So much attention to the Biblical story of creation and of Adam and Eve as is shown in the first two books of the _Causae et curae_ might give one the impression that Hildegard’s natural science is highly colored by and entirely subordinated to a religious point of view. But this is not quite the impression that one should take away. A notable thing about even her religious visions is the essential conformity of their cosmology and physiology to the then prevalent theories of natural science. The theory of four elements, the hypothesis of concentric spheres surrounding the earth, the current notions concerning veins and humors, are introduced with slight variations in visions supposed to be of divine origin. In matters of detail Hildegard may make mistakes, or at least differ from the then more generally accepted view, and she displays no little originality in giving a new turn to some of the familiar concepts, as in her five powers of fire, four of air, fifteen of water, and seven of earth.[355] But she does not evolve any really new principles of nature. Possibly it is the spiritual application of these scientific verities that is regarded as the pith of the revelation, but Hildegard certainly says that she sees the natural facts in her visions. The hypotheses of past and contemporary natural science, somewhat obscured or distorted by the figurative and mystical mode of description proper to visions, are embodied in a saint’s reveries and utilized in inspired revelation. Science serves religion, it is true, but religion for its part does not hesitate to accept science. [Sidenote: Peculiar views concerning winds and rivers.] We cannot take the time to note all of Hildegard’s minor variations from the natural science of her time, but may note one or two characteristic points in which her views concerning the universe and nature seem rather daring and unusual, not to say crude and erroneous. In the _Scivias_ she represents a blast and lesser winds as emanating from each of four concentric heavens which she depicts as surrounding the earth, namely, a sphere of fire, a shadowy sphere like a skin, a heaven of pure ether, and a region of watery air under it.[356] In the _Liber divinorum operum_ she speaks of winds which drive the firmament from east to west and the planets from west to east.[357] In the _Subtilitates_ Hildegard seems to entertain the strange notion that rivers are sent forth from the sea like the blood in the veins of the human body.[358] One gets the impression that the rivers flow up-hill toward their sources, since one reads that “the Rhine is sent forth by the force of the sea”[359] and that “some rivers go forth from the sea impetuously, others slowly according to the winds.”