Moritz Schlick, one of the founders of modern analytical philosophy and a guiding spirit of the Vienna circle of logical positivists, was born in Berlin. He was a direct descendant on his mother's side of Ernst Moritz Arndt, the famous German patriot and political leader of the war of liberation against Napoleon Bonaparte. At the age of eighteen, Schlick entered the University of Berlin to study physics under Max Planck. He received his doctorate in 1904 with a dissertation on the reflection of light in a nonhomogeneous medium.

Schlick's familiarity with the methods and criteria of research in the natural sciences left him dissatisfied with the epistemological notions both of neo-Kantianism, which then dominated the German universities, and of Edmund Husserl's phenomenology, which had already become widely known. Instead, Schlick's starting point was the analyses carried out by Ernst Mach, Hermann von Helmholtz, and Henri...