Reply to Objection 1: As the Philosopher says (Ethic. x, 4) "delight perfects operation as vigor perfects youth," because it is a result of youth. Consequently delight is a perfection attendant upon vision; but not a perfection whereby vision is made perfect in its own species.
Reply to Objection 2: The apprehension of the senses does not attain to the universal good, but to some particular good which is delightful. And consequently, according to the sensitive appetite which is in animals, operations are sought for the sake of delight. But the intellect apprehends the universal good, the attainment of which results in delight: wherefore its purpose is directed to good rather than to delight. Hence it is that the Divine intellect, which is the Author of nature, adjusted delights to operations on account of the operations. And we should form our estimate of things not simply according to the order of the sensitive appetite, but rather according to the order of the intellectual appetite.
Reply to Objection 3: Charity does not seem the beloved good for the sake of delight: it is for charity a consequence that it delights in the good gained which it loves. Thus delight does not answer to charity as its end, but vision does, whereby the end is first made present to charity.
Whether comprehension is necessary for happiness?
Objection 1: It would seem that comprehension is not necessary for happiness. For Augustine says (Ad Paulinam de Videndo Deum; [*Cf. Serm. xxxciii De Verb. Dom.]): "To reach God with the mind is happiness, to comprehend Him is impossible." Therefore happiness is without comprehension.
Objection 2: Further, happiness is the perfection of man as to his intellective part, wherein there are no other powers than the intellect and will, as stated in the FP, QQ[79] and following. But the intellect is sufficiently perfected by seeing God, and the will by enjoying Him. Therefore there is no need for comprehension as a third.
Objection 3: Further, happiness consists in an operation. But operations are determined by their objects: and there are two universal objects, the true and the good: of which the true corresponds to vision, and good to delight. Therefore there is no need for comprehension as a third.
On the contrary, The Apostle says ( 1 Cor. 9:24 ): "So run that you may comprehend [Douay: 'obtain']." But happiness is the goal of the spiritual race: hence he says ( 2 Tim. 4:7 , 8 ): "I have fought a good fight, I have finished my course, I have kept the faith; as to the rest there is laid up for me a crown of justice." Therefore comprehension is necessary for Happiness.
I answer that, Since Happiness consists in gaining the last end, those things that are required for Happiness must be gathered from the way in which man is ordered to an end. Now man is ordered to an intelligible end partly through his intellect, and partly through his will: through his intellect, in so far as a certain imperfect knowledge of the end pre-exists in the intellect: through the will, first by love which is the will's first movement towards anything; secondly, by a real relation of the lover to the thing beloved, which relation may be threefold. For sometimes the thing beloved is present to the lover: and then it is no longer sought for. Sometimes it is not present, and it is impossible to attain it: and then, too, it is not sought for. But sometimes it is possible to attain it, yet it is raised above the capability of the attainer, so that he cannot have it forthwith; and this is the relation of one that hopes, to that which he hopes for, and this relation alone causes a search for the end. To these three, there are a corresponding three in Happiness itself. For perfect knowledge of the end corresponds to imperfect knowledge; presence of the end corresponds to the relation of hope; but delight in the end now present results from love, as already stated (A[2], ad 3). And therefore these three must concur with Happiness; to wit, vision, which is perfect knowledge of the intelligible end; comprehension, which implies presence of the end; and delight or enjoyment, which implies repose of the lover in the object beloved.
Reply to Objection 1: Comprehension is twofold. First, inclusion of the comprehended in the comprehensor; and thus whatever is comprehended by the finite, is itself finite. Wherefore God cannot be thus comprehended by a created intellect. Secondly, comprehension means nothing but the holding of something already present and possessed: thus one who runs after another is said to comprehend [*In English we should say 'catch.'] him when he lays hold on him. And in this sense comprehension is necessary for Happiness.
Reply to Objection 2: Just as hope and love pertain to the will, because it is the same one that loves a thing, and that tends towards it while not possessed, so, too, comprehension and delight belong to the will, since it is the same that possesses a thing and reposes therein.
