Getting angry on behalf of your friends doesn't show love — it shows weakness. What's truly admirable is standing up for your parents, children, friends, and fellow citizens because duty calls you to do so. You act by your own choice, with careful thought, planning ahead. You don't act on impulse or in a frenzy. No emotion wants revenge more than anger does. And that's exactly why anger fails to get revenge. Being too hasty and wild — like most strong desires — it gets in its own way. Anger has never been useful in peace or war. It makes peace feel like war. And when you're actually fighting, anger forgets that fortune can favor either side. It makes you fall into the enemy's power because you've lost control of yourself.
To feel anger on behalf of one’s friends does not show a loving, but a weak mind: it is admirable and worthy conduct to stand forth as the defender of one’s parents, children, friends, and countrymen, at the call of duty itself, acting of one’s own free will, forming a deliberate judgment, and looking forward to the future, not in an impulsive, frenzied fashion. No passion is more eager for revenge than anger, and for that very reason it is unapt to obtain it: being over hasty and frantic, like almost all desires, it hinders itself in the attainment of its own object, and therefore has never been useful either in peace or war: for it makes peace like war, and when in arms forgets that Mars belongs to neither side, and falls into the power of the enemy, because it is not in its own.