4to, pp. [xl], 222, [xvi], 248, [xxiv], 92, . Contemporary vellum boards, fore-edge extensions, spine lettered in ink, all edges blue. Contemporary ownership inscription neatly clipped from blank area of title-page, lightly browned, a little spotting. Vellum dustsoiled, pastedowns lifting and fore-edge extensions somewhat splayed. Ownership stamp of C. Hennings to title-page, with earlier inscription of A. W. Rekberg, Hannau, 1773 to flyleaf.
The sixth and final Elzevir 'collected works' of Descartes - in fact just three titles, each with their own title-pages but issued together in this form: the Principia Philosophiae, Speciminia Philosophiae: seu dissertatio de Methodo, and Passiones Animae. The table of contents (printed on the verso of the general half-title, from which the title above is taken) also lists the 'Meditationes de Prima Philosophia, &c.' and 'Epistola ad Celeberrimum virum D. Gisbertum Voetium', but these were not published with the rest of the volume - they were issued separately the following year and only rarely found together with this publication.