devoted to that most widespread metaphysics of our own day which calls itself by the name of science, and brings forward its dogmas under the shelter of columns of figures and records of observations. The conception of scientific experience is profoundly modified by Professor Riehl's theory of the immediate perception of the external world; and the question as to the relation of psychical phenomena and physical processes receives a clear answer in harmony with the positions of the Kantian philosophy. Finally, I should like to call attention to the distinct recognition of the social factors in experience, e.g., in Part I., chapter iii.; Part II., chapters i. and iii. The principles of logic and of ethics have a social existence and sphere of activity, which has been obscured by the tendency among philosophers to regard each mind as an independent unit or monad. Individual personality is a social product, and the attempt to explain thought and action without reference to society is essentially absurd. With reference to the translation itself only a word is necessary. I have ordinarily translated the word Vorstellung by idea, although not infrequently some other word was necessary to bring out the sense clearly; I have written Idea when the German word was Idee, except in some cases where it seemed fair to translate this word by ideal. It goes without saying that I have not attempted to reproduce the German literally, but I hope the meaning has been rendered with accuracy. Much of the translation has been read by Professor Riehl, and parts of it by other friends; the author has made numerous minor changes and corrections which will be incorporated in the second German edition. NEW HAVEN, CONNECTICUT, U.S. A., April 1894. ARTHUR FAIRBANKS. AUTHOR'S PREFACE TO THE ENGLISH TRANSLATION THE German original of this work, appearing in 1887, formed the conclusion of a larger work, "Philosophical Criticism, and its Meaning for Positive Science." Still, the following investigations as to the general theory of science, and metaphysics, have a considerable degree of independence, both as to the subjects treated, and the form of treatment. The first division of the book discusses problems of the general theory of science: questions as to the true idea of philosophy, and the distinction between metaphysical and scientific system-making, as to the limits of knowledge which are found to be its presuppositions, and as to the origin and conception of experience. The second part treats those metaphysical problems which the critical method can grasp and handle scientifically. The author includes under this heading the questions as to the reality of the external world, the connection of psychical phenomena with material processes, the problem of the freedom of the will, the cosmological problem of the infinite, in so far as this stands in connection with the principle of the indestructibility of matter, the persistence of force, and the fundamental idea of causality, and finally the discussion of the relation of necessity and adaptation in nature, of the mechanical and the teleological conception of things. The separation of the book into two parts should not destroy the inner connection of the thoughts. Although this arrangement of the material may have necessitated some repetition, still it had the advantage of giving greater freedom to the discussion than would have been possible if the topics had been arranged according to an exact system. The reader will recognise that chapters i. and iv. of the first part stand in close connection, as also chapter ii. of the first part, and chapters ii. and v. of the second part. In treating the question of the determinism of the will and practical freedom, it proved impossible to avoid some questions of practical philosophy. In antithesis to ordinarily received opinion, it was necessary to show that determinism alone explains moral responsibility and justifies it. With reference to the history of the idea of responsibility (p. 246), it may be added that in primitive states of society, it is not the doer at all, but rather his clan, which is held responsible for an act. May the book in this form also contribute something to the understanding of these scientific problems, as well as to the distinctly practical task of philosophy. A. RIEHL. FREIBURG i. B., April 1894. CONTENTS § 1. The twofold conception of philosophy in antiquity-Philosophy as the science of the Greeks. § 2. The Greek form of science supplanted by the modern form in the seventeenth century— Idea of philosophy held by Galileo, Hobbes, Descartes, and Leibnitz-Separation of philosophy and science in the period after Kant. § 3. Theoretical philosophy is not a systematic theory of the world-The scientific elements of the theory of the world are furnished by positive investigation. § 4. Philo- sophy as science and as critique of knowledge. § 5. Relation to logic; distinction from the study of the development of consciousness. § 6. The practical conception of philosophy. § 7. The root of the practical and of the theoretical view of logy. §3. Criticism of the proposition that we do not know the essence of things-Relativity of the concept essence— The 66 essence "of things is made by the mind, and so must be completely knowable. § 4. The distinction between things themselves and phenomena cannot be understood as a difference of value-Thing-in-itself and noumenon. § 5. The facts of experience are psycho-physical phenomena-The correlation of subject and object. § 6. The question: How do sensations arise from motions of atoms? is falsely stated; its true state- ment is at the same time its solution. § 7. Physical laws as laws of sensations-Real and possible phenomena for external § 8. Motion is not the cause of the character of a sensation-Relativity of the ideas of extension, impenetra- bility, and motion - The scientific idea of the external world. § 9. The theory of descent and development cannot explain the qualities in sensation-Meaning of sensation for the theory of knowledge. § 10. Sensation and consciousness- Impossibility of explaining consciousness-Law in the external world, and the unity of consciousness-Relation of the unity of consciousness to the principle of the persistence of matter PAGE § 1. Empiricism and nativism—Mechanical origin of the activity of sense- —Physiological nativism may take the place of psycho- logical. § 2. Empiricism and nativism in philosophy. § 3. The theory of unconscious inferences: Schopenhauer and Helm- holtz-Projection of sensations-Retina images not real but virtual images-Vision without retina images-Distinction between real and perceived space-Projection into “real” space a conscious act. § 4. The perception of the external world immediate and original. § 5. Perception and ex- perience. § 6. Origin of the universal validity of perception -Experience as a social conception-Psychological and logical categories. § 7. Cause and reason, thing and substance as examples. § 8. The à priori element in experience. § 9. Re- duction of the logical categories to the analytical, synthetical, and analytical-synthetical unifying function of consciousness. |