OCCULT. - Kenelm DIGBY. Two Treatises, in the One of Which, the Nature of Bodies; in the Other the Nature of Mans Soule is Looked Into; in the Way of Discovery, of the Immortality of Reasonable Soules. Paris: Gilles Blaizot, 1644. Folio (409 x 270mm.) Inscribed on the title-page in ink by the author to his son ('For my Lord Digby'), title-page vignette, woodcut initials, head and tailpieces. (Damp-stain to upper edge, text unaffected, occasional spotting, browning, lacking final blank to rear.) 18th century red morocco, two sets of quadrille fillet gilt with fleurons to corners, seven raised bands to spine, gilt lettering to second compartment, repeating elaborate gilt to the rest, gilt turn-ins, g.e. (rubbing to extremities and surface, replaced endpapers). Note: having studied astrology and alchemy in the 1630's with Van Dyke, Digby became one of the most significant natural philosophers of the age by fusing, in this work, Aristotelianism and Atomism and arguing that the soul was immaterial and therefore immortal. Digby used the mechanical principles developed in this work to underpin many of his writings, including those associated with the occult. The handwritten inscription on the title-page from the author is addressed to his eldest son, also called Kenelm Digby, hence the inscription 'For my Lord Digby'. The book is also formally addressed to his son in the dedication (at aii-ej) and there Digby writes that he has written this, his greatest philosophical work, for his son 'that you may be armed against the worst that may arrive unto you, in this unhappy state of affairs, in our distressed country, I send you these considerations of the nature and Immortality of the human souls which, of late, have been my chief entertainment'. Three years after being presented with this book, Digby's son died in the English civil war, aged twenty-three.