§ 1. On Idolatry

556. DEFINITION. Idolatry is superstition by which honor is attributed to a creature as to God.

But this is done by any sign of honor by which someone intends to submit himself to a creature as to God, for example by genuflection, incense-burning, uncovering of the head before an idol. Thus the idolatry of the Gentiles was the worship of demons, as is said (Ps. 95:5): All the gods of the Gentiles are demons.

DIVISION. Idolatry, by reason of affection, is twofold: one MATERIAL or simulated, as when someone, without internal affection, from fear of death, exhibits worship to an idol; the other FORMAL and proper, and this is either perfect, as when someone adores an idol which from infidelity he thinks to be God; or imperfect, when someone, either from hatred of God, or from affection for obtaining something from a demon or another creature, offers worship to it as if to God.

Hence you will deduce: 1. Idolatry, even material and feigned, is a grave and mortal sin; because it is a pernicious lie, and against religion, and often also against the precept of externally professing the faith (cf. n. 429). 2. Imperfect idolatry, on account of malice of the will, is a graver sin than perfect idolatry (III, 12, 13).