Anti-pelagian Writings by St. Augustine
Chapter 9 [IX.]--Sin Passes on to All Men by Natural Descent, and Not Merely by Imitation.
You tell me in your letter, that they endeavour to twist into some new sense the passage of the apostle, in which he says: |By one man sin entered into the world, and death by sin;| yet you have not informed me what they suppose to be the meaning of these words. But so far as I have discovered from others, they think that the death which is here mentioned is not the death of the body, which they will not allow Adam to have deserved by his sin, but that of the soul, which takes place in actual sin; and that this actual sin has not been transmitted from the first man to other persons by natural descent, but by imitation. Hence, likewise, they refuse to believe that in infants original sin is remitted through baptism, for they contend that no such original sin exists at all in people by their birth. But if the apostle had wished to assert that sin entered into the world, not by natural descent, but by imitation, he would have mentioned as the first offender, not Adam indeed, but the devil, of whom it is written, that |he sinneth from the beginning;| of whom also we read in the Book of Wisdom: |Nevertheless through the devil's envy death entered into the world.| Now, forasmuch as this death came upon men from the devil, not because they were propagated by him, but because they imitated his example, it is immediately added: |And they that do hold of his side do imitate him.| Accordingly, the apostle, when mentioning sin and death together, which had passed by natural descent from one upon all men, set him down as the introducer thereof from whom the propagation of the human race took its beginning.