Complex sentence: For Mouffe, the fact of the configuration social is the only foundational political stability-that and the certainty of a penultimate articulation's deferral: re-articulations of the social will always occur.
Split into simpler sentences: For Mouffe, the fact of the configuration of the social is the only foundational political stability-that and the certainty of a penultimate articulation's deferral. That is to say: re-articulations of the social will always occur.