"A physician is not angry at the intemperance of a mad patient, nor does he take it ill to be railed at by a man in fever. Just so should a wise man treat all mankind, as a physician does his patient, and look upon them only as sick and extravagant"

The quote suggests that a sensible person must always treat everyone with generosity and compassion, even if others behave crazily or do not act in a socially acceptable way. The contrast to a physician and their patient indicates that the sensible individual should see others as being "ill" or bothered, and therefore in requirement of understanding and care. The quote encourages us not to take offense at the actions of others, but rather to act with patience and compassion towards all.