Books

Leiden: Jan Maire, 1637. First edition. 'COGITO, ERGO, SUM' (PMM 129). First edition of Descartes' first and most famous work, and an extremely attractive copy in a strictly contemporary binding with the gilt arms of Louis Treslon-Cauchon, known as Hesselin, one of the most important and distinguished French bibliophiles of the 17th century. Following the Discours, now celebrated as one of the canonical texts of Western philosophy, are three 'Essais', the last of which, La Géométrie, contains the birth of analytical or co-ordinate geometry, "of epoch-making importance" (Cajori, History of Mathematics, p. 174), designated by John Stuart Mill as "the greatest single step ever made in the progress of the exact sciences". It "rendered possible the later achievements of seventeenth-century mathematical physics" (Hall, Nature and nature's laws (1970), p. 91). The first of the Essais, La Dioptrique, contains Descartes' discovery of 'Snell's law' of refraction of light (earlier than…

René Descartes' seminal work, "Discours de la méthode pour bien conduire sa raison, et chercher la vérité dans les sciences plus La Dioptrique, Les Météores et La Géométrie qui sont des essais de cette Méthode," commonly known as "Discourse on the Method," represents a monumental shift in the approach towards scientific and philosophical inquiry. First published in 1637, it not only laid down the foundation for modern philosophy but also introduced a new methodological approach to science, emphasizing reason and observation over medieval traditions and Aristotelian scholasticism. This essay seeks to explore the core components and the overarching impact of Descartes' work, delineating its significance in the annals of Western thought. At the heart of "Discourse on the Method" is Descartes' advocacy for methodical skepticism— a revolutionary idea proposing doubt as a means to achieve certainty. The cogito, encapsulated by the famous dictum "Cogito, ergo sum" ("I think, therefore I am"), underscores the assertion that the act of thinking itself is the only undeniable proof of existence. This foundational belief paves the way for a new framework of knowledge, one built upon the indubitable truth of self-awareness. Complementing the philosophical underpinnings of his discourse, Descartes' essays— "La Dioptrique," "Les Météores," and "La Géométrie"—serve as practical applications of his method. In "La Dioptrique," he delves into the principles of optics, elucidating the laws of refraction and reflection through geometric analysis. This exploration not only advances the understanding of light and vision but also demonstrates the application of mathematical principles to physical phenomena, a novel approach at the time. Similarly, in "Les Météores," Descartes applies his method to the explanation of meteorological phenomena, eschewing Aristotelian explanations in favor of physical principles. This essay exemplifies his belief in the universality of physical laws and their ability to explain natural phenomena, a cornerstone of the modern scientific approach. Perhaps the most profound impact of Descartes' work is evidenced in "La Géométrie," where he introduces the Cartesian coordinate system. This innovation allows for the description of geometric figures through algebraic equations, fundamentally bridging the gap between algebra and geometry. The implications of this for the development of calculus and modern mathematics cannot be overstated, as it provided the tools necessary for the precise analysis of geometric space. The legacy of Descartes' "Discourse on the Method" and its accompanying essays extends far beyond their immediate contributions to mathematics and science. By championing reason as the primary source of knowledge and advocating for a systematic approach to inquiry, Descartes laid the groundwork for the Enlightenment and the eventual rise of the scientific method. His work symbolizes the transition from medieval to modern thought, emphasizing the power of the human mind to understand and shape the world.

The first edition of Descartes' work, published in Leiden, can be identified by the title page, which bears the imprint of Jan Maire and the date 1637.