Quotation by Paul Tillich

There is ... a difference between the Protestant and the Catholic doctrine of the natural law. Catholicism believes that the natural law has definite contents, which are unchangeable and are authoritatively stated by the Church (e.g., the fight of the Roman Church against birth control). Protestantism, on the other hand, at least today and in this country, determines the contents of the natural law largely by ethical traditions and conventions; but this is done without a supporting theory, and therefore Protestantism has the possibility of a dynamic concept of natural law. It can protest against each moral content which claims unconditional character.