No man, for any considerable period, can wear one face to himself and another to the multitude, without finally getting bewildered as to which may be the true.

Mathematics is the art of giving the same name to different things.

当今的科学家们思考得很深，而不是很清晰。一个人必须头脑清醒才能清晰地思考，但一个人可以思考得很深却相当疯狂。