In this paper I argue that Fichte's attempt to reconcile the dualism of concept and intuition requires the overcoming of any idea of a thing-in-itself. At the same time he preserves the idea of an external constraint on the I's self-positing. This central role for the realist constraint of the check conflicts with recent interpretations of Fichte that see his project as advocating the exclusivity of the space of reasons. The striving subject confronts and unifies the opposition between the realistic (...) and idealistic elements in the Wissenschaftslehre. It is argued that as striving, reason's drive for self-determination is a process of self-transformation, as consciousness confronts the limitations of its inadequate explanations of the objects of experience. (shrink)