This volume contains the English translation of Felix Kaufmann's (1895-1945) main work Methodenlehre der Sozialwissenschaften (1936). In this book, Kaufmann develops a general theory of knowledge of the social sciences in his role as a cross-border commuter between Husserl's phenomenology, Kelsen's pure theory of law and the logical positivism of the Vienna Circle. This multilayered inquiry connects the value-oriented reflections of a general philosophy of science with the specificity of the methods and theories of the social sciences, as opposed to abstract natural science and psychology....