The Norwegian author may also have used some of the many commentaries on the books of Holy Writ, in the production of which the medieval cloisters were so prolific. Of the influence of Petrus Comestor’s Historia Scholastica the writer has found no distinct trace in the King’s Mirror; but one can be quite sure that he knew and had used the Elucidarium of Honorius of Autun. The Elucidarium is a manual of medieval theology which was widely read in the later middle ages and was translated into Old Norse, probably before the King’s Mirror was written.[[7]] But our Norwegian author was not a slavish follower of earlier authorities: in his use and treatment of materials drawn from the Scriptures he shows remarkable independence. Remarkable at least is his ability to make Biblical narratives serve to illustrate his own theories of Norwegian kingship. He was acquainted with some of the legends that circulated through the church and made effective use of them. He must also have known a work on the marvels of Ireland[[8]] and the letter of Prester John to the Byzantine emperor,[[9]] in which that mythical priest-king recounts the wonders of India. But the chief source of his work is a long life full of action, conflict, thought, and experience.
The importance of the King’s Mirror lies in the insight that it gives into the state of culture and civilization of the North in the later middle ages. The interest follows seven different lines: physical science, especially such matters as are of importance to navigators; geography, particularly the geography of the Arctic lands and waters; the organization of the king’s household and the privileges and duties of the king’s henchmen; military engines, weapons, and armour used in offensive and defensive warfare; ethical ideas, especially rules of conduct for courtiers and merchants; the royal office, the duties of the king and the divine origin of kingship; and the place of the church in the Norwegian state.
In one of his earlier chapters the author enumerates the chief subjects of a scientific character that ought to be studied by every one who wishes to become a successful merchant. These are the great luminaries of the sky, the motions and the paths of the heavenly bodies, the divisions of time and the changes that bring the seasons, the cardinal points of the compass, and the tides and currents of the ocean.[[10]] In discussing these matters he is naturally led to a statement as to the shape of the earth. All through the middle ages there were thinkers who accepted the teachings of the classical astronomers who had taught that the earth is round like a sphere; but this belief was by no means general. Bede for one appears to have been convinced that the earth is of a spherical shape, though he explains that, because of mountains which rise high above the surface, it cannot be perfectly round.[[11]] Alexander Neckam, an English scientist who wrote two generations before the King’s Mirror was composed, states in his Praise of Divine Wisdom that “the ancients have ventured to believe that the earth is round, though mountains rise high above its surface.”[[12]] Neckam’s own ideas on this point are quite confused and he remains discreetly non-committal.
But if the earth is a globe, there is every reason to believe in the existence of antipodes; and if there are antipodes, all cannot behold Christ coming in the clouds on the final day. To the medieval theologians, at least to the larger number of them, this argument disposed effectually of the Ptolemaic theory. Job does indeed say that God “hangeth the earth upon nothing,”[[13]] and this passage might point to a spherical form; but then the Psalmist affirms that He “stretched out the earth above the waters,”[[14]] and this statement would indicate that the inhabited part of the earth is an island floating upon the waters of the great Ocean, by which it is also surrounded. This belief was generally maintained in the earlier centuries of the classical world, and it had wide acceptance in the middle ages. There were also those who held that beyond and around the outer Ocean is a great girdle of fire. It is likely, however, that many believed with Isidore of Seville that it is useless to speculate on subjects of this sort. “Whether it [the earth] is supported by the density of the air, or whether it is spread out upon the waters ... or how the yielding air can support such a vast mass as the earth, whether such an immense weight can be upheld by the waters without being submerged, or how the earth maintains its balance ... these matters it is not permitted any mortal to know and they are not for us to discuss.”[[15]]
There can be no doubt that the author of the King’s Mirror believed in the Ptolemaic theory of a spherical earth. In speaking of our planet he uses the term jarðarbollr,[[16]] earth-sphere. In an effort to explain why some countries are hotter than others, he suggests an experiment with an apple. It is not clear how this can shed much light on the problem, but the author boldly states the point to be illustrated: “From this you may infer that the earth-circle is round like a ball.”[[17]]
Toward the close of the medieval period there were certain thinkers who attempted to reconcile the spherical theory with the belief that the inhabited part of the earth is an island. These appear to have believed that the earth is a globe partly submerged in a larger sphere composed of water.[[18]] The visible parts of the earth would rise above the surrounding ocean like a huge island, and the Biblical passages which had caused so much difficulty could thus be interpreted in accord with apparent facts. It is quite clear that the author of the King’s Mirror held no such theory. In a poetic description of how the eight winds form their covenants of friendship at the approach of spring, he tells us that “at midnight the north wind goes forth to meet the coursing sun and leads him through rocky deserts toward the sparse-built shores.”[[19]] The author, therefore, seems to believe that the earth is a sphere, that there are lands on the opposite side of the earth, and that these lands are inhabited. He also understands that the regions that lie beneath the midnight course of the sun in spring and summer must be thinly populated, as the sun’s path on the opposite side of the earth during the season of lengthening days is constantly approaching nearer the pole.
