Notes from Wikiquote
Johnson coincided with me and said, "When a man voluntarily engages in an important controversy, he is to do all he can to lessen his antagonist, because authority from personal respect has much weight with most people, and often more than reasoning. If my antagonist writes bad language, though that may not be essential to the question, I will attack him for his bad language." Adams: "You would not jostle a chimney-sweeper." Johnson: Yes, Sir, if it were necessary to jostle him down."