The relationship between Vatican I and Vatican II is largely unexplored terrain in Christian theology. This lacuna in theological scholarship can be attributed, to a great extent, to the fact that the councils\u27 teachings are widely considered incompatible. The church\u27s inability to harmonize Vatican I\u27s and Vatican II\u27s teachings on ecclesiastical authority inhibits not only a more full reception of each council, but contributes to a sense that the church cannot offer a coherent presentation of some of its most central beliefs. This dissertation demonstrates fundamental compatibility between Vatican I and Vatican II by illustrating that they share many of the same intentions and concerns. It employs a method of distinguishing be...