 Husserl’s criticism of psychologism in the Prolegomena of the Logische Untersuchungen was the key text in the German-speaking debate over psychologism during the first decade-and-a-half of the twentieth century (Husserl 1900). The Prolegomena fall roughly into three parts. Part One identifies the sense in which logic is a ‘practical-normative discipline’ (Kunstlehre) (Chapters 1 and 2). Part Two argues at great length that the theoretical foundations of the logical practical-normative discipline are not psychological (Chapters 3 to 10). And Part Three provides an overview over the true foundations of logic as a practical-normative discipline (Chapter 11). I have reconstructed all three parts in some detail elsewhere (Kusch 1995, 41–60), here I shall concentrate on Part Two. (Important recent discussions of Husserl’s arguments include Carr 2007, Hanna 2008, Hopkins 2006, Moran 2008, Pelletier et al. 2008.)