But while the author seems to accept the Ptolemaic theory of the universe, he is not able to divest his mind entirely of current geographical notions. There can be no doubt that he believed in the encircling outer ocean, and it is barely possible that he also looked with favor on the belief that the whole was encompassed by a girdle of fire. On this point, however, we cannot be sure: he mentions the belief merely as one that is current, not as one accepted by himself.[[20]]
It was commonly held in the middle ages that the earth is divided into five zones, only two of which may be inhabited. This was a theory advanced by a Greek scientist in the fifth century before our era,[[21]] and was given currency in medieval times chiefly, perhaps, through the works of Macrobius.[[22]] At first these zones were conceived as belts drawn across the heavens; later they came to be considered as divisions of the earth’s surface. It will be noted that our author uses the older terminology and speaks of the zones as belts on the heaven;[[23]] it may be inferred, therefore, that he derived his information from one of the earlier Latin treatises on the nature of the universe.[[24]] For two thousand years it was believed that human life could not exist in the polar and torrid zones. Even as late as the fifteenth century European navigators had great fear of travel into the torrid zone, where the heat was thought to grow more intense as one traveled south, until a point might be reached where water in the sea would boil. The author of the King’s Mirror seems to doubt all this. He regards the polar zones as generally uninhabitable; still, he is sure that Greenland lies within the arctic zone; and yet, Greenland “has beautiful sunshine and is said to have a rather pleasant climate.”[[25]] He sees quite clearly that the physical nature of a country may have much to do with climatic conditions. The cold of Iceland he ascribes in great part to its position near Greenland: “for it is to be expected that severe cold would come thence, since Greenland is ice-clad beyond all other lands.”[[26]] He conceives the possibility that the south temperate zone is inhabited. “And if people live as near the cold belt on the southern side as the Greenlanders do on the northern, I firmly believe that the north wind blows as warm to them as the south wind to us. For they must look north to see the midday and the sun’s whole course, just as we, who dwell north of the sun, must look to the south.”[[27]]
On the questions of time and its divisions the author of the King’s Mirror seems to have had nearly all the information that the age possessed. He divides the period of day and night into two “days” (dægr) of twelve hours each. Each hour is again divided into smaller hours called ostenta in Latin.[[28]] Any division below the minute he apparently does not know. The length of the year he fixes at 365 days and six hours, every fourth year these additional hours make twenty-four and we have leap year.[[29]] The waxing and waning of the moon and the tidal changes in the ocean are also reckoned with fair accuracy.[[30]]
Medieval scientists found these movements in the ocean a great mystery. Some ascribed the tides to the influence of the moon;[[31]] others believed that they were caused by the collision of the waters of two arms of the ocean, an eastern arm and a western; still others imagined that somewhere there were “certain cavern-like abysses, which now swallow up the water, and now spew it forth again.”[[32]] The author of the Speculum has no doubts on the subject: he believes that the tides are due to the waxing and waning of the moon.[[33]]