81. Ep. 166.4.10–6.16 (CSEL 44:530–70); trans. Parsons, FOTC 30:15–22.
Christian sacrament, if new souls, created separately by the will of the Creator, are joined to separate bodies at birth, with no previous sin of their own, souls which He created and gave to animate these bodies, when He certainly knew that each one of them by no fault of its own would leave the body without the baptism of Christ? Since, therefore, we cannot say of God that He either forces souls to become sinful or punishes the innocent, and we must necessarily assert that souls, even those of infants, which leave the body without the sacrament of Christ are subject to damnation, how are we to defend this opinion which holds that other souls do not come into being from that of the first man, but are thus created separately as that first one was? . . .
(6.16) But when I come to the question of the sufferings of infants, believe me, I am greatly upset, and I find no ready answer. I mean not only those suffering what damnation brings after this life and what must necessarily come upon those who leave the body without the grace of the Christian sacrament, but also those who are presented in this life to our grieving eyes, so numerous that the time for narrating it, rather than examples, fails me. They pine away with illness, they are racked with pains, they are tortured with hunger and thirst, they are weak of limb, they are deprived of their faculties, they are tormented by unclean spirits. Certainly, there must be a proof that they suffer all this justly, without any evil cause on their part. It is not permissible to say either that these things happen without God's knowledge, or that He is unable to hinder those who cause them, or that He causes or permits them unjustly. Of irrational animals we say rightly that they are given over to be used by higher beings, even sinful ones, as we see in the Gospel, where the devils were allowed to use the swine for their intended purpose. But how can we rightly say the same of a human being? The human being is an animal, but a rational (though mortal) one. There is a rational soul in his members that pays the penalty by such sufferings. God is good, God is just, God is almighty. Only a madman doubts this. Therefore, a just cause must be assigned to these great sufferings that befall little children. Doubtless, when their elders suffer these afflictions, we are wont to say either that their goodness is being tested, as in the case of Job, or that their sins are being punished, as happened to Herod; and from the examples that God has willed to make clear, it is granted to us to conjecture about other cases that are hard to understand. But these are older people. Tell me what we are to answer about children if there are no sins to be punished in them by such sufferings, since there obviously is no virtue to be tested at their age.81
81. Ep. 166.4.10–6.16 (CSEL 44:530–70); trans. Parsons, FOTC 30:15–22.