Thomas Aquinas

“ Accordingly such persons are inclined of themselves to those objects, not as to something foreign but as to something of their own. For this reason, too, the Old Law is described as "restraining the hand, not the will" [*Peter Lombard, Sent. iii, D, 40] ; since when a man refrains from some sins through fear of being punished, his will does not shrink simply from sin, as does the will of a man who refrains from sin through love of righteousness: and hence the New Law, which is the Law of love, is said to restrain the will. ”

“ For the Law fixed a limit to revenge, by forbidding men to seek vengeance unreasonably: whereas Our Lord deprived them of vengeance more completely by commanding them to abstain from it altogether. With regard to the hatred of one's enemies, He dispelled the false interpretation of the Pharisees, by admonishing us to hate, not the person, but his sin. ”

“ And in this respect, the New Law fulfils the Old by justifying men through the power of Christ's Passion. This is what the Apostle says (Rom. 8:3,4) : "What the Law could not do . . . God sending His own Son in the likeness of sinful flesh . . . hath condemned sin in the flesh, that the justification of the Law might be fulfilled in us." And in this respect, the New Law gives what the Old Law promised, according to 2 Cor. ”

“ Thus it is clear that movements differ in species through being directed to different terms: while according as one part of a movement is nearer to the term than another part, the difference of perfect and imperfect movement is assessed. ”

“ On the contrary, the Law was unwilling that a man should put away his wife, since it prescribed a delay, so that excessive eagerness for divorce might cease through being weakened during the writing of the bill. Hence Our Lord, in order to impress the fact that a wife ought not easily to be put away, allowed no exception save in the case of fornication." The same applies to the prohibition about swearing, as stated above. The same is also clear with respect to the prohibition of retaliation. ”

“ Secondly, two laws may be distinguished from one another, through one of them being more closely connected with the end, and the other more remotely: thus in one and the same state there is one law enjoined on men of mature age, who can forthwith accomplish that which pertains to the common good ”

“ For those who as yet are not endowed with virtuous habits, are directed to the performance of virtuous acts by reason of some outward cause: for instance, by the threat of punishment, or the promise of some extrinsic rewards, such as honor, riches, or the like. ”

“ Now this is very difficult to a man without virtue: thus even the Philosopher states (Ethic. v, 9) that it is easy to do what a righteous man does; but that to do it in the same way, viz. with pleasure and promptitude, is difficult to a man who is not righteous. ”