DESCARTES, René (1596-1650). Lettres... touchant la morale, physique, médecine & les mathematiques, Paris: Charles Angot, 1666-67, 3 vols., 4°, new enlarged edition, vignette to each title, woodcut illustrations (leaves slightly browned, library stamps), contemporary mottled calf (head and tail of spines chipped, spine of vol. III split, slight damage to spine of vol. I, corners bumped). [Guibert, p. 85] Provenance: Thomas, Earl of Stratford 1712; JCL; Opuscula posthuma, physica et mathematica, Amsterdam: Janssonius-Waesbergios, Boom & Goethals, 1701, 4°, FIRST EDITION, illustrations, vignette to title (slightly spotted, library stamps), contemporary vellum, manuscript title to spine (spine slightly soiled). [Guibert, p. 221] Provenance: JCL; Opera Philosophica, Amsterdam: Blaviana, 1685-1686, 5 vols. in one, 4°, editio ultima, woodcut illustrations (title loose, slight marginal dampstaining, some leaves slightly browned, library stamps), contemporary calf (manuscript inscription to spine, spine soiled). [Guibert, p. 232] Provenance: JCL; with one other work by Descartes (16)