Comprising excerpts from the documentary Philosophie Gegen Falsche Propheten (1974), or ‘Philosophy Against False Prophets’, this video is a robust primer on the ideas and legacy of Karl Popper. The influential Austrian-born thinker elucidates his concept of falsifiability, which holds that scientific theories can never be proven true, only demonstrated to be false, and discusses his political philosophy, using his book The Open Society and Its Enemies (1945) as a starting point. From his home in the Chiltern Hills outside London, Popper issues a rigorous defence of liberal democracy and a warning against the centralisation of power favoured by thinkers such as Plato, G W F Hegel and Karl Marx. He calls for modesty and clarity in both political ethics and science so as to pursue ‘a continuous approximation to the truth’ – even though we can never be certain when truth has revealed itself. A humane and enormously influential thinker, Popper’s ideas continue to resonate today, with both the liberal democratic order and the very concept of truth facing renewed threats worldwide.