The most significant debate about the nature of science in the 20th century took place in London in 1965 between Karl Popper and Thomas Kuhn. Popper was a noted Viennese émigré philosopher who had already become famous as an advocate of "open society" in both science and politics. Kuhn, on the other hand, was a "rising" American ex-physicist-turned-historian of science who defended the much more professional, even authoritarian, concept of science. The debate itself has stalled, but the issues raised remain profound in their conflation of science and politics, knowledge and ethics. Kuhn v. Popper is a "fight for the soul of science" that preceded the original context of the Cold War debate and continues to this day. The book consists of short chapters - essays covering different aspects of the debate, with a glossary and bibliography at the end to make the contents of the book accessible to both specialist and lay readers.