Discours de la Methode pour bien conduire sa Raison, & chercher la Verité dans les Sciences. Plus la Dioptrique, les Meteores, et la Geometrie. Qui sont des essais de cete Methode

Cogito, Ergo Sum in the Court Ballet-Master's Library. First edition of the founding text of modern philosophy, in a strictly contemporary Parisian armorial binding bearing the gilt quartered arms of Louis Hesselin (1602-1662) - maître ordinaire de la Chambre aux deniers, conseiller du Roi, and surintendant des plaisirs du Roi, choreographer of the court ballets in which the young Louis XIV learned to dance, builder (with Le Vau) of the most admired cabinet de curiosités on the Île Saint-Louis, host at Chantemesle to John Evelyn and to Queen Christina of Sweden. Descartes in 1637 had withdrawn from court life to the Netherlands, published his method anonymously, and suppressed its cosmological foundations after the condemnation of Galileo. Hesselin in 1636-37 travelled to Venice and Rome, and from his travels in Italy in the 1630s returned with paintings, objets d'art, and optical instruments. The philosophical method and Hesselin's arms are joined in this copy. Contemporary armorial copies of the Discours with named aristocratic descent are the rarest form in which the book survives; a copy traceable by inscription through six named hands across two and a half centuries is effectively without parallel in the modern trade. Provenance: Louis Hesselin (1602-1662), maître ordinaire de la Chambre aux deniers, conseiller du Roi, and surintendant des plaisirs du Roi, with the gilt quartered arms of Cauchon and Hesselin at the centres and alternating griffin and fleur-de-lys cross tools in the spine compartments (Olivier, Hermal & Roton, XVII, no. 1687); bought from his library at Paris in 1668, with the note 'achepté a Paris de la bibliotheque de Mr Hesselin 1668' on the rear paste-down; Jacques Borde, priest of the diocese of Orléans and canon of the Collégiale Saint-Liphard de Meung-sur-Loire, with his inscription dated 1673 on the rear paste-down and a second, in a larger freer hand, on the front paste-down; Petrus Anianus Douberion, with his mark on the title-page and once on the inside cover, cancelled; Jean-Baptiste Amy-Demeré, professor of rhetoric at the Collège royal d'Orléans, with his inscription dated 1792 on the front paste-down; Eugène Paillet (1829-1901), conseiller at the Cour d'Appel and president of the Société des Amis des Livres, with his Greek leather book-label on the rear paste-down; his sale, Paris, Damascène Morgand, 1902, Part I, lot 60. The Discours is a book that exists only because a larger one could not be. Descartes had been writing Le Monde since October 1629 - a comprehensive natural philosophy founded on the heliocentric hypothesis and designed as his magnum opus, treating everything he believed he knew about material nature: light, the Sun and fixed stars, the heavens, the planets and comets, the Earth, terrestrial bodies, and finally man observing them. The condemnation of Galileo in June 1633 arrested it. Galileo's fate was a legal warning Descartes took seriously: in letters to Mersenne through the autumn of 1633 and spring of 1634 he described the Roman decision as theologically unfounded and politically menacing, and hoped it would be reversed so that Le Monde could be published without fear of censure. It would not be, in his lifetime. He salvaged from the unpublishable work the portions that were theologically survivable - the geometrical optics, the meteorology, and the analytic geometry - and released them four years later as three Essais with a hastily composed methodological preface, anonymously, in Leiden. Posterity has inverted the book's original proportions. What Descartes wrote and conceived as a preface to his science is now read as one of the canonical texts of Western philosophy, while the three Essais it was meant to introduce have lapsed, in the modern handbooks, into what are routinely called its appendices. Yet the Géométrie contains the birth of analytic or coordinate geometry, which Florian Cajori called 'of epoch-making importance' (History of Mathematics, p. 174) and whic.…