Buddhadasa Bhikkhu (1906-1993) is widely regarded as modern Thailand's most influential Buddhist philosopher. His thought had a profound intellectual impact in Thailand in the second half of the twentieth century. His life mission was to undertake a complete reexamination of Theravada Buddhist teachings. By returning to the Buddha's original teachings in the Suttapitaka and by drawing on aspects of Zen Buddhism, Buddhadasa crafted a vision of Thai Buddhism as a socially, politically, and intellectually progressive force. This vision of a modern Theravada Buddhism fit for a modern, democratic, and socially just Thailand continues to inspire large numbers of Thai people in the twenty-first century. In this book Peter Jackson examines Buddhadasa's life work and thought, placing them in the context of the political, economic, and intellectual changes that transformed Thailand in the twentieth century. Combining biographical studies with critical philosophical and sociological analyses of Buddhadasa's reforms of Thai Buddhist teachings, Peter Jackson emphasizes the path-breaking and often radical ideas of one of the greatest Buddhist thinkers of the last century. This book is a revised and expanded edition of Peter Jackson's Buddhadasa: A Buddhist Thinker for the Modern World, published in 1988. It contains a new epilogue tracing the controversy surrounding Buddhadasa's death in 1993 and reflecting on the philosopher-monk's lasting legacy in Thailand.