AN EXAMINATION OF LOGICAL POSITIVISM By JULIUS RUDOLPH WEINBERG, PH. D. Cornell University LONDON KEGAN PAUL, TRENCH, TRUBNER CO., LTD. NEW YORK HARCOURT, BRACE AND COMPANY 1936 Dedicated to my Mother PRINTED IN GREAT BRITAIN BY STEPHEN AUSTIN AND SONS, LTD., HERTFORD. CONTENTS PAGE PREFACE ........ vii INTRODUCTION ....... i PART I. LOGICAL FOUNDATIONS CHAPTER I. WITTGENSTEINS THEORY OF MEANING . . 31 II. LOGIC AND MATHEMATICS .... 69 PART II. THEORY OF SCIENTIFIC METHOD 105 III. PROBABILITY ...... 107 IV. INDUCTION ...... 130 V. THE NATURE OF NATURAL LAW . 143 PART III. THE ELIMINATION OF METAPHYSICS 173 VI. ELIMINATION OF METAPHYSICS . . . 175 VTIv LINGUISTIC SOLIPSISM . . . 200 III. THE POSITIVISTIC THEORY OF KNOWLEDGE . 208 PART IV. RADICAL PHYSICALISM 227 IX. LOGICAL SYNTAX OF LANGUAGES . . 231 X. PROBLEMS OF SCIENTIFIC METHOD AND PHILOSOPHY IN TERMS OF LOGICAL SYNTAX 250 XL THE PHYSICAL LANGUAGE . . . .262 XII. CRITIQUE OF PHYSICALISM . . . 281 PART V. CONCLUSION XIII. AN ESTIMATE OF THE VIENNESE CIRCLE . . 289 XIV. THE POSSIBILITY OF AN ALTERNATIVE THEORY OF LANGUAGE 295 INDEX OF NAMES ....... 309 INDEX OF SUBJECTS ...... 311 PREFACE I wish to express my gratitude to the members of the Sage School of Philosophy, especially Professors Burtt, Sabine, and Church, for their kindness in making many helpful suggestions and criticisms. I am also indebted to Dr. Rudolf Carnap for the explanation of several difficult points of logical syntax, and because he has allowed me to read an unpublished manuscript on the subject of meaning and verification. Finally, I wish to thank Professor Henry Bittermann, of Ohio State University, for reading the manuscript, and Mr. Manley Thompson, Jr., for reading the proof and preparing the indices. J. R. W. July, 1936. AN EXAMINATION OF LOGICAL POSITIVISM INTRODUCTION I The philosophy of the Viennese Circle has undergone so many radical changes since its formal organization in 1928 that a statement of its aims is likely to include too much, or to omit too much to be very informative. Nevertheless, the first statement of its official programme is sufficiently general to avoid misunderstanding. In this official statement 1 the principal aims are set out as follows first to provide a secure foundation for the sciences, and second to demonstrate the meaninglessness of all metaphysics. The method used to realize these aims is the logical analysis of all concepts and propositions. There have been other philosophical movements devoted to similar purposes, among which nineteenth century positivism and pragmatism may be mentioned. Likewise other philosophical movements have exclusively employed logical analysis to demonstrate their doctrines. The various contemporary realistic philosophies are specific instances. The unique characteristic of the philosophy of the Viennese Circle is the exclusive use of logical analysis to demonstrate positivistic theses. The two most fundamental doctrines of Logical Positivism are i that propositions of existential import have an exclusively empirical reference, and 2 that this empirical reference can be conclusively shown by logical analysis. The empiristic doctrine is thus to be proved by a logical method. This calls for an account of logic consistent with 1 Wissenschaftliche Weltauffassung, Der Wiener Kreis, Wien, 1929, s. 158. 2 INTRODUCTION such a thorough-going empiricism. At first sight this would seem to present a difficulty. Philosophical systems which employ logical methods almost exclusively would undoubtedly be expected to produce non-empirical results. If, however, logic is taken simply as a method of connecting meanings it is not difficult to reconcile logical methods with empirical results. If logical formulae, in other words, assert nothing about the meanings of propositions, but simply show how such meanings are connected, then an empiricism based on a logical analysis of meanings is not inconsistent...