This basic principle implies that common sense and science must supply all
the essential factual knowledge, and that standards of ethics and justice must come from secular philosophies that rest upon uncontroversial assumptions.
Before the actual thesis regarding the
essential limits of the official Church in influencing life in the concrete can be stated, even in respect of the
knowledge necessary to such an influence (and not merely in respect of the
factual attainment of such
knowledge), a number of preliminary considerations are necessary.