Note 10 — ON THE FOURFOLD ROOT OF THE PRINCIPLE OF SUFFICIENT REASON.

The passage I have quoted above from Schopenhauer's letter is also to be found among the letters published in my book, "Arthur Schopenhauer. Von ihm, über ihn, u. s. w.," p. 541 et seqq., and it results from this, as well as from several other letters which likewise deal with important and knotty points in his philosophy, that this correspondence may perhaps not be quite so worthless and unimportant as many—among them Gwinner, in his pamphlet, "Schopenhauer und seine Freunde" (Leipzig, 1863)—represent it to be. This pamphlet of Gwinner's, by the way, has met with the treatment it deserves in the Preface to the collection, "Aus Arthur Schopenhauer's handschriftlichen Aphorismen und Nachlass. Abhandlungen, Anmerkungen, Fragmente." (Leipzig, 1864).