  The best way to show how Critical Theory offers a distinctive philosophical approach is to locate it historically in German Idealism and its aftermath. For Marx and his generation, Hegel was the last in the grand tradition of philosophical thought able to give us secure knowledge of humanity and history on its own. The issue for Left Hegelians and Marx was then somehow to overcome Hegelian “theoretical” philosophy, and Marx argues that it can do so only by making philosophy “practical,” in the sense of changing practices by which societies realize their ideals. Once reason was thoroughly socialized and made historical, historicist skepticism emerged at the same time, attempting to relativize philosophical claims about norms and reason to historically and culturally variable forms of life. Critical Theory developed a nonskeptical version of this conception, linking philosophy closely to the human and social sciences. In so doing, it can link empirical and interpretive social science to normative claims of truth, morality and justice, traditionally the purview of philosophy. While it defends the emphasis on normativity and universalist ambitions found in the philosophical tradition, it does so within the context of particular sorts of empirical social research, with which it has to cooperate if it is to understand such normative claims within the current historical context.  After presenting the two main versions of this conception of philosophy, I turn to an illuminating example of how this cooperative relation between philosophy and the social sciences works from the point of view of the main figures in Critical Theory who sought to develop it: the critique of ideology, a form of criticism which if generalized threatens to undermine the critical stance itself as one more ideology. Even if Critical Theorists are united in a common philosophical project, this example shows the large differences between the first and second generation concerning the normative justification of social criticism.