Reply to Objection 3: Comprehension is not a distinct operation from vision; but a certain relation to the end already gained. Wherefore even vision itself, or the thing seen, inasmuch as it is present, is the object of comprehension.
Whether rectitude of the will is necessary for happiness?
Objection 1: It would seem that rectitude of the will is not necessary for Happiness. For Happiness consists essentially in an operation of the intellect, as stated above (Q[3], A[4]). But rectitude of the will, by reason of which men are said to be clean of heart, is not necessary for the perfect operation of the intellect: for Augustine says (Retract. i, 4) "I do not approve of what I said in a prayer: O God, Who didst will none but the clean of heart to know the truth. For it can be answered that many who are not clean of heart, know many truths." Therefore rectitude of the will is not necessary for Happiness.
Objection 2: Further, what precedes does not depend on what follows. But the operation of the intellect precedes the operation of the will. Therefore Happiness, which is the perfect operation of the intellect, does not depend on rectitude of the will.
Objection 3: Further, that which is ordained to another as its end, is not necessary, when the end is already gained; as a ship, for instance, after arrival in port. But rectitude of will, which is by reason of virtue, is ordained to Happiness as to its end. Therefore, Happiness once obtained, rectitude of the will is no longer necessary.
On the contrary, It is written ( Mat. 5:8 ): "Blessed are the clean of heart; for they shall see God": and ( Heb. 12:14 ): "Follow peace with all men, and holiness; without which no man shall see God."
I answer that, Rectitude of will is necessary for Happiness both antecedently and concomitantly. Antecedently, because rectitude of the will consists in being duly ordered to the last end. Now the end in comparison to what is ordained to the end is as form compared to matter. Wherefore, just as matter cannot receive a form, unless it be duly disposed thereto, so nothing gains an end, except it be duly ordained thereto. And therefore none can obtain Happiness, without rectitude of the will. Concomitantly, because as stated above (Q[3], A[8]), final Happiness consists in the vision of the Divine Essence, Which is the very essence of goodness. So that the will of him who sees the Essence of God, of necessity, loves, whatever he loves, in subordination to God; just as the will of him who sees not God's Essence, of necessity, loves whatever he loves, under the common notion of good which he knows. And this is precisely what makes the will right. Wherefore it is evident that Happiness cannot be without a right will.
Reply to Objection 2: Every act of the will is preceded by an act of the intellect: but a certain act of the will precedes a certain act of the intellect. For the will tends to the final act of the intellect which is happiness. And consequently right inclination of the will is required antecedently for happiness, just as the arrow must take a right course in order to strike the target.
Reply to Objection 3: Not everything that is ordained to the end, ceases with the getting of the end: but only that which involves imperfection, such as movement. Hence the instruments of movement are no longer necessary when the end has been gained: but the due order to the end is necessary.
Whether the body is necessary for man's happiness?
Objection 1: It would seem that the body is necessary for Happiness. For the perfection of virtue and grace presupposes the perfection of nature. But Happiness is the perfection of virtue and grace. Now the soul, without the body, has not the perfection of nature; since it is naturally a part of human nature, and every part is imperfect while separated from its whole. Therefore the soul cannot be happy without the body.
Objection 2: Further, Happiness is a perfect operation, as stated above (Q[3], AA[2],5). But perfect operation follows perfect being: since nothing operates except in so far as it is an actual being. Since, therefore, the soul has not perfect being, while it is separated from the body, just as neither has a part, while separate from its whole; it seems that the soul cannot be happy without the body.
Objection 3: Further, Happiness is the perfection of man. But the soul, without the body, is not man. Therefore Happiness cannot be in the soul separated from the body.
Objection 4: Further, according to the Philosopher (Ethic. vii, 13) "the operation of bliss," in which operation happiness consists, is "not hindered." But the operation of the separate soul is hindered; because, as Augustine says (Gen. ad lit. xii, 35), the soul "has a natural desire to rule the body, the result of which is that it is held back, so to speak, from tending with all its might to the heavenward journey," i.e. to the vision of the Divine Essence. Therefore the soul cannot be happy without the body.