Objection 1. It would seem that not every punishment is inflicted for a sin. For it is written (John 9:3,2) about the man born blind: "Neither hath this man sinned, nor his parents... that he should be born blind." In like manner we see that many children, those also who have been baptized, suffer grievous punishments, fevers, for instance, diabolical possession, and so forth, and yet there is no sin in them after they have been baptized. Moreover before they are baptized, there is no more sin in them than in the other children who do not suffer such things. Therefore not every punishment is inflicted for a sin.
Objection 2. Further, that sinners should thrive and that the innocent should be punished seem to come under the same head. Now each of these is frequently observed in human affairs, for it is written about the wicked (Psalm 72:5): "They are not in the labor of men: neither shall they be scourged like other men"; and (Job 21:7): "[Why then do] the wicked live, are [they] advanced, and strengthened with riches" (?)[The words in brackets show the readings of the Vulgate]; and (Habakkuk 1:13): "Why lookest Thou upon the contemptuous [Vulgate: 'them that do unjust things'], and holdest Thy peace, when the wicked man oppresseth [Vulgate: 'devoureth'], the man that is more just than himself?" Therefore not every punishment is inflicted for a sin.
Objection 3. Further, it is written of Christ (1 Peter 2:22) that "He did no sin, nor was guile found in His mouth." And yet it is said (1 Peter 2:21) that "He suffered for us." Therefore punishment is not always inflicted by God for sin.
On the contrary, It is written (Job 4:7, seqq.): "Who ever perished innocent? Or when were the just destroyed?
On the contrary, I have seen those who work iniquity... perishing by the blast of God"; and Augustine writes (Retract. i) that "all punishment is just, and is inflicted for a sin."
I answer that, As already stated (6), punishment can be considered in two ways--simply, and as being satisfactory. A satisfactory punishment is, in a way, voluntary. And since those who differ as to the debt of punishment, may be one in will by the union of love, it happens that one who has not sinned, bears willingly the punishment for another: thus even in human affairs we see men take the debts of another upon themselves. If, however, we speak of punishment simply, in respect of its being something penal, it has always a relation to a sin in the one punished. Sometimes this is a relation to actual sin, as when a man is punished by God or man for a sin committed by him. Sometimes it is a relation to original sin: and this, either principally or consequently--principally, the punishment of original sin is that human nature is left to itself, and deprived of original justice: and consequently, all the penalties which result from this defect in human nature.
Nevertheless we must observe that sometimes a thing seems penal, and yet is not so simply. Because punishment is a species of evil, as stated in the I, 48, 5. Now evil is privation of good. And since man's good is manifold, viz. good of the soul, good of the body, and external goods, it happens sometimes that man suffers the loss of a lesser good, that he may profit in a greater good, as when he suffers loss of money for the sake of bodily health, or loss of both of these, for the sake of his soul's health and the glory of God. In such cases the loss is an evil to man, not simply but relatively; wherefore it does not answer to the name of punishment simply, but of medicinal punishment, because a medical man prescribes bitter potions to his patients, that he may restore them to health. And since such like are not punishments properly speaking, they are not referred to sin as their cause, except in a restricted sense: because the very fact that human nature needs a treatment of penal medicines, is due to the corruption of nature which is itself the punishment of original sin. For there was no need, in the state of innocence, for penal exercises in order to make progress in virtue; so that whatever is penal in the exercise of virtue, is reduced to original sin as its cause.
Reply to Objection 1. Such like defects of those who are born with them, or which children suffer from, are the effects and the punishments of original sin, as stated above (Question 85, Article 5); and they remain even after baptism, for the cause stated above (85, 5, ad 2): and that they are not equally in all, is due to the diversity of nature, which is left to itself, as stated above (85, 5, ad 1). Nevertheless, they are directed by Divine providence, to the salvation of men, either of those who suffer, or of others who are admonished by their means--and also to the glory of God.
Reply to Objection 2. Temporal and bodily goods are indeed goods of man, but they are of small account: whereas spiritual goods are man's chief goods. Consequently it belongs to Divine justice to give spiritual goods to the virtuous, and to award them as much temporal goods or evils, as suffices for virtue: for, as Dionysius says (Div. Nom. viii), "Divine justice does not enfeeble the fortitude of the virtuous man, by material gifts." The very fact that others receive temporal goods, is detrimental to their spiritual good; wherefore the psalm quoted concludes (verse 6): "Therefore pride hath held them fast."
Reply to Objection 3. Christ bore a satisfactory punishment, not for His, but for our sins.
Source: Summa Theologica (New Advent)