Hans Vaihinger (1852–1933) was born near Tübingen in Germany. He made important contributions to epistemology, the philosophy of science and mathematics, and to the historiography of philosophy. Vaihinger produced groundbreaking work on Kant’s philosophy, as well as one of the first serious philosophical commentaries on Nietzsche. He is best known as the father of the philosophical theory of fictionalism, which he sets out in his most famous book, The Philosophy of ‘As If’, and his work also influenced the philosophical movement of pragmatism.

• Foreword to the Routledge Classics Edition Michael Rosenthal General Introduction Part 1: Basic Principles General Introductory Remarks on Fictional Constructs A. The Enumeration and Division of Scientific Fictions B. The Logical Theory of Scientific Fictions C. Contributions to the History and Theory of Fictions D. Consequences for the Theory of Knowledge Part 2: Amplified Study of Special Problems 1. Artificial Classification 2. Further Artificial Classifications 3. Adam Smith's Method in Political Economy 4. Bentham's Method in Political Science 5. Abstractive Fictional Methods in Physics and Psychology 6. Condillac's Imaginary Statue 7. Lotze's 'Hypothetical Animal' 8. Other Examples of Fictitious Isolation 9. The Fiction of Force 10. Matter and Materialism as Mental Accessories 11. Abstract Concepts as Fictions 12. General Ideas as Fictions 13. Summational, Nominal, and Substitutive Fictions 14. Natural Forces and Natural Laws as Fictions 15. Schematic Fictions 16. Illustrative Fictions 17. The Atomic Theory as a Fiction 18. Fictions in Mathematical Physics 19. The Fiction of Pure Absolute Space 20. Surface, Line, Point, etc., as Fictions 21. The Fiction of the Infinitely Small 22. The History of the Infinitesimal Fiction 23. The Meaning of the' As If' Approach 24. The Fictive Judgment 25. The Fiction contrasted with the Hypothesis Part 3: Historical Confirmations A. Kant’s Use of the ‘As If’ Method B. Forberg, The Originator of the Fichtean Atheism-Controversy, and his Religion of As-If C. Lange's 'Standpoint of the Ideal' D. Nietzsche and his Doctrine of Conscious Illusion. Subject Index Index of Names