most controversial teachings of Vatican II, making judgments as to their continuity or discontinuity with the prior Catholic tradition. The fundamental question at stake is this: Was the council an authentic development and extension of the prior doctrinal tradition, or was it in fact—at least in certain instances—an unabashed corruption of it? I will proceed in three main steps. I will outline the crucial issue at stake in understanding Vatican II, namely, the material continuity or discontinuity