XXIX. Origin and Character of the relation between Language and Ideas 112 XXX. Innate Ideas 115 BOOK FIFTH. IDEA OF BEING. I. Idea of Being 125 II. Simplicity and Indeterminateness of the Idea of Being 127 III. Substantive and Copulative Being 129 IV. Being, the Object of the Understanding, is not the Possible, Inasmuch as Possible 134 V. A Difficulty Solved 138 VI. In what Sense the Idea of Being is the Form of the Understanding 141 VII. All Science is founded in the Postulate of Existence 143 VIII. The foundation of Pure Possibility, and the Condition of its Existence 147 IX. Idea of Negation 150 X. Identity; Distinction; Unity; Multiplicity 153 XI. Origin of the Idea of Being 155 XII. Distinction between Essence and Existence 161 XIII. Kant's Opinion of Reality and Negation 164 XIV. Recapitulation and Consequences of the Doctrine concerning the Idea of Being 168 BOOK SIXTH. UNITY AND NUMBER. I. Preliminary Considerations on the Idea of Unity 175 II. What is Unity? 176 III. Unity and Simplicity 180 IV. Origin of the Tendency of our Mind to Unity 183 V. Generation of the Idea of Number 187 VI. Connection of the Ideas of Number with their Signs 191 VII. Analysis of the Idea of Number in Itself and its Relations with Signs 194 BOOK SEVENTH. ON TIME. I. Importance and Difficulty of the Subject 201 II. Is Time the Measure of Movement? 203 III. Similarities and Differences between Time and Space 206 IV. Definition of Time 211 V. Time is Nothing Absolute 213 VI. Difficulties in the explanation of Velocity 215 VII. Fundamental Explanation of Succession 219 VIII. What is Co-existence? 223 IX. Present, Past, and Future 226 X. Application of the preceding Doctrine to several important Questions 231 XI. The Analysis of the Idea of Time confirms its resemblance to the Idea of Space 234 XII. Relations of the Idea of Time to Experience 236 XIII. Kant's Opinion 239 XIV. Fundamental Explanation of the Objective Possibility and of the Necessity of the Idea of Time 242