Wise anger is like fire from a flint: there is great ado to get it out and when it does come, it is out again immediately.

Hale’s simile contrasts impulsive rage with what he calls “wise anger”: a controlled, principled indignation that is difficult to kindle and quick to subside. Like a spark struck from flint, it requires effort and purpose to produce—suggesting that a thoughtful person does not flare up easily. Yet once the necessary point has been made (or the moral energy released), it vanishes at once, implying restraint, self-command, and an unwillingness to nurse resentment. The image also hints that anger can be useful—providing momentary heat or light—so long as it remains brief and governed by judgment rather than ego.