ence Causes, Historical Causation, Catastrophe and Uniformity, First Cause. The controversies to which the exact fixation of these Ideas and their properties have given occasion form a large and essential part of the History of Science: but they also form an important part of the Philosophy of Science, for no Philosophy of Sci can be complete which does not solve the difficulties, antitheses, and paradoxes on which such controversies have turned. I have given a survey of such controversies, generally carried from their earliest origin to their latest aspect; and have stated what appeared to me the best solution of each problem. This has necessarily involved me in much thorny metaphysics; but such metaphysics is a necessary part of the progress of Science. The human mind deriving its knowledge of Truth from the observation of nature, cannot evade the task of determining at every step how Truth is consistent with itself. This is the Metaphysics of Progressive Knowledge, and this is the matter of this present History. Of the remaining part of what was formerly published as the Philosophy of the Inductive Sciences, an additional part, described in the Introduction to the present work, will shortly be published. TRINITY LODGE, May 24, 1858. ERRATUM. P. 157, 1. us from top, for sciences read science. Successive Generalization 43 49 II. PAGE CHAP. III. OF NECESSARY TRUTHS The two Elements of Knowledge, 3. Examples of necessary Truths in numbers. CHAP. V. OF THE GROUNDS OF NECESSARY TRUTHS These Grounds are Fundamental Ideas. 6. Axioms needed. Art. 1. No connexion observed. Faculties implied in observation. 2. 1 Art. 1. Geometry, Arithmetic, Algebra, 5. Space, Time, Number. CHAP. II. OF THE IDEA OF SPACE 2. Not derived from Experience, 3. As Geometrical Truth shows. 5. The phrase not essential. CHAP. III. OF SOME PECULIARITIES OF THE IDEA OF Art. 1. Space is not an Abstract Notion. a CHAP. IV. OF THE DEFINITIONS AND AXIOMS WHICH CHAP. V. OF SOME OBJECTIONS WHICH HAVE BEEN MADE TO THE DOCTRINES STATED IN THE PREVIOUS How is Geometry hypothetical ? Art. 1. 2. PAGE 3. 'Legitimate filiations' of Definitions. 4. Is a Definition a complete explanation ? 5. Are some Axioms Definitions ? CHAP. VI. OF THE PERCEPTION OF SPACE · 117 2. Perception of solid figure. 7. Do we perceive Space by Touch? 11. Perception includes Activity. 12. Perception of the Skyey Dome. 17. Expressions implying Motion. CHAP. VII. OF THE IDEA OF TIME . Time an Idea not derived from Experience. 4. Is Timne derived from Motion ? 134 Time is infinite. 3. Time is a Form of Intuition. 8. Arithmetic. 2. |