Plutarch, De capienda ex inimicis utilitate
Frank Cole Babbitt, Ed.

I observe, my dear Cornelius Pulcher,¹ that you have chosen the mildest form of official administration, in which you are as helpful as possible to the public interests while at the same time you show yourself to be very amiable in private to those who have audience with you. Now it may be possible to find a country, in which, as it is recorded of Crete,² there are no wild animals, but a government which has not had to bear with envy or jealous rivalry or contention—emotions most productive of enmity—has not hitherto existed. For our very friendships, if nothing else, involve us in enmities. This is what the wise Chilon ³ had in mind, when he asked the man who boasted that he had no enemy whether he had no friend either. Therefore it seems to me to be the duty of a statesman not only to have thoroughly investigated the subject of enemies in general, but also in his reading of Xenophon ⁴ to have given more than passing attention to the remark that it is a trait of the man of sense ‘to derive profit even from his enemies.’ Some thoughts, therefore, on this subject, which I recently had occasion to express, I have put together in practically the same words, and now send them to you, with the omission, so far [p. 7] as possible, of matter contained in my Advice to Statesmen,⁵ since I observe that you often have that book close at hand.