KURT SMITH is a Professor of Philosophy at Bloomsburg University of Pennsylvania, USA. He has participated in three competitive National Endowment for the Humanities summer programs focused on Early Modern Philosophy and has been a Visiting Scholar at Princeton University. Professor Smith is the author of several monographs, book chapters, journal articles, and encyclopedia entries.

Acknowledgements vii

Introduction 1

I.1 Knowledge as Scientia 2

I.2 Ideas, Propositions, and Beliefs 5

I.3 The idea of a Modern Philosophy Course 11

I.4 Rationalism and Empiricism 12

I.5 Some Other "isms" of the Period 14

I.6 The Problem of the External World 16

1 René Descartes 21

1.1 Descartes's First Principle 21

1.2 Preliminaries on Ideas and the Ontology 39

1.3 Clarity and Distinctness: A Model Based on Simple Natures 51

1.4 The Idea of the Infinite Being: A Proof for God's existence 57

1.5 Why God, Creator of Descartes's Mind, Cannot be Understood as Being a Deceiver 64

1.6 The Problem of the External World Continued: The Case for a Material World 68

Reference 74

2 Thomas Hobbes 75

2.1 Hobbes's Materialism 75

2.2 Hobbes's View of Mind 77

2.3 Concept-Pairs 83

2.4 A Body Cannot be the Origin of Its Own Motion 88

2.5 A Proof for the Existence of an External World 90

Reference 91

3 George Berkeley 92

3.1 Berkeley's Rejection of a Material World 92

3.2 Abstraction versus Exclusion 94

3.3 Objects are Collections of Ideas 101

3.4 The Problem of the External World Answered: The Omni-perceiver 134

3.5 Possible Common Ground 143

4 David Hume 147

4.1 Hume on Impressions and Ideas 148

4.2 The Idea of Cause and Effect 152

4.3 Object and Existence 156

4.4 Unity and Identity 159

4.5 Constancy, Coherence, Continued Existence, and Distinct Existence 161

5 Immanuel Kant 167

5.1 Kant's Critical Period 167

5.2 Knowledge: Preliminaries 169

5.3 Transcendental Philosophy 171

5.4 Two Distinctions and the Category of Synthetic a priori Propositions 175

5.5 The External World 192

References 202

6 Lady Mary Shepherd 203

6.1 Cause and Effect, and a Proof of the External World 203

6.2 Hume and The Problem of the External World 205

6.3 Consciousness and Sensation 206

6.4 A Commonsense Reading 227

References 230

Epilogue 232

Index 239