I. INTRODUCTION PART ONE: PERCEPTION 2. AN ANALYSIS OF PERCEPTION 3· THE PHILOSOPHICAL THEORIES OF PERCEPTION 4· PHENOMENALISM 5· THE ARGUMENTS TO SENSE-DEPENDENCE 6. THE ARGUMENT FROM ILLUSION 7• THE ARGUMENTS FROM SCIENCE 8. THE DEFENCE OF REALISM 9· THE CHOICE BETWEEN THE THEORIES PART TWO: OUR KNOWLEDGE OF THE EXTERNAL WORLD 10. PERCEPTION AND KNOWLEDGE 11. SENSE DATA 12. OUR KNOWLEDGE OF EXTERNAL EXISTENCE LIST OF WORKS CITED INDEX.