It was as a result of having known Juhos personally over many years that I became familiar with his thought. I met him and Viktor Kraft in Vienna soon after the War and through their acquaintance I first came into contact with the tradition of the Vienna Circle. To their conversation .too lowe much as regards the clarification of my own views, even if in the end these took quite a different turn in many essentials. At this point my gratitude goes first of all to Mrs. Lia J uhos for the gen erous help she has given me and the editors of the Vienna Circle collection in selecting the contents of this volume. Next, we owe a special debt to Dr. Paul Foulkes for his splendid translation of the text. Finally, I wish to thank Dr. Veit Pittioni for his constant assistance. As Juhos' last student, he was thoro).lghly familiar with his supervisor's mode of thought and has significantly furthered the assembly and execution of this book.

Inhalt
I. Orders of Causality.- II. Causality Commentson the Physicalist Theory of Science.- 1. Verification and Elucidation.- 2. Elimination of Metaphysical Formulations by Means of the Physical Language.- 3. The 'Privileged Position' of Protocol Propositions and the Physicalist Criterion of Probation.- 4. Obtaining the Protocol Propositions.- 5. The 'True' Science.- III. Empiricism and Physicalism.- IV. Forms of Negation of Empirical Propositions.- 1. Forms of Negation.- 2. 'Complete' and 'Incomplete' Contradictions.- 3. The Obtaining and Verifying of Propositions.- 4. Negation of Constatations.- 5. Incompatibility of 'Protocol Statements'.- Postscript.- V. Principles of Logical Empiricism.- 1. Reality Concepts, Metaphysical and Empirical.- 2. Invariant Systems of Statements.- 3. Non-Behaviouristic Verification.- 4. K-Statements and Invariant Systems of Statements.- VI. The Method of Epistemological Analysis.- 1. Analysis of Form and of Content.- 2. Formal Analysis of the Concept of Existence.- 3. Content Analysis of the Concept of Causality.- VII. Probability Inferences as Syntactic Inferential Forms.- 1. Relations of Consequence, Deductive and Probable.- 2. The System of Relations of Probable Consequence.- 3. 'Probable Consequence' and 'Logical Truth'.- VIII. 'Positive' and 'Negative' Use of Statements.- 1. Truth Value and Content.- 2. Conditions to be Satisfied by any Definition of Truth.- 3. 'Positive' and 'Negative' Use of Statements.- 4. Negation and Falsity.- 5. Confusion of Positive with Negative Use.- 6. The Recursive Definition of the Concept of Truth.- IX. The New Form of Empirical Knowledge.- 1. The 'Empirical Continuous' Form of Knowledge of Classical Physics.- 2. Uncertainty Domains as Prerequisite for theEmpirical-Fictitious Form of Knowledge.- 3. Probability Description, a Special Case of the Empirical Fictitious Form of Knowledge.- 4. Probability Functions as Relations between Measured and Fictitious Values.- 5. The Empirical Fictitious Method Conditioned by Measuring Procedures.- 6. The Definition of Probability Functions by Repeated Application of the Empirical-Fictitious Method.- X. The Methological Symmetry of Verification and Falsification.- 1. Like Names for Unlike Concepts.- 2. Empirical Propositions about Finitely and Infinitely.- Many Cases.- 3. Wittgenstein's Verification Thesis.- 4. Propositions about Finitely and Infinitely Many Cases. The Methodologies of Wittgenstein, Carnap, and Popper.- 5. 'Asymmetrical' Falsification Theories.- 6. Criteria of Scientific Progress.- 7. 'Complete' and 'Progressive Partial' Testability.- XI. Three Sources of Knowledge.- 1. The Triadic Method.- 2. Data of ConsciousnesLogico-Mathematical Constructions Methods of Empirical Content.- 3. Three concepts of 'Truth' and 'Probability'.- XII. The Triadic Method.- 1. Elements of Linguistic Representation and the Triadic Method.- 2. The Triadic Analysis of 'Truth'.- 3. The Triadic Analysis of 'Probability'.- 4. The Triadic Analysis of 'Number'.- 5. The Triadic Analysis of 'Philosophic Expressions'.- XIII. The Method of Fictitious Predicates.- 1. Scientific and Speculative Philosophy.- 2. 'Operative' and 'Fictitious' Existence.- I: Predicates as Descriptive Concept-Forms.- 1. The Existence of Logico-Linguistic Forms.- 2. Dispositional Concepts as Fictitious Predicates.- 3. Characterization of Phenomena by Fictitious Quantities.- II: Predicates as Quantities Characterizing States.- 4. Characterizing by Infinite Values ofQuantities.- 5. Characterizing Phenomena in Uncertainly Ranges by Means of Fictitious Values ('Values of Measurement').- 6. Logical Analysis of the Concepts 'Motion' and 'Rest'.- 7. Logical Analysis of the Relativity Principle.- 8. The Clock Paradox.- 9. Conditions, under which the Relativity Principle Does not Hold.- 10. Domains of Uncertainty as a Presupposition for Applying the New Method.- III: Predicates as Probability Quantities.- 11. Analytic-Deductive Inferences. Inferences from Conjunctive Classes of Propositions.- 12. Inferences from Disjunctive Classes of Propositions. Probability Inferences.- 13. Systems of Probability Metric and Their Order.- 14. The Characterization of States by Conjunctive and Disjunctive Classes of Propositions.- 15. Presuppositions of Measurement in Classical and Relativistic Physics.- 16. Description by Ranges of Quantities.- 17. Definition of Probability Quantities by Means of Functions.- 18. Descriptions by Means of Probability and Metrical Quantities.- 19. Uncertainty Domains as Prerequisite for the Method of Fictitious Predicates.- 20. The Definition of Probability Functions by Means of Operators.- 21. Empirical and Fictitious Existence of Predicates.- 22. Theories of Measurement as a Presupposition of Exact-Continuous and of Probability Description.- 23. The Epistemological Conditions for Applying the Method of Fictitious Predicates.- 24. The Probability Field.- 25. Probability Description and Indeterminacy of Phenomena.- 26. The Logical Meaning of Quantisation. First and Second Quantisation.- 27. The Quantisation of Electromagnetic Fields.- IV. Empirical-Fictitious Knowledge.- 28. Active and Fictitious Causality.- 29. Greatest Possible and Least Possible Physical Constants.- 30. The New Form of Knowledge.- 31. TheMatrix Field and the Probability Wave Field.- 32. Probability Description in Biology.- Index of Names.