It is interesting to find Bacon’s belief that the works of art and nature can exceed those of magic, and his charge that unscientific persons are confusing such works with magic, repeated by another writer. William of St. Cloud composed astronomical tables based upon his own observations during the period from about 1285 to 1321, in which he detected errors in the earlier tables of Thebit, Toulouse, and Toledo. This experimental astronomer, speaking of the powers of mirrors and lenses, such as those of Archimedes, those by which Caesar saw Britain from the shores of Gaul, and that by which Socrates discovered a dragon in the air, says: “These marvels and many others have been performed in ancient times, not by magic art, as some would have it, who are ignorant of the secrets of nature and of scientific industry, but solely by the force of nature and the aid of art.”[2220]
The two mathematics.
We now turn to Bacon’s attitude towards astrology, which we have already seen was an important factor in his “secret works of art and nature” as well as in his mathematics. He was aware that the mathematici or astrologers of the Roman Empire had been condemned by some of the church fathers, and were classed as practitioners of magic by more recent theologians and writers on Canon law. Like Isidore, Albertus Magnus, and other authors whom we have already discussed, Bacon gets around this by distinguishing two varieties of mathematics, one of which he says is magic, condemned by Cicero in his De divinatione and by other classical authorities as well as by the church fathers, the other a department of philosophy, a branch of which Augustine, Ambrose, Basil, Cassiodorus, and Gregory all approved. In the Opus Maius and Opus Tertium he states as usual that the “e” is long in the magical art of divination, while the vowel is short in the philosophical study; but in other writings he changed his mind and declared that “all the Latins” were wrong in this opinion and that the distinction was just the opposite.[2221] Bacon also cites Isidore’s distinction between two kinds of “astronomy”; one natural science, the other superstitious. Roger himself sometimes uses the words “astrology” and “astronomy” indifferently; sometimes speaks of “astrology” as speculative and “astronomy” as practical; sometimes distinguishes between speculative and practical astrology, of which the last includes judicial astrology.[2222]
Four objections to the forbidden variety.
Four features, to Bacon’s mind, distinguish the forbidden mathematica from legitimate judicial astrology.[2223] In the first place, it ascribes fatal necessity to the influence of the stars, whereas Bacon shows by an examination of the writings of Haly, Ptolemy, Avicenna, Messahala, and Isaac that learned and legitimate astrologers have never held any such tenet as fatal necessity, although common report may ignorantly ascribe such doctrine to them.[2224] In the second place, the practitioners of the magical variety of mathematics “invoke demons by conjurations and sacrifices to supplement the influence of the constellations, an execrable practice.” Third, “they mar their astrological observations by the idlest sort of circles, figures, and characters, and by the stupidest incantations and unreasonable prayers in which they put their trust.” Finally they often resort to fraud, employing confederates, darkness, deceptive mechanisms, and sleight-of-hand. By such methods “in which they know there is illusion” and “in which there is no virtue of the sky operating,” “they perform many feats which seem marvelous to the stupid.”[2225]
The rule of the stars.
While thus censuring the mathematica which is a subdivision of magic, Bacon declared that “it is manifest to everyone that the celestial bodies are the causes of generation and corruption in all inferior things.”[2226] Had not Aristotle in his treatise on Generation and Corruption said that the four terrestrial elements are related to the heavens as tools to an artificer?[2227] Bacon regarded the stars as ungenerated, incorruptible, and voluntary in their movements, which were regulated by angelic intelligences.[2228] He also accepted the usual technique of the astrological art in explaining the operation of this celestial influence.[2229]
Astrological medicine.
Bacon naturally subjected the human body to the constellations and was a firm believer in astrological medicine. If a doctor is ignorant of “astronomy,” his medical treatment will be dependent upon “chance and fortune.”[2230] Bacon holds not only that at conception and at birth one’s fundamental “complexion,” or physical constitution, is determined by the sky,[2231] but that with each changing hour our bodies are governed by a different planet whose characteristics the physician should know. