Lord Chesterfield's niche as the complete 18th-century English aristocrat is due largely to more than 400 letters he wrote to his son, Philip Stanhope. They began when the son was five and continued for more than 30 years, dispensing affection, moral precept, and worldly wisdom in exemplary prose of the day. He wore his learning lightly, as he advises Philip to do in the passage here. Bath, February 22, O.S. 1748
Every excellency, and every virtue, has its kindred vice or weakness; and, if carried beyond certain bounds, sinks into one or the other. Generosity often runs into profusion, economy into avarice, courage into rashness, caution into timidity, and so on: - insomuch that, I believe, there is more judgment required , for the proper conduct of our virtues, than for avoiding their opposite vices. Vice, in its true light, is so deformed, that it shocks us at first sight, and would hardly ever seduce us, if it did not, at first, wear the mask of some virtue. But virtue is, in itself, so beautiful, that it charms us at first sight; engages us more and more upon further acquaintance; and, as with other beauties, we think excess impossible; it is here that judgment is necessary, to moderate and direct the effects of an excellent cause. I shall apply this reasoning, at present, not to any particular virtue, but to an excellency, which , for want of judgment, is often the cause of ridiculous and blamable effects; I mean, great learning; which, if not accompanied with sound judgment, frequently carries us into error, pride, and pedantry. As, I hope, you will possess that excellency in its utmost extent, and yet without its too common failings, the hints which my experience can suggest, may probably not be useless to you.
Some learned men, proud of their knowledge, only speak to decide, and give judgment without appeal; the consequence of which is, that mankind, provoked by the insult, and injured by the oppression, revolt; and, in order to shake off the tyranny, even call the lawful authority in question. The more you know, the modester you should be: and (by the bye) that modesty is the surest way of gratifying your vanity. Even when you are sure, seem rather doubtful; represent, but do not pronounce, and, if you would convince others, seem open to conviction yourself. . . .
If, therefore, you would avoid the accusation of pedantry on one hand, or the suspicion of ignorance on the other, abstain from learned ostentation. Speak the language of the company that you are in; speak it purely, and unlarded with any other. Never seem wiser, nor more learned, than the people you are with. Wear your learning, like your watch, in a private pocket: and do not pull it out and strike it, merely to show that you have one. If you are asked what o'clock it is , tell it; but do not proclaim it hourly and unasked, like the watchman.