Chapter 196 — Whether the privation of original justice has the nature of sin in posterity

But there remains a more pressing question: whether the lack of original justice can have the character of sin in those who descend from the first parent. The notion of sin seems to require, as we said above, that a culpable evil be in the power of him to whom it is imputed as fault. No one is blamed for that which is beyond his power to do or not to do. But it is not in the power of a person who is born to be born with or without original justice. Hence it seems that such a lack cannot have the character of sin.

But this question is easily solved if we distinguish between person and nature. As there are many members in one person, so there are many persons in one human nature. Thus, by sharing in the same species, many men may be thought of as one man, as Porphyry remarks. Now we should note that in the sin of one man different sins are committed by different members. Nor does the notion of sin require that each sin be voluntary by the will of the members whereby they are committed, but that they be voluntary by the will of that which is principal in man, that is, his intellectual part. For the hand cannot but strike, and the foot cannot help walking, when the will so commands.

In this manner, then, the lack of original justice is a sin of nature in the sense that it has its origin in the inordinate will of the first principle in human nature: namely, of the first parent. And so it is voluntary with respect to nature, that is, by the will of the first principle of nature. And so it is transmitted to all who receive human nature from him, as though to his members. This is why it is called original sin, for it is transferred from the first parent to his descendants by their origin from him. So while other sins, that is, actual sins, have immediately to do with the person sinning, this sin has to do with the nature. For the first parent infected nature by his sin, and nature thus contaminated thereupon infects the persons of the children who receive their nature from the first parent.