On the contrary, Augustine [*Paterius, Expos. Vet. et Nov. Test. super Ex. 40] says: "Increase of merit was absolutely impossible to the soul of Christ." But increase of merit would have been possible had He not merited in the first instant of His conception. Therefore Christ merited in the first instant of His conception.
I answer that, As stated above (A. 1), Christ was sanctified by grace in the first instant of His conception. Now, sanctification is twofold: that of adults who are sanctified in consideration of their own act; and that of infants who are sanctified in consideration of, not their own act of faith, but that of their parents or of the Church. The former sanctification is more perfect than the latter: just as act is more perfect than habit; and "that which is by itself, than that which is by another" [*Aristotle, Phys. viii]. Since, therefore, the sanctification of Christ was most perfect, because He was so sanctified that He might sanctify others; consequently He was sanctified by reason of His own movement of the free-will towards God. Which movement, indeed, of the free-will is meritorious. Consequently, Christ did merit in the first instant of His conception.
Reply Obj. 1: Free-will does not bear the same relation to good as to evil: for to good it is related of itself, and naturally; whereas to evil it is related as to a defect, and beside nature. Now, as the Philosopher says (De Coelo ii, text. 18): "That which is beside nature is subsequent to that which is according to nature; because that which is beside nature is an exception to nature." Therefore the free-will of a creature can be moved to good meritoriously in the first instant of its creation, but not to evil sinfully; provided, however, its nature be unimpaired.
Reply Obj. 2: That which man has at the first moment of his creation, in the ordinary course of nature, is natural to him; but nothing hinders a creature from receiving from God a gift of grace at the very beginning of its creation. In this way did Christ's soul in the first instant of its creation receive grace by which it could merit. And for this reason is that grace, by way of a certain likeness, said to be natural to this Man, as explained by Augustine (Enchiridion xl).
Reply Obj. 3: Nothing prevents the same thing belonging to someone from several causes. And thus it is that Christ was able by subsequent actions and sufferings to merit the glory of immortality, which He also merited in the first instant of His conception: not, indeed, so that it became thereby more due to Him than before, but so that it was due to Him from more causes than before. _______________________
FOURTH ARTICLE [III, Q. 34, Art. 4]
Whether Christ Was a Perfect Comprehensor in the First Instant of His
Conception?
Objection 1: It would seem that Christ was not a perfect comprehensor in the first instant of His conception. For merit precedes reward, as fault precedes punishment. But Christ merited in the first instant of His conception, as stated above (A. 3). Since, therefore, the state of comprehension is the principal reward, it seems that Christ was not a comprehensor in the first instant of His conception.
Obj. 2: Further, our Lord said (Luke 24:26): "Ought not Christ to have suffered these things, and so to enter into His glory?" But glory belongs to the state of comprehension. Therefore Christ was not in the state of comprehension in the first instant of His conception, when as yet He had not suffered.
Obj. 3: Further, what befits neither man nor angel seems proper to God; and therefore is not becoming to Christ as man. But to be always in the state of beatitude befits neither man nor angel: for if they had been created in beatitude, they would not have sinned afterwards. Therefore Christ, as man, was not in the state of beatitude in the first instant of His conception.