Odo of Tournai’s De peccato originali and the Problem of Original Sin
Resnick, Irven M.
Medieval Philosophy and Theology, vol. 1 (1991)
Although there were early disagreements over the right understanding of original sin and its consequences, a consensus gradually emerged in the Western Church as the outcome of the debates between St. Augustine and the followers of Pelagius early in the fifth century. Pelagius’s disciple Celestius was condemned for the view that Adam’s sin affected only Adam, not the entire human race. Other Pelagians (or semi-Pelagians) reasonably inferred that “If sin is natural, it is not voluntary; if it is voluntary, it is not inborn.
These two definitions are as mutally contrary as are necessity and [free] will.” Since the Pelagians insisted on the voluntary character of sin, it seemed to them impossible that one might be born with sin. Augustine, on the other hand, affirms that original sin is both voluntary and free for Adam, while it is natural and necessary for us. In part this view stems from Augustine’s efforts to safeguard the practice of infant baptism in the Church, which certainly makes sense if there is some inherited sin of which infants must be cleansed.