The movements of the four outer zones around each other, carrying the heavenly bodies with them, are attributed to the winds in each zone. The seasonal variations in the movements of the heavenly bodies, along with the recurring seasons themselves, are also determined by the prevalent winds, which, acting as the motive power upon the various zones, form a celestial parallelogram of forces. In this way is ingeniously explained also why in spring the days lengthen and in autumn they shorten until in either case an equinox is reached (Fig. [2]).
‘I looked and behold the east and the south wind with their collaterals, moving the firmament by the power of their breath, caused it to revolve over the earth from east to west; and in the same way the west and north winds and their collaterals, receiving the impulse and projecting their blast, thrust it back again from west to east....
‘I saw also that as the days began to lengthen, the south wind and his collaterals gradually raised the firmament in the southern zone upwards towards the north, until the days ceased to grow longer. Then when the days began to shorten, the north wind with his collaterals, shrinking from the brightness of the sun, drove the firmament back gradually southward until by reason of the lengthening days the south wind began yet again to raise it up’[60] (Plates [VII] and [VIII]).
Intimately bound up not only with her theory of the nature and structure of the universe but also with her eschatological beliefs is Hildegard’s doctrine of the elements. Before the fall of man these were arranged in a harmony,[61] which was disturbed by that catastrophe (Plate [XII a]),[62] so that they have since remained in the state of mingled confusion in which we always encounter them on the terrestrial globe. This mistio, to use the mediaeval Aristotelian term, is symbolized by the irregular manner in which the elements are represented in the central sphere of the diagram of the universe (Fig. [2]). Thus mingled they will remain until subjected to the melting-pot of the Last Judgement (Plate [XIII]),[63] when they will emerge in a new and eternal harmony, no longer mixed as matter, but separate and pure, parts of the new heaven and the new earth (Plate [XII b]).[64]
‘But the heavens and the earth, which are now,... are kept in store and reserved unto fire against the day of judgment and perdition of ungodly men.... But the day of the Lord will come ... in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.... Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness’ (2 Peter iii. 7, 10, and 13).
So Hildegard, acting on a scriptural hint, is enabled to dematerialize her doctrine of the after-things.
But although since man’s fall the elements have lost their order and their harmony on this terrestrial orb, yet is that harmony still in part preserved in the celestial spheres that encircle and surround our globe; and water, air, earth, and fire have each their respective representatives in the four concentric zones, the aer aquosus, the purus aether, the umbrosa pellis, and the lucidus ignis (Fig. [2]). These are the ‘superior elements’ which still retain some at least of their individuality and primal purity. From each of their spheres blows, as we have seen, one of the cardinal winds, and each wind partakes of the elemental character of the zone whence it issues, and has a corresponding influence on man’s body, since each of the four humours is specifically affected by the element to which it corresponds.
‘Then I saw that by the diverse quality of the winds, and of the atmosphere as they in turn sweep through it, the humours in man are agitated and altered. For in each of the superior elements there is a breath of corresponding quality by which, through the power of the winds, the corresponding element [below] is forced to revolve in the atmosphere, and in no other way is it moved. And by one of those winds, with the agency of sun, moon, and stars, the atmosphere which tempers the world is breathed forth’[65] (Plate [VII]).
This doctrine of the relation of the various winds to the four elements and through them to the four humours is found in the De Rerum Natura of Isidore of Seville, and is occasionally illustrated in European MSS. from the ninth century onward,[66] but we meet it set forth with special definiteness in the twelfth century in the translations from Messahalah. It is encountered also in the work of Herrade de Landsberg. In and after the thirteenth century it had become a commonplace.
The description we have given of the universe was in the main set forth by Hildegard in her first work, the Scivias (1141–50).[67] Subsequently she became dissatisfied with the account she had given, and while not withdrawing it, she sought in the Liber Divinorum Operum (1163–70) so to modify the original presentment as to bring it more into line with accepted views. Thus she writes: ‘There appeared to me in vision a disk very like that object which I saw twenty-eight years ago of the form of an egg, in the third vision of my book Scivias. In the outer part of the disk there was as it were the lucidus ignis, and beneath it the circle of the ignis niger was portrayed ... and these two circles were so joined as to be one circle.’ There was thus one outer zone representing the fire. ‘Under the circle of the ignis niger there was another circle in the likeness of the purus aether which was of the same width as the two conjoined [outer] fiery circles. And below this circle again was the circle of the aer aquosus as wide as the lucidus ignis. And below this circle was yet another circle, the fortis et albus lucidusque aer ... the width whereof was as the width of the ignis niger, and these circles were joined to make one circle which was thus again of width equal to the outer two. Again, under this last circle yet another circle, the aer tenuis, was distinguishable, which could be seen to raise itself as a cloud, sometimes high and light, sometimes depressed and dark, and to diffuse itself as it were throughout the whole disk.... The outermost fiery circle perfuses the other circles with its fire, while the watery circle saturates them with its moisture, [cp. Wisdom of Solomon, xix. 18–20]. And from the extreme eastern part of the disk to the extreme west a line is stretched out [i.e. the equator] which separates the northern zones from the others’[68] (see Fig. 3 and Plates [VII] and [VIII]).