Sir Karl Popper is widely acclaimed as one of the most influential thinkers of our time. Born in Vienna in 1902, he fled the Nazis in 1937 and took up a university post in New Zealand. He followed a distinguished academic career, teaching and lecturing all over Europe, Australasia, India, Japan and the USA. He has written numerous books, articles and essays. His publications appeared in some thirty languages. This study offers an accessible introduction to the life and work of this extraordinary thinker. It charts the development of Popper's philosophy and shows his unfailing political commitment to humanism and enlightenment. At the centre of Popper's thought stands rationality and a strong belief in the power of the human mind to change things for the better. Rationality thus serves as a guide both in his philosophical considerations and for his political views. Approved by Karl Popper himself as a sympathetic and comprehensive study, An Introduction to the Thought of Karl Popper will be ideal to meet the increasing demand for a summary introduction to his work.