Summa Theologica, by St. Thomas Aquinas, [1947], at sacred-texts.com
We must next consider the happiness of the saints and their mansions. Under this head there are three points of inquiry:
(1) Whether the happiness of the saints will increase after the judgment?
(2) Whether the degrees of happiness should be called mansions?
(3) Whether the various mansions differ according to various degrees of charity?
Objection 1: It would seem that the happiness of the saints will not be greater after the judgment than before. For the nearer a thing approaches to the Divine likeness, the more perfectly does it participate happiness. Now the soul is more like God when separated from the body than when united to it. Therefore its happiness is greater before being reunited to the body than after.
Objection 2: Further, power is more effective when it is united than when divided. Now the soul is more united when separated from the body than when it is joined to the body. Therefore it has then greater power for operation, and consequently has a more perfect share of happiness, since this consists in action [*Cf. FS, Q[3], A[2]].
Objection 3: Further, beatitude consists in an act of the speculative intellect. Now the intellect, in its act, makes no use of a bodily organ; and consequently by being reunited to the body the soul does not become capable of more perfect understanding. Therefore the soul's happiness is not greater after than before the judgment.
Objection 4: Further, nothing can be greater than the infinite, and so the addition of the finite to the infinite does not result in something greater than the infinite by itself. Now the beatified soul before its reunion with the body is rendered happy by rejoicing in the infinite good, namely God; and after the resurrection of the body it will rejoice in nothing else except perhaps the glory of the body, and this is a finite good. Therefore their joy after the resumption of the body will not be greater than before.
On the contrary, A gloss on Apoc. 6:9, "I saw under the altar the souls of them that were slain," says: "At present the souls of the saints are under the altar, i.e. less exalted than they will be." Therefore their happiness will be greater after the resurrection than after their death.
Further, just as happiness is bestowed on the good as a reward, so is unhappiness awarded to the wicked. But the unhappiness of the wicked after reunion with their bodies will be greater than before, since they will be punished not only in the soul but also in the body. Therefore the happiness of the saints will be greater after the resurrection of the body than before.
I answer that, It is manifest that the happiness of the saints will increase in extent after the resurrection, because their happiness will then be not only in the soul but also in the body. Moreover, the soul's happiness also will increase in extent, seeing that the soul will rejoice not only in its own good, but also in that of the body. We may also say that the soul's happiness will increase in intensity [*Cf. FS, Q[4], A[5] , ad 5, where St. Thomas retracts this statement]. For man's body may be considered in two ways: first, as being dependent on the soul for its completion; secondly, as containing something that hampers the soul in its operations, through the soul not perfectly completing the body. As regards the first way of considering the body, its union with the soul adds a certain perfection to the soul, since every part is imperfect, and is completed in its whole; wherefore the whole is to the part as form to matter. Consequently the soul is more perfect in its natural being, when it is in the whole---namely, man who results from the union of soul and body---than when it is a separate part. But as regards the second consideration the union of the body hampers the perfection of the soul, wherefore it is written (Wis. 9:15) that "the corruptible body is a load upon the soul." If, then, there be removed from the body all those things wherein it hampers the soul's action, the soul will be simply more perfect while existing in such a body than when separated therefrom. Now the more perfect a thing is in being, the more perfectly is it able to operate: wherefore the operation of the soul united to such a body will be more perfect than the operation of the separated soul. But the glorified body will be a body of this description, being altogether subject to the spirit. Therefore, since beatitude consists in an operation [*Cf. FS, Q[3], A[2], seqq.], the soul's happiness after its reunion with the body will be more perfect than before. For just as the soul separated from a corruptible body is able to operate more perfectly than when united thereto, so after it has been united to a glorified body, its operation will be more perfect than while it was separated. Now every imperfect thing desires its perfection. Hence the separated soul naturally desires reunion with the body and on account of this desire which proceeds from the soul's imperfection its operation whereby it is borne towards God is less intense. This agrees with the saying of Augustine (Gen. ad lit. xii, 35) that "on account of the body's desire it is held back from tending with all its might to that sovereign good."
Reply to Objection 1: The soul united to a glorified body is more like to God than when separated therefrom, in so far as when united it has more perfect being. For the more perfect a thing is the more it is like to God: even so the heart, the perfection of whose life consists in movement, is more like to God while in movement than while at rest, although God is never moved.
Reply to Objection 2: A power which by its own nature is capable of being in matter is more effective when subjected in matter than when separated from matter, although absolutely speaking a power separate from matter is more effective.
Reply to Objection 3: Although in the act of understanding the soul does not make use of the body, the perfection of the body will somewhat conduce to the perfection of the intellectual operation in so far as through being united to a glorified body, the soul will be more perfect in its nature, and consequently more effective in its operation, and accordingly the good itself of the body will conduce instrumentally, as it were, to the operation wherein happiness consists: thus the Philosopher asserts (Ethic. i, 8,10) that external goods conduce instrumentally to the happiness of life.
Reply to Objection 4: Although finite added to infinite does not make a greater thing, it makes more things, since finite and infinite are two things, while infinite taken by itself is one. Now the greater extent of joy regards not a greater thing but more things. Wherefore joy is increased in extent, through referring to God and to the body's glory, in comparison with the joy which referred to God. Moreover, the body's glory will conduce to the intensity of the joy that refers to God, in so far as it will conduce to the more perfect operation whereby the soul tends to God: since the more perfect is a becoming operation, the greater the delight [*Cf. FS, Q[32], A[1]], as stated in Ethic. x, 8.
