Rhonda Martens is Assistant Professor of Philosophy at the University of Manitoba.

• Figures and Tables ix Acknowledgments xi Abbreviations of Works Frequently Cited xiii Introduction 3 1. Kepler's Life and Times 10 Select Biography 10 Kepler's Astronomical Inheritance 18 Kepler's Philosopbical Inheritance 32 2. The Mysterium cosmographicum and Kepler's Early Approach to Natural Philosophy 39 The Content of the Mysterium cosmographicum 39 Kepler's Cosmology 48 Kepler's Approach to Natural Philosophy 49 3. Kepler's Apologia: An Early Modern Treatise on Realism 57 Extra-Astronomical Considerations 58 The Nature of Astronomical Hypotheses 60 The Testing of Astronomucal Hypotheses 63 Kepler's Improved Notion of Testability 64 Concluding Remarks: The Archetypes 67 4. Kepler's Archetypes and the Astronomia nova 69 The Status of Hypotheses in Physical Astronomy 70 The Replacement of the Mean by the True Sun 71 The Vicarious Hypothesis 76 The New Physics 79 Kepler's Second Law 84 Oval Orbits 87 Physical and Geometrical Models of Liberation 91 The Ellipse of Chapter 59 95 Concluding Remarks: Archetypes in the Astronomia 97 5. The Aristotelian Kepler 99 The Aristotelian Challenge 9O Physical Astronomy as a Mixed Discipline 103 The Mathematical and the Physical 106 Concluding Remarks 111 6. The Harmonice mundi 112 Kepler and Ptolemy 112 The Essence of Archetypal Mathematics 118 Synopsis of Book V 120 The Influence of Kepler's Haramonies on His Cosmology 136 7. The Epitome astronomiae Copernicanae: Kepler's Mature Physical Astronomy 142 The Nature of Astronomy and Observation 144 Archetypes as a Prerequisite for Physics 146 Book IV and the Archetypes 147 Book V 163 Concluding Remarks 167 Conclusion: The Fate of Kepler's Philosophical Thought 169 The Threat to the Perfectibility of Astronomy 169 Kepler's Philosophical Legacy 172 Notes 177 Bibliography 191 Index 199

"Rhonda Martens shows in this historically informed tome that Kepler grappled constantly, and advantageously with philosophical problems throughout his career... The truly original contribution of [this book] is the tracing of Kepler's philosophical ideas as they weave through and strengthen his science."--Bruce Stephenson, Astronomy "This little book makes a big contribution not only to Kepler studies but to our understanding of early modern philosophy in general... Martens has effectively shown that to understand Kepler, to understand how he influenced his times, and to understand how his times grappled with the issues he and other innovators were dealing with, it is necessary to look closely at his philosophy."--Sheila J. Rabin, Isis "A valuable contribution to our understanding of Kepler... More broadly, Kepler's Philosophy increases our understanding of the significant role that philosophical questions played in the scientific debates of the sixteenth and seventeenth centuries."--Kathryn Morris, Philosophy in Review

Rhonda Martens is Assistant Professor of Philosophy at the University of Manitoba.

• Figures and Tables ix Acknowledgments xi Abbreviations of Works Frequently Cited xiii Introduction 3 1. Kepler's Life and Times 10 Select Biography 10 Kepler's Astronomical Inheritance 18 Kepler's Philosopbical Inheritance 32 2. The Mysterium cosmographicum and Kepler's Early Approach to Natural Philosophy 39 The Content of the Mysterium cosmographicum 39 Kepler's Cosmology 48 Kepler's Approach to Natural Philosophy 49 3. Kepler's Apologia: An Early Modern Treatise on Realism 57 Extra-Astronomical Considerations 58 The Nature of Astronomical Hypotheses 60 The Testing of Astronomucal Hypotheses 63 Kepler's Improved Notion of Testability 64 Concluding Remarks: The Archetypes 67 4. Kepler's Archetypes and the Astronomia nova 69 The Status of Hypotheses in Physical Astronomy 70 The Replacement of the Mean by the True Sun 71 The Vicarious Hypothesis 76 The New Physics 79 Kepler's Second Law 84 Oval Orbits 87 Physical and Geometrical Models of Liberation 91 The Ellipse of Chapter 59 95 Concluding Remarks: Archetypes in the Astronomia 97 5. The Aristotelian Kepler 99 The Aristotelian Challenge 9O Physical Astronomy as a Mixed Discipline 103 The Mathematical and the Physical 106 Concluding Remarks 111 6. The Harmonice mundi 112 Kepler and Ptolemy 112 The Essence of Archetypal Mathematics 118 Synopsis of Book V 120 The Influence of Kepler's Haramonies on His Cosmology 136 7. The Epitome astronomiae Copernicanae: Kepler's Mature Physical Astronomy 142 The Nature of Astronomy and Observation 144 Archetypes as a Prerequisite for Physics 146 Book IV and the Archetypes 147 Book V 163 Concluding Remarks 167 Conclusion: The Fate of Kepler's Philosophical Thought 169 The Threat to the Perfectibility of Astronomy 169 Kepler's Philosophical Legacy 172 Notes 177 Bibliography 191 Index 199

