Objection 1. It would seem that the aureole does not differ from the fruit. For different rewards are not due to the same merit. Now the aureole and the hundredfold fruit correspond to the same merit, according to a gloss on Matthew 13:8, "Some a hundredfold." Therefore the aureole is the same as the fruit.
Objection 2. Further, Augustine says (De Virgin xlv) that the "hundredfold fruit is due to the martyrs, and also to virgins." Therefore the fruit is a reward common to virgins and martyrs. But the aureole also is due to them. Therefore the aureole is the same as the fruit.
Objection 3. Further, there are only two rewards in beatitude, namely the essential, and the accidental which is added to the essential. Now that which is added to the essential reward is called an aureole, as evidenced by the statement (Exodus 25:25) that the little crown [aureola] is added to the crown. But the fruit is not the essential reward, for in that case it would be due to all the blessed. Therefore it is the same as the aureole.
On the contrary, Things which are not divided in the same way are not of the same nature. Now fruit and aureole are not divided in the same way, since aureole is divided into the aureole of virgins, of martyrs, and of doctors: whereas fruit is divided into the fruit of the married, of widows, and of virgins. Therefore fruit and aureole are not the same.
Further, if fruit and aureole were the same, the aureole would be due to whomsoever the fruit is due. But this is manifestly untrue, since a fruit is due to widowhood, while an aureole is not. Therefore, etc.
I answer that, Metaphorical expressions can be taken in various ways, according as we find resemblances to the various properties of the thing from which the comparison is taken. Now since fruit, properly speaking, is applied to material things born of the earth, we employ it variously in a spiritual sense, with reference to the various conditions that obtain in material fruits. For the material fruit has sweetness whereby it refreshes so far as it is used by man: again it is the last thing to which the operation of nature attains: moreover it is that to which husbandry looks forward as the result of sowing or any other process. Accordingly fruit is taken in a spiritual sense sometimes for that which refreshes as being the last end: and according to this signification we are said to enjoy [frui] God perfectly in heaven, and imperfectly on the way. From this signification we have fruition which is a dowry: but we are not speaking of fruit in this sense now. Sometimes fruit signifies spiritually that which refreshes only, though it is not the last end; and thus the virtues are called fruits, inasmuch as "they refresh the mind with genuine sweetness," as Ambrose says [De Parad. xiii]. In this sense fruit is taken (Galatians 6:22): "The fruit of the Spirit is charity, joy," etc. Nor again is this the sense in which we speak of fruit now; for we have treated of this already [Cf. I-II, 70, 1, ad 2].
We may, however, take spiritual fruit in another sense, in likeness to material fruit, inasmuch as material fruit is a profit expected from the labor of husbandry: so that we call fruit that reward which man acquires from his labor in this life: and thus every reward which by our labors we shall acquire for the future life is called a "fruit." In this sense fruit is taken (Romans 6:22): "You have your fruit unto sanctification, and the end life everlasting." Yet neither in this sense do we speak of fruit now, but we are treating of fruit as being the product of seed: for it is in this sense that our Lord speaks of fruit (Matthew 13:23), where He divides fruit into thirtyfold, sixtyfold, and hundredfold. Now fruit is the product of seed in so far as the seed power is capable of transforming the humors of the soil into its own nature; and the more efficient this power, and the better prepared the soil, the more plentiful fruit will result. Now the spiritual seed which is sown in us is the Word of God: wherefore the more a person is transformed into a spiritual nature by withdrawing from carnal things, the greater is the fruit of the Word in him. Accordingly the fruit of the Word of God differs from the aurea and the aureole, in that the "aurea" consists in the joy one has in God, and the "aureole" in the joy one has in the perfection of one's works, whereas the "fruit" consists in the joy that the worker has in his own disposition as to his degree of spirituality to which he has attained through the seed of God's Word.
Some, however, distinguish between aureole and fruit, by saying that the aureole is due to the fighter, according to 2 Timothy 2:5, "He... shall not be crowned, except he strive lawfully"; whereas the fruit is due to the laborer, according to the saying of Wisdom 3:15, "The fruit of good labors is glorious." Others again say that the "aurea" regards conversion to God, while the "aureole" and the "fruit" regard things directed to the end; yet so that the fruit regards the will rather, and the aureole the body. Since, however, labor and strife are in the same subject and about the same matter, and since the body's reward depends on the soul's, these explanations of the difference between fruit, aurea and aureole would only imply a logical difference: and this cannot be, since fruit is assigned to some to whom no aureole is assigned.
Reply to Objection 1. There is nothing incongruous if various rewards correspond to the same merit according to the various things contained therein. Wherefore to virginity corresponds the aurea in so far as virginity is kept for God's sake at the command of charity; the aureole, in so far as virginity is a work of perfection having the character of a signal victory; and the fruit, in so far as by virginity a person acquires a certain spirituality by withdrawing from carnal things.
Reply to Objection 2. Fruit, according to the proper acceptation as we are speaking of it now, does not denote the reward common to martyrdom and virginity, by that which corresponds to the three degrees of continency. This gloss which states that the hundredfold fruit corresponds to martyrs takes fruit in a broad sense, according as any reward is called a fruit, the hundredfold fruit thus denoting the reward due to any perfect works whatever.
Reply to Objection 3. Although the aureole is an accidental reward added to the essential reward, nevertheless not every accidental reward is an aureole, but only that which is assigned to works of perfection, whereby man is most conformed to Christ in the achievement of a perfect victory. Hence it is not unfitting that another accidental reward, which is called the fruit, be due sometimes to the withdrawal from a carnal life.
Source: Summa Theologica (New Advent)