The course of the discussion in this part of the work will be best shown by enumerating the titles to the chapters, which are as follows: I. Laws in General; II. The Law of Evolution; III. The Same continued; IV. The Causes of Evolution; V. Space, Time, Matter, Motion, and Force; VI. The Indestructibility of Matter; VII. The Continuity of Motion; VIII. The Persistence of Force; IX. The Correlation and Equivalence of Forces; X. The Direction of Motion; XI. The Rhythm of Motion; XII. The Conditions Essential to Evolution; XIII. The Instability of the Homogeneous; XIV. The Multiplication of Effects; XV. Differentiation and Integration; XVI. Equilibration; XVII. Summary and Conclusion.
A most interesting and fruitful field of thought, it will be seen, is here traversed 7by our author, and the latest and highest questions of science are discussed under novel aspects and in new relations. Not only do the pages abound with acute suggestions and fresh views, but the entire argument, in its leading demonstrations, and the full breadth of its philosophic scope, is stamped with a high originality.
Having thus determined the sphere of philosophy and ascertained those fundamental principles governing all orders of phenomena which are to be subsequently used for guidance and verification, the author proceeds to the second work of the series, which is devoted to Biology, or the Science of Life. He regards life not as a foreign and unintelligible something, thrust into the scheme of nature, of which we can know nothing save its mystery, but as an essential part of the universal plan. The harmonies of life are regarded as but phases of the universal harmony, and Biology is studied by the same methods as other departments of science. The great truths of Physics and Chemistry are applied to its elucidation; its facts are collected, its inductions established, and constantly verified by the first principles laid down at the outset. Apart from its connections with the philosophical system, of which it forms a part, this work will have great intrinsic interest. Nothing was more needed than a compact and well-digested statement of those general principles of life to which science has arrived, and Mr. Spencer's presentation is proving to be just what is required. Some idea of his mode of treating the subject may be formed by glancing over a few of his first chapter-headings. Part First: I. Organic Matter; II. The Actions of Forces on Organic Matter; III. The Reactions of Organic Matter on Forces; IV. Proximate Definition of Life; V. The Correspondence between Life and its Circumstances; VI. The Degree of Life Varies with the Degree of Correspondence; VII. Inductions of Biology. Part Second: I. Growth; II. Development; III. Function; IV. Waste and Repair; V. Adaptation; VI. Individuality; VII. Genesis; VIII. Heredity; IX. Variation; X. Genesis, Heredity and Variation; XI. Classification; XII. Distribution.
In the scheme of nature Mind is ever associated with Life. The third division of this philosophical system will therefore be Psychology, or the Science of Mind. This great subject will be considered, not by the narrow methods usual with metaphysicians, but in its broadest aspects as a phase of nature's order—to be studied by observation and induction through the whole range of psychical manifestation in animated beings. The subject of mind will be regarded in the light of the great truths of Biology previously established; the connections of mind and life will be traced; the progress of mentality as exhibited in the animal grades, and the evolution of the intellectual faculties in man will be delineated and the coöperation of mind and nature in the production of ideas and intelligence unfolded. We have no work upon mind of this comprehensive and thoroughly scientific character: the materials are abundant, and the necessity of their organization is widely recognized. That Mr. Spencer is eminently the man to perform this great task is proved by the fact that he is already the author of the most profound and able contribution to the advancement of psychological science that has appeared for many years.
In the true philosophic order, Biology and Psychology prepare the way for the study of social science, and hence the fourth part of Mr. Spencer's system will treat of Sociology, or the natural laws of society. As a knowledge of individuals must precede an understanding of their mutual relations, so an exposition of the laws of life and mind, which constitute the science of human nature, must precede the successful study of social phenomena. In this part will be considered the development of society, or that intellectual and moral progress which depends upon the growth of human ideas and feelings in their necessary order. The evolution of political, ecclesiastical, and industrial organizations will be traced, and a statement made of those principles underlying all social progress, without which there can be no successful regulation of the affairs of society. Mr. Spencer's mind has long been occupied with these important questions, as the reader will find by referring to his able work upon "Social Statics," published several years ago.