"Rhonda Martens shows in this historically informed tome that Kepler grappled constantly, and advantageously with philosophical problems throughout his career... The truly original contribution of [this book] is the tracing of Kepler's philosophical ideas as they weave through and strengthen his science."--Bruce Stephenson, Astronomy "This little book makes a big contribution not only to Kepler studies but to our understanding of early modern philosophy in general... Martens has effectively shown that to understand Kepler, to understand how he influenced his times, and to understand how his times grappled with the issues he and other innovators were dealing with, it is necessary to look closely at his philosophy."--Sheila J. Rabin, Isis "A valuable contribution to our understanding of Kepler... More broadly, Kepler's Philosophy increases our understanding of the significant role that philosophical questions played in the scientific debates of the sixteenth and seventeenth centuries."--Kathryn Morris, Philosophy in Review

Rhonda Martens is Assistant Professor of Philosophy at the University of Manitoba.

• Figures and Tables ix Acknowledgments xi Abbreviations of Works Frequently Cited xiii Introduction 3 1. Kepler's Life and Times 10 Select Biography 10 Kepler's Astronomical Inheritance 18 Kepler's Philosopbical Inheritance 32 2. The Mysterium cosmographicum and Kepler's Early Approach to Natural Philosophy 39 The Content of the Mysterium cosmographicum 39 Kepler's Cosmology 48 Kepler's Approach to Natural Philosophy 49 3. Kepler's Apologia: An Early Modern Treatise on Realism 57 Extra-Astronomical Considerations 58 The Nature of Astronomical Hypotheses 60 The Testing of Astronomucal Hypotheses 63 Kepler's Improved Notion of Testability 64 Concluding Remarks: The Archetypes 67 4. Kepler's Archetypes and the Astronomia nova 69 The Status of Hypotheses in Physical Astronomy 70 The Replacement of the Mean by the True Sun 71 The Vicarious Hypothesis 76 The New Physics 79 Kepler's Second Law 84 Oval Orbits 87 Physical and Geometrical Models of Liberation 91 The Ellipse of Chapter 59 95 Concluding Remarks: Archetypes in the Astronomia 97 5. The Aristotelian Kepler 99 The Aristotelian Challenge 9O Physical Astronomy as a Mixed Discipline 103 The Mathematical and the Physical 106 Concluding Remarks 111 6. The Harmonice mundi 112 Kepler and Ptolemy 112 The Essence of Archetypal Mathematics 118 Synopsis of Book V 120 The Influence of Kepler's Haramonies on His Cosmology 136 7. The Epitome astronomiae Copernicanae: Kepler's Mature Physical Astronomy 142 The Nature of Astronomy and Observation 144 Archetypes as a Prerequisite for Physics 146 Book IV and the Archetypes 147 Book V 163 Concluding Remarks 167 Conclusion: The Fate of Kepler's Philosophical Thought 169 The Threat to the Perfectibility of Astronomy 169 Kepler's Philosophical Legacy 172 Notes 177 Bibliography 191 Index 199

"Rhonda Martens shows in this historically informed tome that Kepler grappled constantly, and advantageously with philosophical problems throughout his career... The truly original contribution of [this book] is the tracing of Kepler's philosophical ideas as they weave through and strengthen his science."--Bruce Stephenson, Astronomy "This little book makes a big contribution not only to Kepler studies but to our understanding of early modern philosophy in general... Martens has effectively shown that to understand Kepler, to understand how he influenced his times, and to understand how his times grappled with the issues he and other innovators were dealing with, it is necessary to look closely at his philosophy."--Sheila J. Rabin, Isis "A valuable contribution to our understanding of Kepler... More broadly, Kepler's Philosophy increases our understanding of the significant role that philosophical questions played in the scientific debates of the sixteenth and seventeenth centuries."--Kathryn Morris, Philosophy in Review