These two 1985 volumes provide a translation of the philosophical works of Descartes, based on the best available Latin and French texts. They were intended to replace the only reasonably comprehensive selection of his works in English, by Haldane and Ross, first published in 1911. General introduction viii Chronological table of Descartes' life and works xi Early Writings Translator's preface 1(1) Early Writings 2(7) Rules for the Direction of the Mind Translator's preface 7(2) Rules for the Direction of the Mind 9(72) Rule One 9(1) Rule Two 10(3) Rule Three 13(2) Rule Four 15(5) Rule Five 20(1) Rule Six 21(4) Rule Seven 25(3) Rule Eight 28(5) Rule Nine 33(1) Rule Ten 34(3) Rule Eleven 37(2) Rule Twelve 39(12) Rule Thirteen 51(5) Rule Fourteen 56(9) Rule Fifteen 65(1) Rule Sixteen 66(4) Rule Seventeen 70(1) Rule Eighteen 71(5) Rule Nineteen 76(1) Rule Twenty 76(1) Rule Twenty-one 76(1) Appendix 77(2) The World and Treatise on Man Translator's preface 79(2) The World or Treatise on Light 81(18) Treatise on Man 99(12) Discourse and Essays Translator's preface 109(2) Discourse on the Method 111(41) Part One 111(5) Part Two 116(6) Part Three 122(4) Part Four 126(5) Part Five 131(10) Part Six 141(11) Optics 152(41) Principles of Philosophy Translator's preface 177(2) Preface to French Edition 179(11) Dedicatory Letter to Elizabeth 190(3) Principles of Philosophy 193(101) Part One: The Principles of Human Knowledge 193(30) Part Two: The Principles of Material Things 223(25) Part Three: The Visible Universe 248(19) Part Four: The Earth 267(26) Comments on a Certain Broadsheet Translator's preface 293(1) Comments on a Certain Broadsheet 294(20) Description of the Human Body Translator's preface 313(1) Description of the Human Body and of all its Functions 314(14) The Passions of the Soul Translator's preface 325(1) Prefatory letters 326(2) The Passions of the Soul 328(77) Part One: The Passions in General 328(21) Part Two: The Number and Order of the Passions 349(34) Part Three: Specific Passions 383(22) Index 405