Anti-pelagian Writings by St. Augustine
Chapter 20.--Original Sin Alone is Contracted by Natural Birth.
|Moreover the law entered, that the offence might abound.| This addition to original sin men now made of their own wilfulness, not through Adam; but even this is done away and remedied by Christ, because |where sin abounded, grace did much more abound; that as sin hath reigned unto death| -- even that sin which men have not derived from Adam, but have added of their own will -- |even so might grace reign through righteousness unto eternal life.| There is, however, other righteousness apart from Christ, as there are other sins apart from Adam. Therefore, after saying, |As sin hath reigned unto death,| he did not add in the same clause |by one,| or |by Adam,| because he had already spoken of that sin which was abounding when the law entered, and which, of course, was not original sin, but the sin of man's own wilful commission. But after he has said: |Even so might grace also reign through righteousness unto eternal life,| he at once adds, |through Jesus Christ our Lord;| because, whilst by the generation of the flesh only that sin is contracted which is original; yet by the regeneration of the Spirit there is effected the remission not of original sin only, but also of the sins of man's own voluntary and actual commission.