Whereas principles are derived from the world, an ideology is a harmonized set of ideas, abstracted from theories and collated into a system, which seeks to direct the world according to its vision. Communism offers the most notorious example of ideology as an abstraction brought together into a theory or system to which the world is forced to conform. So, is Catholicism an ideology? As Joseph Ratzinger writes in Introduction to Christianity, the faith “is not a reconstruction or a theory but a present, a living reality.” It offers a way of living that imitates and leads to Jesus Christ.