Thomas Aquinas — on Rom 5:19 (Commentary on Romans)

“Then when he says, for as by the disobedience, the Apostle proves the same thing from something prior. For causes are similar to their effects. But the disobedience of the first parent, which bears the character of injustice, made men sinners and unrighteous. Therefore, the obedience of Christ, which bears the character of justice, made them righteous. And this is what he stated previously, namely, that grace proceeds forth into all men to justification. But there seems to be a problem about the statement that by the disobedience of one man, many were made sinners, i.e., all who are born from his seed. For his first sin seems to have been pride rather than disobedience, as is stated in Sirach: the beginning of every sin is pride (Sir 10:13). In answer it must be noted that the same writer says in Sirach, the beginning of pride makes men separate themselves from God (Sir 10:21), because the first step of pride consists in a man's not willing to be subject to God's precepts, which pertains to disobedience. Hence, man's first sin seems to have been disobedience, not as far as the outward action was concerned but in regard to the inner movement of pride, by which he wills to go against the divine command. Hence, the Lord reproves his disobedience: because you have listened to the voice of your wife and have eaten of the tree of which I commanded you, 'you shall not eat of it,' cursed is the ground (Gen 3:17). On the other hand, Christ's obedience consisted in accepting death for our salvation in accordance with the Father's command: he became obedient unto death (Phil 2:8). This, of course, does not contradict the statement that Christ died out of love for us (Eph 5:2), because the obedience proceeded from the love he had for the Father and for us. And one should note that by obedience and disobedience he proves that through one man we were made sinners and through one man we were justified, because legal justice, which is the ensemble of all virtues, is recognizable in observing the precepts of the law, which pertains to the notion of obedience. But legal injustice, which is the ensemble of all wickedness, is recognizable in transgressing the precepts of the law, which pertains to the notion of disobedience. Consequently, it is fittingly stated that by obedience men were made just and by disobedience sinners.”