Passion also is sometimes reckoned as courage; those who act from passion, like wild beasts rushing at those who have wounded them, are thought to be brave, because brave men also are passionate; for passion above all things is eager to rush on danger, and hence Homer's 'put strength into his passion' and 'aroused their spirit and passion and 'hard he breathed panting' and 'his blood boiled'. For all such expressions seem to indicate the stirring and onset of passion. Now brave men act for honour's sake, but passion aids them; while wild beasts act under the influence of pain; for they attack because they have been wounded or because they are afraid, since if they are in a forest they do not come near one. Thus they are not brave because, driven by pain and passion, they rush on danger without foreseeing any of the perils, since at that rate even asses would be brave when they are hungry; for blows will not drive them from their food; and lust also makes adulterers do many daring things. (Those creatures are not brave, then, which are driven on to danger by pain or passion.) The 'courage' that is due to passion seems to be the most natural, and to be courage if choice and motive be added.The mention of revenge is what first caught my eye, then I had to go back and re-read the first paragraph. (This discussion is of one of five "semblances" of courage Aristotle discusses.) Then I notice the line that such passionate action seems "to be courage if choice and motive is added." This would make it seem that a more pre-meditated form of "revenge"--what we might properly think of revenge, rather than an unreflective striking back--is, or at least seems, courageous.
Men, then, as well as beasts, suffer pain when they are angry, and are pleased when they exact their revenge; those who fight for these reasons, however, are pugnacious but not brave; for they do not act for honour's sake nor as the rule directs, but from strength of feeling; they have, however, something akin to courage. (NE, III, Ch. 8)
This paper by Krisanna Scheiter is very helpful in clarifying what Aristotle means by revenge and what its function is (and that Aristotle would have thought that revenge can take immoral forms). However, she argues that the primary function of revenge (and suggests that this can be seen in Aristotle) is to "right a wrong and to ensure that we are not treated unjustly in the future" (2). I'm not sure how well this fits with Aristotle's claim above that the brave person acts "for honour's sake," since this would suggest that the brave person who engages in an act of revenge does it to restore (protect?) "honour."
Scheiter marks a clear distinction (for Aristotle) between punishment (done for the sake of the wrongdoer, to improve him) and revenge (done for the sake of the wronged, to ensure that they will not be wronged by this person again). So perhaps the idea is that revenge sends the message that one isn't to be f*cked with--and perhaps one's honor is bound up with that 'not-to-be-f*cked-with-ness'. (This would seem to suggest that revenge would only be appropriate when the wrongdoer hadn't already figured that out and/or the person remains a threat. Otherwise, there's no honor, or presumably bravery, in exacting it.)
One interesting point she makes toward the end of the paper is that, "on Aristotle's account, revenge does not have to be severe or violent in order to be effective." That makes me wonder whether there could be a form of "revenge" which, at the same time, doesn't violate Socrates' claim (in Crito) that it's wrong to wrong another, even if we have been wronged (and maybe even if it is violent). It seems this way because it seems like "revenge" here is something like preemptive self-defense. But then it doesn't exactly seem like what we might normally call revenge.
Apply to your favorite cases. Discuss.