Chapter 31 — Part III: The Decalogue — The Eighth Commandment
Section 8. False Testimony In Favour Of A Neighbour Is Also Forbidden — But if we are forbidden to injure our neighbour by false testimony, let it not be inferred that the contrary is lawful, and that we may help by perjury those who are bound to us by ties of kinship or religion. It is never allowed to have recourse to lies or deception, much less to perjury. Hence St. Augustine in his book to Crescentius On Lying teaches from the words of the Apostle that a lie, although uttered in false praise of anyone, is to be numbered among false testimonies. Treating of that passage, Yea, and we are found false witnesses of God, because we have given testimony against God, that he hath raised up Christ whom he hath not raised, if the dead rise not again, he says: The Apostle calls it false testimony to utter a lie with regard to Christ, even though it should seem to redound to His praise.