscure notion of a superior or supreme power on which his well-being depends and whom he can conciliate or offend. In this process intervenes the second cause of idolatry: ignorance. The Supreme Power is apprehended in the works and workings of nature; in sun and stars, in fertile fields, in animals, in fancied invisible influences, in powerful men. And there, among the secondary causes, the "groping after God" may end in the worship of sticks and stones. St. Paul told the Athenians that God had "winked at the times of this ignorance" during which they erected altars "To the unknown God", which implies that He had compassion on their ignorance and sent them the light of truth to reward their good intention (Acts, xvii, 22-31). As soon as the benighted heathen has located his unknown god, love and fear, which are but the manifestations of the instinct of self-preservation, shape the cultus of the idol into sacrifices or other congenial religious practices. Ignorance of the First Cause, the need of images for fixing higher conceptions, the instinct of self-preservation - these are the psychological causes of idolatry.
IDOLATRY IN ISRAEL
The worship of one God is inculcated from the first to the last page of the Bible. How long man, on the strength of the revelation transmitted by Adam and subsequently by Noe, adored God in spirit and truth is an insoluble problem. Monotheism, however, appears to have been the starting-point of all religious systems known to us through trustworthy documents. The Animism, Totemism, Fetishism of the lower races; the nature-worship, ancestor-worship, and hero-worship of civilized nations are hybrid forms of religion, evolved on the psychological lines indicated above; all are incarnations in the uncultured or cultured mind, and manifestations of one fundamental notion, namely, that there is above man a power on whom man is dependent for good and evil. Polytheism is born of the confusion of second causes with the First Cause; it grows in inverse ratio of higher mental faculties; it dies out under the clear light of reason or revelation. The first undoubted mention of idolatry in the Bible is in Genesis, xxxi, 19: "Rachel stole away her father's idols [teraphim]", and when Laban overtook Jacob in his flight and made search for "his gods", Rachel "in haste hid the idols under the camel's furniture, and sat upon them" (xxxi, 34). Yet Laban also worshipped the same God as Jacob, whose blessing he acknowledges (xxx, 27), and on whom he calls to judge between him and Jacob (xxxi, 53). A similar practice of blending reverence to the true God with the idolatrous worship of surrounding nations runs though the whole history of Israel. When Moses delayed to come down from the holy mount, the people, "gathering together against Aaron, said: Arise, make us gods, that may go before us". And Aaron made a molten calf, "and they said: These are thy gods, O Israel, that have brought thee out of the land of Egypt. And . . . they offered holocausts, and peace victims, and the people sat down to eat, and drink, and they rose up to play" (Exodus, xxxii, 1 sqq.). In Settim "the people committed fornication with the daughters of Moab, . . . and adored their gods. And Israel was initiated to Beelphegor" (Numbers xxv 1-3). Again, after the death of Josue, "the children 6f Israel . . . served Baalim . . . and they followed strange gods, and the gods of the people that dwelt round about them" (Judges, ii, 11 sq.) . Whenever the children of Israel did evil in the eyes of Jehovah, swift retribution overtook them; they were given into the hands of their enemies. Yet idolatry remained the national sin down to the times of t e Machabees. This striking fact has for its causes, first, the natural endeavour of man to come in contact with the object of his worship; he wants gods that go before him, visible, tangible, easily accessible; in the case of the Israelites the strict prohibition of worshipping images added to idolatry the allurement of the forbidden fruit; secondly, the allurement of the pleasures of the flesh offered to the worshippers of the strange divinities; thirdly, mixed marriages, occasionally on a large scale; fourthly, the intercourse in peace and war and exile with powerful neighbours who attributed their prosperity to other gods than Jehovah. The less enlightened Israelites probably conceived of the God of Abraham, Isaac, and Jacob as "their God", Who laid no claim to universal rule. If so, they may frequently have become idolaters for the sake of temporal advantage.
