18 In my books on Free Will, already referred to, I have said something, not in regard to the variety of capacities in different souls, but, at least, in regard to the pains which infant children suffer in this life. The nature of the opinion which I there expressed, and the reason why it is insufficient for the purposes of our present inquiry, I will now submit to you, and will put into this letter a copy of the passage in the third book to which I refer. It is as follows:— “In connection with the bodily sufferings experienced by the little children who, by reason of their tender age, have no sins— if the souls which animate them did not exist before they were born into the human family— a more grievous and, as it were, compassionate complaint is very commonly made in the remark, 'What evil have they done that they should suffer these things?' as if there could be a meritorious innocence in any one before the time at which it is possible for him to do anything wrong! Moreover, if God accomplishes, in any measure, the correction of the parents when they are chastised by the sufferings or by the death of the children that are dear to them, is there any reason why these things should not take place, seeing that, after they are passed, they will be, to those who experienced them, as if they had never been, while the persons on whose account they were inflicted will either become better, being moved by the rod of temporal afflictions to choose a better mode of life, or be left without excuse under the punishment awarded at the coming judgment, if, notwithstanding the sorrows of this life, they have refused to turn their desires towards eternal life? Morever, who knows what may be given to the little children by means of whose sufferings the parents have their obdurate hearts subdued, or their faith exercised, or their compassion proved? Who knows what good recompense God may, in the secret of his judgments, reserve for these little ones? For although they have done no righteous action, nevertheless, being free from any transgression of their own, they have suffered these trials. It is certainly not without reason that the Church exalts to the honourable rank of martyrs those children who were slain when Herod sought our Lord Jesus Christ to put Him to death.”
19. These things I wrote at that time when I was endeavouring to defend the opinion which is now under discussion. For, as I mentioned shortly before, I was labouring to prove that whichever of these four opinions regarding the soul's incarnation may be found true, the substance of the Creator is absolutely free from blame, and is completely removed from all share in our sins. And, therefore, whichever of these opinions might come to be established or demolished by the truth, this had no bearing on the object aimed at in the work which I was then attempting, seeing that whichever opinion might win the victory over all the rest, after they had been examined in a more thorough discussion, this would take place without causing me any disquietude, because my object then was to prove that, even admitting all these opinions, the doctrine maintained by me remained unshaken. But now my object is, by the force of sound reasoning, to select, if possible, one opinion out of the four; and, therefore, when I carefully consider the words now quoted from that book, I do not see that the arguments there used in defending the opinion which we are now discussing are valid and conclusive.
20. For what may be called the chief prop of my defence is in the sentence, “Moreover, who knows what may be given to the little children, by means of whose sufferings the parents have their obdurate hearts subdued, or their faith exercised, or their compassion proved? Who knows what good recompense God may, in the secret of His judgments, reserve for these little ones?” I see that this is not an unwarranted conjecture in the case of infants who, in any way, suffer (though they know it not) for the sake of Christ and in the cause of true religion, and of infants who have already been made partakers of the sacrament of Christ; because, apart from union to the one Mediator, they cannot be delivered from condemnation, and so put in a position in which it is even possible that a recompense could be made to them for the evils which, in diverse afflictions, they have endured in this world. But since the question cannot be fully solved, unless the answer include also the case of those who, without having received the sacrament of Christian fellowship, die in infancy after enduring the most painful sufferings, what recompense can be conceived of in their case, seeing that, besides all that they suffer in this life, perdition awaits them in the life to come? As to the baptism of infants, I have, in the same book, given an answer, not, indeed, fully, but so far as seemed necessary for the work which then occupied me, proving that it profits children, even though they do not know what it is, and have, as yet, no faith of their own; but on the subject of the perdition of those infants who depart from this life without baptism, I did not think it necessary to say anything then, because the question under discussion was different from that with which we are now engaged.
21. If, however, we pass over and make no account of those sufferings which are of brief continuance, and which, when endured, are not to be repeated, we certainly cannot, in like manner, make no account of the fact that “by one man death came, and by one man came also the resurrection of the dead; for as in Adam all die, even so in Christ shall all be made alive.” For, according to this, divine, and perspicuous declaration, it is sufficiently plain that no one goes to death otherwise than through Adam, and that no one goes to life eternal otherwise than through Christ. For this is the force of all in the two parts of the sentence; as all men, by their first, that is, their natural birth, belong to Adam, even so all men, whoever they be, who come to Christ come to the second, that is, the spiritual birth. For this reason, therefore, the word all is used in both clauses, because as all who die do not die otherwise than in Adam, so all who shall be made alive shall not be made alive otherwise than in Christ. Wherefore whosoever tells us that any man can be made alive in the resurrection of the dead otherwise than in Christ, he is to be detested as a pestilent enemy to the common faith. Likewise, whosoever says that those children who depart out of this life without partaking of that sacrament shall be made alive in Christ, certainly contradicts the apostolic declaration, and condemns the universal Church, in which it is the practice to lose no time and run in haste to administer baptism to infant children, because it is believed, as an indubitable truth, that otherwise they cannot be made alive in Christ. Now he that is not made alive in Christ must necessarily remain under the condemnation, of which the apostle says, that “by the offense of one judgment came upon all men to condemnation.” That infants are born under the guilt of this offense is believed by the whole Church. It is also a doctrine which you have most faithfully set forth, both in your treatise against Jovinian and your exposition of Jonah, as I mentioned above, and, if I am not mistaken, in other parts of your works which I have not read or have at present forgotten. I therefore ask, what is the ground of this condemnation of unbaptized infants? For if new souls are made for men, individually, at their birth, I do not see, on the one hand, that they could have any sin while yet in infancy, nor do I believe, on the other hand, that God condemns any soul which He sees to have no sin.
Source: Letters (New Advent)