ABSTRACT
Karl Popper was one of the most famous philosophers of the 20th century and that one would have occasion for his 100th birthday to hold a convention in his former hometown of Vienna in his honor, was in his youth still not in sight. Popper's first philosophical interlocutor, Julius Kraft, was not only a scholar of Leonard Nelson, in the academic sensebut also his political follower. Nelson had already attracted attention as a cognitive epistemologist, especially science and mathematics, at a young age, including the lifelong interest of the famous mathematician David Hilbert. The central element of Nelson's critique of democracy is the idea that it can be abolished by its own means, namely the majority decision. Nelson begins his reflections with a proof of contradiction not in the case of democracy but of authoritarianism. Popper's formulation of a downright "logical" critique of democracy, that is, a paradox of democracy, can be found in The Open Society and its Enemies.
