Objection 1. It seems that the brave man delights in his act. For "delight is the unhindered action of a connatural habit" (Ethic. x, 4,6,8). Now the brave deed proceeds from a habit which acts after the manner of nature. Therefore the brave man takes pleasure in his act.
Objection 2. Further, Ambrose, commenting on Galatians 5:22, "But the fruit of the Spirit is charity, joy, peace," says that deeds of virtue are called "fruits because they refresh man's mind with a holy and pure delight." Now the brave man performs acts of virtue. Therefore he takes pleasure in his act.
Objection 3. Further, the weaker is overcome by the stronger. Now the brave man has a stronger love for the good of virtue than for his own body, which he exposes to the danger of death. Therefore the delight in the good of virtue banishes the pain of the body; and consequently the brave man does all things with pleasure.
On the contrary, The Philosopher says (Ethic. iii, 9) that "the brave man seems to have no delight in his act."
I answer that, As stated above (I-II, 31, 3,4,5) where we were treating of the passions, pleasure is twofold; one is bodily, resulting from bodily contact, the other is spiritual, resulting from an apprehension of the soul. It is the latter which properly results from deeds of virtue, since in them we consider the good of reason. Now the principal act of fortitude is to endure, not only certain things that are unpleasant as apprehended by the soul--for instance, the loss of bodily life, which the virtuous man loves not only as a natural good, but also as being necessary for acts of virtue, and things connected with them--but also to endure things unpleasant in respect of bodily contact, such as wounds and blows. Hence the brave man, on one side, has something that affords him delight, namely as regards spiritual pleasure, in the act itself of virtue and the end thereof: while, on the other hand, he has cause for both spiritual sorrow, in the thought of losing his life, and for bodily pain. Hence we read (2 Maccabees 6:30) that Eleazar said: "I suffer grievous pains in body: but in soul am well content to suffer these things because I fear Thee."
Now the sensible pain of the body makes one insensible to the spiritual delight of virtue, without the copious assistance of God's grace, which has more strength to raise the soul to the Divine things in which it delights, than bodily pains have to afflict it. Thus the Blessed Tiburtius, while walking barefoot on the burning coal, said that he felt as though he were walking on roses.
Yet the virtue of fortitude prevents the reason from being entirely overcome by bodily pain. And the delight of virtue overcomes spiritual sorrow, inasmuch as a man prefers the good of virtue to the life of the body and to whatever appertains thereto. Hence the Philosopher says (Ethic. ii, 3; iii, 9) that "it is not necessary for a brave man to delight so as to perceive his delight, but it suffices for him not to be sad."
Reply to Objection 1. The vehemence of the action or passion of one power hinders the action of another power: wherefore the pain in his senses hinders the mind of the brave man from feeling delight in its proper operation.
Reply to Objection 2. Deeds of virtue are delightful chiefly on account of their end; yet they can be painful by their nature, and this is principally the case with fortitude. Hence the Philosopher says (Ethic. iii, 9) that "to perform deeds with pleasure does not happen in all virtues, except in so far as one attains the end."
Reply to Objection 3. In the brave man spiritual sorrow is overcome by the delight of virtue. Yet since bodily pain is more sensible, and the sensitive apprehension is more in evidence to man, it follows that spiritual pleasure in the end of virtue fades away, so to speak, in the presence of great bodily pain.
Source: Summa Theologica (New Advent)