Justice Felix Frankfurter told his biographer, Harlan Buddington Phillips, this story about Ralph Waldo Emerson. Emerson had encouraged the young Oliver Wendell Holmes to read Plato. Holmes did, and wrote an essay criticizing the philosopher. Emerson read the essay, and had this to say in response:
“I read your piece on Plato. Holmes, when you strike at a king, you must kill him.