Q606
What is forbidden by the words, ‘Thou shalt not covet thy neighbor’s wife?’
This commandment extends the scope of the Seventh Commandment (the sixth in the Augustinian numbering): it calls us to reject all lustful thoughts, sensual fantasies, and desires that are not directed toward our spouse, that is, all inward sexual immorality. Certainly, this commandment is to be received in its broad sense: the one who is married may direct his or her desire only toward his or her lawful spouse; and the unmarried are called to the same purity of heart, each according to his state.
