Here then is the picture of a well-integrated and unified philosophy of history in which revelation in nature and revelation in Scripture are mutually meaningless without one another and mutually fruitful when taken together. To bring out the unity and therewith the meaning of this total picture more clearly, we turn now to note the necessity, the authority, the sufficiency and the perspicuity of natural revelation, as these correspond to the necessity, the authority, the sufficiency and the perspicuity