Suppose you meet a man who asks you what your field of endeavor is and you tell him that you are the world's greatest living vertebrate paleontologist, which is, of course, what you are. And suppose that, on hearing this, the man you meet fixes you with a glittering eye and proceeds to lecture you for five hours on vertebrate paleontology, getting all his facts wrong, yet somehow leaving you unable to argue them. You will then have met [John W.] Campbell.