This chapter reconstructs Marx’s trajectory in the mid-1840s, showing how the unfinished “first critique of political economy” issues in a polemical critique of philosophy and of certain strands of socialism. It first examines the aftermath of the Manuscripts of 1844, arguing that Marx’s initial reflections on fetishism and alienation lead him to replace “reform of consciousness” with practice as the enabling condition of theory. The chapter then rereads Marx’s and Engels’s engagement with Max Stirner, maintaining that Stirner’s attack on “good causes” amounts to a radical, normativist critique of practical philosophy itself, that is, a critique of the very demand that emancipatory projects justify themselves by appeal to independent norms. Subsequently, it reconstructs selected sections of “Saint Max” in German Ideology, showing that Stirner’s critique of “family” and “political liberalism” falls short of a robust conception of critique insofar as it remains satisfied with criticising norms, whereas Marx and Engels are concerned instead with the historical genesis of those norms and thus treat all normative philosophical reflection, whether critical or justificatory, as a historically specific misrepresentation of social relations, that is, as ideology. Finally, the chapter argues that Marx consolidates a conception of critique in which the analysis of the material genesis of forms of consciousness displaces normative grounding as the basis for the critique of capitalist society, a strategy I call a “historical critique of practical philosophy”.