Weininger, Otto Geschlecht und Charakter: Eine prinzipielle Untersuchung. Vienna: Wilhelm Braumüller, Universitätsbuchhandlung, 1926. First edition of the popular edition (Volksausgabe) of this landmark study of human sexuality, with a facsimile of an unpublished letter from Weininger to Hermann Swoboda discussing Peer Gynt. 336 pages. Volume is bound in orange cloth backstrip and printed paper-covered boards. Book shows light shelfwear. Binding is firm. Pages are clean and without markings.