2. As man's mind is subordinate to God, so his body is subordinate to his soul, and his lower powers to his reason. It belongs therefore to divine providence, the plan of which, as proposed by God to man, is the divine law, to see that all things keep their order. Therefore that divine law must so direct man as that his lower powers shall be subject to his reason, and his body to his soul, and exterior things shall serve his necessity.
4. Every lawgiver must comprise in his legislation those enactments without which the law could not be observed. Now law being set over reason,* man could not follow the law unless all other things belonging to man were subjected to reason.
Hence it is said: Your reasonable service (Rom. xii, i); and, This is the will of God, your sanctification (i Thess. iv, 9).
Hereby is excluded the error of such as say that those acts alone are sinful, whereby our neighbour is either hurt or shocked.
3.120 : That the Worship of Latria is to be paid to God alone
3.122 : Of the reason for which Simple Fornication is a Sin by Divine Law, and of the Natural Institution of Marriage