Objection 1: It would seem that the degrees of beatitude should not be called mansions. For beatitude implies the notion of a reward: whereas mansion denotes nothing pertaining to a reward. Therefore the various degrees of beatitude should not be called mansions.
Objection 2: Further, mansion seemingly denotes a place. Now the place where the saint will be beatified is not corporeal but spiritual, namely God Who is one. Therefore there is but one mansion: and consequently the various degrees of beatitude should not be called mansions.
Objection 3: Further, as in heaven there will be men of various merits, so are there now in purgatory, and were in the limbo of the fathers. But various mansions are not distinguished in purgatory and limbo. Therefore in like manner neither should they be distinguished in heaven.
On the contrary, It is written (Jn. 14:2): "In My Father's house there are many mansions": and Augustine expounds this in reference to the different degrees of rewards (Tract. lxvii in Joan.).
Further, in every well-ordered city there is a distinction of mansions. Now the heavenly kingdom is compared to a city (Apoc. 21:2). Therefore we should distinguish various mansions there according to the various degrees of beatitude.
I answer that, Since local movement precedes all other movements, terms of movement, distance and the like are derived from local movement to all other movements according to the Philosopher (Phys., liber viii, 7). Now the end of local movement is a place, and when a thing has arrived at that place it remains there at rest and is maintained therein. Hence in every movement this very rest at the end of the movement is called an establishment [collocatio] or mansion. Wherefore since the term movement is transferred to the actions of the appetite and will, the attainment of the end of an appetitive movement is called a mansion or establishment: so that the unity of a house corresponds to the unity of beatitude which unity is on the part of the object, and the plurality of mansions corresponds to the differences of beatitude on the part of the blessed: even so we observe in natural things that there is one same place above to which all light objects tend, whereas each one reaches it more closely, according as it is lighter, so that they have various mansions corresponding to their various lightness.
Reply to Objection 1: Mansion implies the notion of end and consequently of reward which is the end of merit.
Reply to Objection 2: Though there is one spiritual place, there are different degrees of approaching thereto: and the various mansions correspond to these.
Reply to Objection 3: Those who were in limbo or are now in purgatory have not yet attained to their end. Wherefore various mansions are not distinguished in purgatory or limbo, but only in heaven and hell, wherein is the end of the good and of the wicked.
Objection 1: It would seem that the various mansions are not distinguished according to the various degrees of charity. For it is written (Mat. 25:15): "He gave to every one according to his proper virtue [Douay: 'ability']." Now the proper ability of a thing is its natural power. Therefore the gifts also of grace and glory are distributed according to the different degrees of natural power.
Objection 2: Further, it is written (Ps. 61:12): "Thou wilt render to every man according to his works." Now that which is rendered is the measure of beatitude. Therefore the degrees of beatitude are distinguished according to the diversity of works and not according to the diversity of charity.
Objection 3: Further, reward is due to act and not to habit: hence "it is not the strongest who are crowned but those who engage in the conflict" (Ethic. i, 8) and "he . . . shall not be [Vulg.: 'is not'] crowned except he strive lawfully." Now beatitude is a reward. Therefore the various degrees of beatitude will be according to the various degrees of works and not according to the various degrees of charity.
On the contrary, The more one will be united to God the happier will one be. Now the measure of charity is the measure of one's union with God. Therefore the diversity of beatitude will be according to the difference of charity.
Further, "if one thing simply follows from another thing simply, the increase of the former follows from the increase of the latter." Now to have beatitude follows from having charity. Therefore to have greater beatitude follows from having greater charity.
I answer that, The distinctive principle of the mansions or degrees of beatitude is twofold, namely proximate and remote. The proximate principle is the difference of disposition which will be in the blessed, whence will result the difference of perfection in them in respect to the beatific operation: while the remote principle is the merit by which they have obtained that beatitude. In the first way the mansions are distinguished according to the charity of heaven, which the more perfect it will be in any one, the more will it render him capable of the Divine clarity, on the increase of which will depend the increase in perfection of the Divine vision. In the second way the mansions are distinguished according to the charity of the way. For our actions are meritorious, not by the very substance of the action, but only by the habit of virtue with which they are informed. Now every virtue obtains its meritorious efficacy from charity [*Cf. FS, Q[114], A[4]], which has the end itself for its object [*Cf. SS, Q[24], A[3], ad 1]. Hence the diversity of merit is all traced to the diversity of charity, and thus the charity of the way will distinguish the mansions by way of merit.
Reply to Objection 1: In this passage "virtue" denotes not the natural ability alone, but the natural ability together with the endeavour to obtain grace [*Cf. SS, Q[23], A[8]]. Consequently virtue in this sense will be a kind of material disposition to the measure of grace and glory that one will receive. But charity is the formal complement of merit in relation to glory, and therefore the distinction of degrees in glory depends on the degrees of charity rather than on the degrees of the aforesaid virtue.
Reply to Objection 2: Works in themselves do not demand the payment of a reward, except as informed by charity: and therefore the various degrees of glory will be according to the various degrees of charity.
Reply to Objection 3: Although the habit of charity or of any virtue whatever is not a merit to which a reward is due, it is none the less the principle and reason of merit in the act: and consequently according to its diversity is the diversity of rewards. This does not prevent our observing a certain degree of merit in the act considered generically, not indeed in relation to the essential reward which is joy in God, but in relation to some accidental reward, which is joy in some created good.