Karl Popper (1902–1994) was one of the most provocative philosophers of the twentieth century. His relationship with the philosophers and scientists of the Vienna Circle led to his first book, The Logic of Scientific Discovery, which appeared in German in 1934 and presented his theory of the growth of scientific knowledge. On its publication in English in 1959, the book was described by the New Scientist as 'one of the most important documents of the twentieth century.' Popper emigrated to New Zealand in 1939 on the eve of World War Two. Reflecting on the tyranny sweeping through Europe, he wrote The Open Society and Its Enemies. Published in 1945, it remains his most compelling and widely read book. In 1946 Popper moved to the London School of Economics, where he taught until his retirement in 1969. This period saw the publication of The Poverty of Historicism, described by the Sunday Times as 'probably the only book which will outlive this century' and Conjectures and Refutations, a collection of many of Popper's classic essays. Karl Popper was knighted in 1965 and appointed Companion of Honour in 1982. He continued to write until his death in 1994.

• Introduction to the Routledge Classics Edition Jeremy Shearmur Dedication Preface Acknowledgements 1. Conjectural Knowledge: My Solution of the Problem of Induction 2. Two Faces of Common Sense: An argument for Commonsense Realism and Against the Commonsense Theory of Realism 3. Epistemology Without a Knowing Subject 4. On the Theory of the Objective Mind 5. The Aim of Science 6. Of Clouds and Clocks 7. Evolution and the Tree of Knowledge 8. A Realist View of Logic, Physics and History 9. Philosophical Comments on Tarski's Theory of Truth Addendum: A Note on Tarski's Definition of Truth Appendix 1. The Blanket and the Searchlight: Two Theories of Knowledge Appendix 2: Supplementary Remarks. Index

'Popper writes very skilfully and reasons strongly. Those who are determined not to be persuaded by him had best not read him.' - Peter Medawar, Nature