The use of the intercourse of the sexes is for generation. If then such intercourse is to continue after the resurrection, unless it is to continue to no purpose, many men will come to exist after the resurrection, who did not exist before.*
But if any one says that in the risen Saints there will be use of food and sexual intercourse, not for the preservation of the individual and of the species, but solely for the pleasure that goes with such acts, to the end that no pleasure may be lacking in man's final reward, -- such a saying is fraught with many absurdities. In the first place, the life of the risen Saints will be better ordered than our present life. But in this present life it is a disorderly and vicious thing to make use of food and procreation solely for pleasure, and not for the need of sustaining the body or rearing children. For the pleasures that attend such actions are not the ends of those actions, but rather the action is the end and purpose of the pleasure, nature having arranged for pleasure as a concomitant of such actions, lest for the labour that goes with them animals should desist from these actions necessary to nature, as they certainly would desist, were they not enticed by pleasure. It is therefore a perversion of order and an indecency for actions to be done solely for the pleasure that goes with them (B. III, Chap. XXVII). This then shall nowise be the case with the risen Saints, whose life we must assume to be a life of perfect order and propriety. Moreover the notion is ridiculous of seeking bodily pleasures, common to us with brute animals, where there are in view the highest delights, shared with the angels, in the vision of God (B. III, Chap. LI). Hence the Lord says: In the resurrection they shall neither marry nor be given in marriage, but shall be as the angels of God (Matt. xxii, 30).
As for the alleged example of Adam, the perfection of Adam was personal, but human nature was not yet entirely perfect, as the race of mankind was not yet multiplied. Adam then was constituted in the perfection proper to the origin of the human race, for the multiplication of which he needed to beget children, and consequently to make use of food.* But the maturity of the risen state is when human nature shall have come to its full perfection, and the number of the elect shall be complete. Then shall generation no more have place, nor the use of food. Therefore the immortality and incorruption of the risen Saints shall be different from that which was in Adam. The immortality and incorruption of the risen Saints will consist in their being incapable of death, or of the dissolution of any part of their bodily frame. The immortality of Adam consisted in his being capable of immortality, provided he did not sin, and capable of death, if he did sin; and this was secured, not by the prevention of all bodily waste in him, but by the aid of food to counteract an entire dissolution.
The Scripture texts that seem to promise the use of food after the resurrection, are to be understood in a spiritual sense. What is said in the Apocalypse, xx, 4, of the thousand years, is to be understood of the resurrection of souls rising from sin, -- cf. Eph. v, 14, Rise from the dead, and Christ shall enlighten thee; and the thousand years means the whole period of Church history, during which the martyrs reign with Christ, and the other saints, as well in that kingdom of God which is the Church on earth, as in the heavenly country of departed souls.
Hence we may finally conclude that all the activities of the active life shall cease, as they all bear upon the use of food, and the getting of children, and other necessities of a perishable existence. Alone left in the risen Saints shall be the occupation of the contemplative life: wherefore it is said of the contemplative Mary: Mary hath chosen the better part, which shall not be taken from her (Luke x, 42).
4.82 : That Men shall rise again Immortal
4.84 : That Risen Bodies shall be of the same Nature as before