Objection 3: Further, the gifts of the Holy Ghost perfect man in the present state of life. But the sight of God does not belong to the present life, since it is that which gives happiness to the Blessed, as stated above (FS, Q[3], A[8]). Therefore the sixth beatitude which comprises the sight of God, does not respond to the gift of understanding.
On the contrary, Augustine says (De Serm. Dom. in Monte i, 4): "The sixth work of the Holy Ghost which is understanding, is applicable to the clean of heart, whose eye being purified, they can see what eye hath not seen."
I answer that, Two things are contained in the sixth beatitude, as also in the others, one by way of merit, viz. cleanness of heart; the other by way of reward, viz. the sight of God, as stated above (FS, Q[69], AA[2] ,4), and each of these, in some way, responds to the gift of understanding.
For cleanness is twofold. One is a preamble and a disposition to seeing God, and consists in the heart being cleansed of inordinate affections: and this cleanness of heart is effected by the virtues and gifts belonging to the appetitive power. The other cleanness of heart is a kind of complement to the sight of God; such is the cleanness of the mind that is purged of phantasms and errors, so as to receive the truths which are proposed to it about God, no longer by way of corporeal phantasms, nor infected with heretical misrepresentations: and this cleanness is the result of the gift of understanding.
Again, the sight of God is twofold. One is perfect, whereby God's Essence is seen: the other is imperfect, whereby, though we see not what God is, yet we see what He is not; and whereby, the more perfectly do we know God in this life, the more we understand that He surpasses all that the mind comprehends. Each of these visions of God belongs to the gift of understanding; the first, to the gift of understanding in its state of perfection, as possessed in heaven; the second, to the gift of understanding in its state of inchoation, as possessed by wayfarers.
This suffices for the Replies to the Objections: for the first two arguments refer to the first kind of cleanness; while the third refers to the perfect vision of God. Moreover the gifts both perfect us in this life by way of inchoation, and will be fulfilled, as stated above (FS, Q[69], A[2]).
Whether faith, among the fruits, responds to the gift of understanding?
Objection 1: It would seem that, among the fruits, faith does not respond to the gift of understanding. For understanding is the fruit of faith, since it is written ( Is. 7:9 ) according to another reading [*The Septuagint]: "If you will not believe you shall not understand," where our version has: "If you will not believe, you shall not continue." Therefore fruit is not the fruit of understanding.
Objection 2: Further, that which precedes is not the fruit of what follows. But faith seems to precede understanding, since it is the foundation of the entire spiritual edifice, as stated above (Q[4], AA[1],7). Therefore faith is not the fruit of understanding.
Objection 3: Further, more gifts pertain to the intellect than to the appetite. Now, among the fruits, only one pertains to the intellect; namely, faith, while all the others pertain to the appetite. Therefore faith, seemingly, does not pertain to understanding more than to wisdom, knowledge or counsel.
On the contrary, The end of a thing is its fruit. Now the gift of understanding seems to be ordained chiefly to the certitude of faith, which certitude is reckoned a fruit. For a gloss on Gal. 5:22 says that the "faith which is a fruit, is certitude about the unseen." Therefore faith, among the fruits, responds to the gift of understanding.
I answer that, The fruits of the Spirit, as stated above (FS, Q[70], A[1]), when we were discussing them, are so called because they are something ultimate and delightful, produced in us by the power of the Holy Ghost. Now the ultimate and delightful has the nature of an end, which is the proper object of the will: and consequently that which is ultimate and delightful with regard to the will, must be, after a fashion, the fruit of all the other things that pertain to the other powers.
Accordingly, therefore, to this kind of gift of virtue that perfects a power, we may distinguish a double fruit: one, belonging to the same power; the other, the last of all as it were, belonging to the will. In this way we must conclude that the fruit which properly responds to the gift of understanding is faith, i.e. the certitude of faith; while the fruit that responds to it last of all is joy, which belongs to the will.
Reply to Objection 1: Understanding is the fruit of faith, taken as a virtue. But we are not taking faith in this sense here, but for a kind of certitude of faith, to which man attains by the gift of understanding.
Reply to Objection 2: Faith cannot altogether precede understanding, for it would be impossible to assent by believing what is proposed to be believed, without understanding it in some way. However, the perfection of understanding follows the virtue of faith: which perfection of understanding is itself followed by a kind of certainty of faith.
Reply to Objection 3: The fruit of practical knowledge cannot consist in that very knowledge, since knowledge of that kind is known not for its own sake, but for the sake of something else. On the other hand, speculative knowledge has its fruit in its very self, which fruit is the certitude about the thing known. Hence the gift of counsel, which belongs only to practical knowledge, has no corresponding fruit of its own: while the gifts of wisdom, understanding and knowledge, which can belongs also to speculative knowledge, have but one corresponding fruit, which is certainly denoted by the name of faith. The reason why there are several fruits pertaining to the appetitive faculty, is because, as already stated, the character of end, which the word fruit implies, pertains to the appetitive rather than to the intellective part.