Peter Ruber said this quote

Well, let me try again,' he said. 'If it be true, and no doubt it is, that the proper study of mankind is man, it is also true that man is best studied in the books that he has written about himself; and all books, whatever their subject matter, are in essence autobiographical... Wherefore, it is clear - or is it? - that writers of books are what I have called them, the most fascinating people in the world.