SFORZA, Isabella (1503-1561)- LANDO, Hortensio (1510-1558). Della vera tranquillità dell'animo. Venice: Aldo Manuzio heirs, 1544. Wide-margined copy of the first edition of an important philosophical work by Isabella Sforza, praised by the editor and friend of the author, Hortensio Lando, as an example of extraordinary female literary skill. The work, dedicated to Bishop Otto von Waldburg, focuses on the theme of the tranquillity of the soul and explores ways of achieving it according to classical and Christian traditions. 4to, (215 x 155mm). Aldine device to title page (outer margin of last three leaves anciently remargined to edge of text with fine remake of 5 letters and numbering on each side) 18th century vellum binding with gilt title to spine gilt. (1)