all about Celts; but it is obvious that you know nothing about Irishmen. The Irish are not in the least unsuccessful, unless it is unsuccessful to wander from their own country over a great part of the earth, in which case the English are unsuccessful too." A man with a bumpy head may say to me (as a kind of New Year greeting), "Fools have microcephalous skulls," or what not. To which I shall reply, "In order to be certain of that, you must be a good judge both of the physical and of the mental fact. It is not enough that you should know a microcephalous skull when you see it. It is also necessary that you should know a fool when you see him; and I have a suspicion that you do not know a fool when you see him, even after the most lifelong and intimate of all forms of acquaintanceship."
The trouble with most sociologists, criminologists, etc., is that while their knowledge of their own details is exhaustive and subtle, their knowledge of man and society, to which these are to be applied, is quite exceptionally superficial and silly. They know everything about biology, but almost nothing about life. Their ideas of history, for instance, are simply cheap and uneducated. Thus some famous and foolish professor measured the skull of Charlotte Corday to ascertain the criminal type; he had not historical knowledge