Courage (in a soldier) is maintained by a certain anger; anger is a little blind and likes to strike out. And from this follows a thousand abuses, a thousand evils and misfortunes that are impossible to predict in an army during war.

Joseph Joubert (1754-1824) French moralist, philosopher, essayist, poet
Pensées [Thoughts], 1814 entry [tr. Auster (1983)]
    (Source)

I could not find an analog in other translations of the Pensées.