“Ideal theorists” in contemporary liberal political theory argue that we can only arrive at a conception of what our most important political values require by reference to an imagined ideal state of affairs and that we must therefore, to some extent, engage in utopian thinking. Critical theorists, from Marx and the Frankfurt School, have traditionally been highly skeptical towards using idealizations in this way. This skepticism is mirrored by contemporary authors, such as Charles Mills. I argue that most of their critical arguments make a principled case only against ahistorical, decontextualized projects of utopian idealization, but not against ideal theorizing as such. Critical theories do not need to reject ideal theorizing. On the contrary: The method of immanent critique that is specific to critical theory allows for a conception of an ideal state of affairs that emerges from its diagnosis of social contradictions. I conclude that critical theories can (and should) incorporate some aspects of ideal theorizing and its utopian reference to a better society.