Epops: Yet, certainly, the wise learn many things from their enemies; for caution preserves all things. From a friend you could not learn this, but your foe immediately obliges you to learn it. For example, the states have learned from enemies, and not from friends, to build lofty walls, and to possess ships of war. And this lesson preserves children, house, and possessions. Chorus [leader]: It is useful, as it appears to me, to hear their arguments first; for one might learn some wisdom even from one's foes. (tr. Hickie 1853, vol. 1, p. 322; l. 375 identical in SEA 1838, p. 236, and in Bartlett 1968, p. 91 or Archive.org)

A man may learn wisdom even from a foe.

A man can learn wisdom even from a foe

Epops: You're mistaken: men of sense often learn from their enemies. Prudence is the best safeguard. This principle cannot be learned from a friend, but an enemy extorts it immediately. It is from their foes, not their friends, that cities learn the lesson of building high walls and ships of war. And this lesson saves their children, their homes, and their properties. Chorus [leader]: It appears then that it will be better for us to hear what they have to say first; for one may learn something at times even from one's enemies. (tr. Anon. 1812 rev. in Ramage 1864, p. 45)

Men of sense often learn from their enemies. It is from their foes, not their friends, that cities learn the lesson of building high walls and ships of war; and this lesson saves their children, their homes, and their properties.

Even from enemies much can be learned by the intelligent,
More in fact than from our friends.

... men of sense often learn from their enemies. Prudence is the best safeguard. This principle cannot be learned from a friend, but an enemy extorts it immediately. It is from their foes, not their friends, that cities learn the lesson of building high walls and ships of war. And this lesson saves their children, their homes, and their properties.

Epops: The wise can often profit by the lessons of a foe, for caution is the mother of safety. It is just such a thing as one will not learn from a friend and which an enemy compels you to know. To begin with, it's the foe and not the friend that taught cities to build high walls, to equip long vessels of war; and it's this knowledge that protects our children, our slaves and our wealth. Leader of the Chorus [leader]: Well then, I agree, let us first hear them, for that is best; one can even learn something in an enemy's school. (tr. O'Neill 1938, Perseus)

A wise man gets more use from his enemies than a fool from his friends.

The wise man draws more advantage from his enemies than the fool from his friends.

4833. The wise Man draws more Advantage from his Enemies, than a Fool from his Friends.

Fas est ab hoste doceri.
One should learn even from one's enemies.

It occurred to me that if my friends were loathsome, perhaps I needed to learn from my enemies.

5779. Wise Men learn by other Men's Harms ; Fools, by their own.