First philosophy 6 Philosophy 6 Methodology 5 Knowledge, Theory of 4 Metaphysics 4 Descartes, Rene-Philosophy 3 Science 3 Descartes, Rene-Criticism and interpretation 2 God 2 God-Proof, Ontological 2 Meditations 2 Philosophy, French 2 Applied Psychology 1 Biography 1 Collections. [from old catalog] 1 Dioptrics 1 Early works to 1800 1 First Philosophy 1 France 1 Geometry 1 Geometry, Analytic 1 Individual philosophers-- 1 Mataphysics 1 Mathematicians 1 Optics Early Works 1 Philosopher 1 Philosophy Auguste Comte 1 Philosophy Charles Darwin 1 Philosophy Descartes 1 Philosophy France 1