1 Corinthians 8:4

We know that an idol is nothing in the world, and that there is none other than God but One. An idol is not what it is commonly supposed to be, not what it stands for, is not God. It has no Divine power; materially it is of wood, formally it is nothing. It is an image of a falsehood, or of a non-existent God. Consequently that which is offered to idols is as such nothing, has no Divinity or sanctity derived from the idol to which it was offered.

The word "idol" itself is derived from the Greek ειδος, which Tertullian says denotes appearance; and from it the diminutive, εί̉δωλον, was formed (de Idolol. ciii.). An "idol" among the earlier Greek writers denoted any empty and untrustworthy image, such as hollow phantasms, spectres, the shades of the dead, and the like. In the same way Holy Scripture and the Church writers have limited the term idol to an image of God which is evident from this verse. The LXX., too, throughout the Old Testament, apply the same term to the statues and gods of the heathen.

Hence Henry Stephen and John Scapula are deceived and deceive, when they lay down in their lexicons that the term idol is applied by ecclesiastical writers to any image representing some deity to which honour and worship are paid. It is not every statue or image of every god that is an idol, but only the image of a false god. Cf. Cyprian (de Exhort. Mart. c. i.), Tertullian (de Idolol.), Athanasius (contra Idola).

The Protestant fraud, therefore, must be guarded against which confounds idol with image, and concludes that all images are forbidden by those passages of Scripture which condemn idolatry. Cf. Ballarmine (de Imagin. lib. ii. c. 5), who shows unanswerably that an idol is the representation of what is false, an image of what is true. Ver. 5, 6. For though there be that are called gods,... to us there is but one God, &c. The pagans have gods many and lords many, as the sun, moon, and stars, or terrestrial gods, as Jupiter, Apollo, Hercules; but we have only one God, for whose glory and honour we were created.

Notice also against the Arians that, when S. Paul says One God, he is only excluding false gods, not the Son and the Holy Spirit. When he says One Lord Jesus Christ, he is only excluding false lords, not the Father and the Holy Spirit.