The cardinal virtues are four: temperance, prudence, justice, and courage. Of the four, courage is the most difficult to exercise. Why is that?
Temperance and prudence are virtues of rational self-regard. Anyone who cares about himself and his long-term well-being will be temperate and prudent, whether or not he is just or courageous. This is not to say that the temperate and prudent don't benefit others; they do: The temperate who refrain from drunkenness and drunk driving benefit others by not causing trouble and by setting a good example. The prudent who save and invest do not become a burden on others and are in a position to contribute to charities and make loans to the worthy. This is why it is foolish to glorify the poor and demonize the rich. When was the last time a poor person helped fund a worthy enterprise or gave someone a job?
Temperance and prudence, then, are easy virtues despite the world's being full of the intemperate and imprudent. They are easy in that anyone who values his own life and future will be temperate and prudent. Such a one will not select as his hero the foolish John Belushi (remember him?) who took the Speedball Express to Kingdom Come.
It is harder to be just: to habitually render unto others that which is due them. For the just man must not only be other-regarding and other-respecting; he must be willing and able to discipline his lust, greed, and anger.
But courage is hardest of all. That man is courageous who, mastering his fear, exposes himself to danger for his cause. One thinks of the firefighters who entered the Trade Towers on 9/11, some of whom made the ultimate sacrifice. But Muhammad Atta and his gang were also profiles in courage. Their ends were evil, but that does not detract from the courageousness of their actions. To think otherwise, as so many do, is to fail to grasp the nature of courage.
Courage, then, is the most difficult and the noblest of the cardinal virtues. It is an heroic virtue, a virtue of self-transcendence. By contrast there is nothing heroic about the bourgeois virtues of temperance and prudence.
But now a question is lit in the mind of this aporetic philosopher: Is it prudent to be courageous? Is there an antinomy buried within the bosom of the cardinal virtues? Can there be such a thing as a virtuous man if such a man must have all four of the cardinal virtues?
At most, there is a tension between prudence and courage. But this tension does not spill over into an antinomy. In the virtuous, prudence is subordinated to courage in the sense that, in a situation in which acting courageously is imprudent, one must act courageously.