But why did God permit such deviations from the truth? If in His judgment idolatry, as practised by the Jews, is the unmitigated evil which it appears to our judgment, no satisfactory answer can be given to this question, it is the eternal problem of sin and evil. The best that can be said is that the constantly recurring cycle of sin, punishment, repentance, forgiveness, were for God the occasion of a magnificent display of justice, mercy, and longanimity; to the Chosen People a constant reminder of their need of a Redeemer; to the members of the Kingdom of Christ a type of God's dealings with sinners. It may also be pleaded that idolatry in Israel had more the character of ignorant superstition than of contempt of Jehovah. Like the superstitious or quasi-superstitious practices and devotions to which even Christian populations are prone, much of the idolatrous cult in Israel was an excess of piety, rather than an act of impiety, towards the Supreme Power distinctly felt but dimly understood. The well-meant but ill-directed worship never became the religion of Israel; it was never more than a temporary invasion of extraneous religious practices, often deeply overlaying the national religion, but never completely supplanting it. As a last consideration, the punishment of idolatry in Israel was always national and temporal. The prophets held out no eternal bliss or eternal torments as incentives to faithful service of God. And the Prophet of prophets, Christ the Judge, may well repeat from the seat of judgment the words He spoke on the Cross: "Father, forgive them, for they know not what they do".
IDOLATRY AMONG THE HEATHEN
The causes at work in the genesis of idolatry have produced effects as varied and manifold as the human family itself. The original idea of God has taken in the mind of man all the distorted and fanciful forms which a liquid is liable to assume in a collapsible vessel, or clay in the potter's hands. As, in the course of ages, the power of healing has been attributed to almost every substance and combination of substances, so has the Divine power been traced in all things, and all things have been worshipped accordingly. As an illustration, the worship of animals may be briefly considered. From the beginning and throughout his history, man is associated with the lower animals. Adam is surrounded by them in Eden, and Eve speaks familiarly to the serpent. Sacrificed animals link man to God, from the sacrifice of Abel to the taurobolium of the latest superstition of pagan Rome. The scapegoat carries with it the sins of the people, the paschal lamb redeems them. The Lamb that taketh away the sins of the world, the dove which represents the Holy Ghost, the animal emblems of the Evangelists, the dragon of St. Michael and of St. George of England, not to mention others, are familiar to Christians.
The heathen mind has moved in similar grooves. In oldest Egypt we find the bull associated with the godhead and receiving divine homage - whether as a special representative, a manifestation, a symbol, or a receptacle of the divinity, it is impossible to decide. From the seventh century B. C. onwards every god is figured with the head of some animal sacred to him; Thot has the head of an ibis, Amon a ram's, Horus a hawk's, Anubis a jackal's, etc. Were the Egyptians and other zoolaters guided by the same symbolism that leads us to call on "the Lamb of God" for forgiveness of our sins? If so animal-worship runs through the following stages: Man's close association with animal life fills his mental storehouse with composite notions - e. g., the faithful dog, the sly fox, the cunning serpent, the patient ass - in which the animal embodies a human attribute. Next, the adjective is dropped, and the animal name is used as a predicate of persons, as a personal, family, tribal, or divine name. At this point the process branches off according to the religious temper of the people. Where Monotheism rules, the animal, alive or figured, is but an emblem or a symbol; among untutored savages, like the Red Indians, it is the bearer of the tribe's tutelary spirit and the object of various degrees of worship; in decaying religions - e. g., Egyptian later polytheism - it is identified with the god whose characteristic it represents, and shares with him in divine honours. The light of Revelation has cleared away the aberrations of this natural process wherever it has penetrated, but traces of it remain embedded in many, perhaps in all, languages. Thus Wodan's sacred wolf still enters into 357 personal names borne by Germans. (See also IMAGES; RELIGION; WORSHIP.)
For dogmatic and moral side, see works quoted in text. The history of idolatry is now studied as comparative religion, hut as yet there is no standard Catholic work on the subject. For monographs, see BABYLONIA; CHINA; EGYPT; GREECE; also the series of the London Catholic Truth Society, History of Religion (32 lectures in 4 vols., London, 1908 - ); and two similar series, each called Science et Religion (Paris).