 Popper took some time to settle on a career; he trained as a cabinetmaker, obtained a primary school teaching diploma in 1925 and qualified to teach mathematics and physics in secondary school in 1929. He undertook a doctoral programme with the department of psychology at the University of Vienna, then under the supervision of Karl Bühler, one of the founder members of the Würzburg school of experimental psychology. Popper’s project was initially designed as a psychological investigation of human memory, on which he conducted initial research. However, the subject matter of a planned introductory chapter on methodology assumed a position of increasing pre-eminence and this resonated with Bühler, who, as a Kant scholar (a professor of philosophy and psychology), had famously addressed the issue of the contemporary “crisis in psychology”. This “crisis”, for Bühler, related to the question of the unity of psychology and had been generated by the proliferation of then competing paradigms within the discipline which had undermined the hitherto dominant associationist one and problematized the question of method. Accordingly, under Bühler’s direction, Popper switched his topic to the methodological problem of cognitive psychology and received his doctorate in 1928 for his dissertation “Zur Methodenfrage der Denkpsychologie”. In extending Bühler’s Kantian approach to the crisis in the dissertation, Popper critiqued Moritz Schlick’s neutral monist programme to make psychology scientific by transforming it into a science of brain processes. This latter ideal, Popper argued, was misconceived, but the issues raised by it ultimately had the effect of refocusing Popper’s attention away from Bühler’s question of the unity of psychology to that of its scientificity. This philosophical focus on questions of method, objectivity and claims to scientific status was to become a principal life-long concern, bringing the orientation of Popper’s thought into line with that of such contemporary “analytic” philosophers as Frege and Russell as well as that of many members of the Vienna Circle.