This preface, though placed at the beginning, as a preface must be, should be read at the end of the book. I have received a large amount of correspondence concerning this small work, and many reviews of it--some of them nearly as long as the book itself--have been printed. But scarcely any of the comment has been adverse. Some people have objected to a frivolity of tone; but as the tone is not, in my opinion, at all frivolous, this objection did not impress me; and had no we...
