Abstract
I examine implications for structural realism of Michael Friedman’s view about relativized a priori principles. Friedman's argument implies that there is structural preservation of constitutive principles in theory change, which suggests that the structural realist should be committed to these principles, given that they satisfy her criterion of ontological commitment. Since these principles are not regarded as representing physical structure, I argue that a dilemma arises for the structural realist. Either a distinction between mathematical structures that represent and mathematical structures that do not represent needs to be drawn, in order to block the structural realist from ontologically committing to relativized a priori principles, or the structural realist must ontologically commit to relativized a priori principles. Due to the dynamical nature of relativized a priori principles, the first option is untenable. The second option reveals implications for structural realism but also problems for Friedman's view