Descartes theory of light and refraction

Historical Significance: Rene Descartes (1596 - 1650) was a French philosopher, mathematician, and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day. In particular, his Meditations on First Philosophy continues to be a standard text; his influence in mathematics is equally apparent; the Cartesian co-ordinate system was named after him. He is credited as the father of analytical geometry crucial to the discovery of infinitesimal calculus and analysis. Descartes was a major figure in 17th-century continental rationalism, later advocated by Baruch Spinoza and Gottfried Leibniz, and opposed by the empiricist school of thought consisting of Hobbes, Locke, Berkeley, Jean-Jacques Rousseau, and Hume. Leibniz, Spinoza and Descartes were all well versed in mathematics as well as philosophy, and Descartes and Leibniz contributed greatly to science as well. He is perhaps best known for the philosophical statement "Cogito ergo sum" (French: Je pense, donc je suis; English: I think, therefore I am), found in part IV of Discourse on the Method. This book critically discusses Descartes contributions to the discovery of the law of refraction (Snell's law) that was finally enunciated in 1621. The author of this monograph, Mark Smith was Associate Professor of History at the University of Missouri at time this book was published and later professor at the same university. He has published other books on early history of optics and vision including Ptolemy and the Foundations of Ancient Mathematical Optics: A Source-Based Guided Study. Philadelphia: American Philosophical Society, 1999 and Alhacen's Theory of Visual Perception. Philadelphia: American Philosophical Society, 2001.