1/14) St. Paul says that “Sin came into the world through one man.” (Romans 5:12). He doesn’t only mean that Adam gave us an example of sin, rather that is attributed to the devil; “by the envy of the devil, death came into the world.” (Wisdom 2:24)

2/14) Aristotle says, we don’t blame people for being born blind; we pity them. So Aquinas writes that we have to approach the question of the inheritance of sin in light of such things.

3/14) Rather, all men born from Adam can be thought of as one man sharing one nature derived from him. In such the same way that in political matters, all the members of a social order are thought of as limbs or members of one body.

4/14) The actions of bodily members, like the hand, are deliberated, not with any will in the hand, but with the will of the intellect which first set the hand in motion.

5/14) We would not reckon murder committed with the hand to be the hand’s sin if we could think of the hand in itself out of the context of the body.

6/14) We talk of it in that way only when we think of the hand as part of a whole man moved to sin by the source of such movements in men.

7/14) The ontologically absolute character of St. Thomas’s political theology is palpable - the body/social order, is disciplined by its intentional guiding principle; intellect/sovereign.

8/14) Aquinas continues in his discussion of original sin’s inheritance that, in the same way, the disorder inherited from Adam by any particular man is not deliberative with that man’s will --

9/14) -- but only deliberate with Adam’s will which activates all those born from him by movements of reproduction, just as the will of a man activates all his limbs.

10/14) This is why sin deriving from our first parent is called original -- meaning “by origin” or “inheritance” -- where as the sins deriving from a man’s will to members of his body are called “actional” -- sins of action.

11/14) Every part is directed to the whole, as imperfect to perfect, wherefore every part exists naturally for the sake of the whole.

12/14) For this reason we see that if the health of the whole human body demands the excision of a member, because it became putrid or infectious to the other members, it would be both praiseworthy and healthful to have it cut away.

13/14) Now every individual person is related to the entire society as a part to the whole.

14 /14) Therefore if a man be dangerous and infectious to the community, on account of some sin, it is praiseworthy and healthful that he be killed in order to safeguard the common good, since "a little leaven corrupteth the whole lump” (1 Cor. 5:6).