Plutarch, De capienda ex inimicis utilitate
Goodwin, Ed.

Simonides was wont to say that there was no lark without its crest; so the disposition of men is naturally pregnant with strife, suspicion, and envy, which last (as Pindar observes) is ‘the companion of empty-brained men.’ Therefore no man can do any thing that will tend more to his own profit and the preservation of his peace than utterly to purge out of his mind these corrupt affections, and cast them off as the very sink of all iniquity, that they may create no more mischief between him and his friends. This Onomademus, a judicious and wise man, understood well, who, when he was of the prevailing side in a civil commotion at Chios, gave this counsel to his friends, that they should not quite destroy or drive away [p. 296] those of the adverse party, but let some abide there, for fear they should begin to fall out among themselves as soon as their enemies were all out of the way. Therefore, if these uneasy dispositions of the mind be spent and consumed upon enemies, they would never molest or disquiet our friends. Neither doth Hesiod approve of one potter or one singer's envying another, or that a neighbor or relation or brother should resent it ill that another prospers and is successful in the world.¹ But if there be no other way whereby we may be delivered from emulation, envy, or contention, we may suffer our minds to vent these passions upon the prosperity of our enemies, and whet the edge and sharpen the point of our anger upon them. For as gardeners that have knowledge and experience in plants expect their roses and violets should grow the better by being set near leeks and onions,—because all the sour juices of the earth are conveyed into these,—so an enemy by attracting to himself our vicious and peevish qualities, may render us less humorsome and more candid and ingenuous to our friends that are in a better or more happy state than ourselves.

Wherefore let us enter the lists with our enemies, and contend with them for true glory, lawful empire, and just gain. Let us not so much debase ourselves as to be troubled and fret at any possessions they enjoy more than we have. Let us rather carefully observe those good qualities wherein our enemies excel us, so that by these motives we may be excited to outdo them in honest diligence, indefatigable industry, prudent caution, and exemplary sobriety; as Themistocles complained that the victory Miltiades got at Marathon would not let him sleep. But whosoever views his adversary exalted far above him in dignities, in pleading of great causes, in administration of state affairs, or in favor and friendship with princes, and doth not put forth [p. 297] all his strength and power to get before him in these things,—this man commonly pines away, and by degrees sinks into the sloth and misery of an envious and inactive life. And we may observe, that envy and hatred do raise such clouds in the understanding, that a man shall not be able to pass a right judgment concerning things which he hates; but whosoever with an impartial eye beholds, and with a sincere mind judges, the life and manners, discourses, and actions of his enemy, will soon understand that many of those things that raise his envy were gotten by honest care, a discreet providence, and virtuous deeds. Thus the love of honorable and brave actions may be kindled and advanced in him, and an idle and lazy course of life may be contemned and forsaken.