René Descartes, 1596-1650
Noted French philosopher, mathematician, and scientist. Dubbed the "Founder of Modern Philosophy" and the "Father of Modern Mathematics," he ranks as one of the most important and influential thinkers of modern times. For good or ill, much of subsequent western philosophy is a reaction to his writings, which have been closely studied from his time down to the present day.
Descartes founded 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 & Hume. Leibniz, Spinoza and Descartes were all versed in mathematics as well as philosophy, and Descartes and Leibniz contributed significantly to science as well. As the inventor of the Cartesian coordinate system, Descartes founded analytic geometry, that bridge between algebra and geometry crucial to the invention of the calculus and analysis.
- Compendium Musica 
- Rules for the Direction of the Mind 
- Discourse on the Method of Rightly Conducting the Reason, and Seeking the Truth in the Sciences 
- La Géométrie 
- Meditations on First Philosophy 
- Les Principes de la philosophie (Principles of Philosophy) 
- The Singing Epitaph 
- Comments on a Certain Broadsheet 
- The Description of the Human Body 
- Conversation with Burman 
- Passions of the Soul