Karl Popper described Die Beiden Grundrpobleme der Erkenntnistheorie - The Two Fundamental Problems of Knowledge - as " above all about... the crisis of physics. It asserts the permanence of crisis; if it is right, then crisis is the normal state of a highly developed rational science." Finally available in English for the first time, it is a major contribution to Twentieth century philosophy.

Preface 1978 Introduction 1978 Exposition [1933] Book I: The Problem of Induction (Experience and Hypothesis) The Two Fundamental Problems of the Theory of Knowledge Volume I 1. Formulation of the Problem 2. Deductivism and Inductivism 3. The Problem of Induction 4. The Normal-Statement Positions 5. Kant and Fries 6. The Probability Positions 7. The Pseudo-Statement Positions 8. Conventionalism 9. Strictly Universal Statements and Singular Statements 10. Back to the Pseudo-Statement Positions 11. Pseudo-Statement Positions and the Concept of Meaning 12. Conclusion Appendix: The Critique of the Problem of Induction in Schematic Representation Book II: The Problem of Demarcation (Experience and Metaphysics) The Two Fundamental Problems of the Theory of Knowledge Volume II (Fragments) Part 1: Fragments 1932 1. Sketch of an Introduction 2. Formulation of the Problem 3. On the Question of Eliminating Subjectivist Psychologism 4. Transition to the Theory of Method 5. The Method of Exhaustion. -- "State of Affairs" and "Fact". -- Universal Diversity 6. Sketch of a Theory of Empirical-Scientific Methods (Theory of Experience) Part 2: Fragments 1933 7. Orientation 8. Philosophy 9. The Problem of Methodology 10. Comments on the So-Called Problem of Free Will 11. The Problem of Free Will 12. The Problem of the Randomness in Probability Statements Appendix: Summary Excerpt (1932) from The Two Fundamental Problems of the Theory of Knowledge. Editor's Postscript. Index of Names. Index of Subjects.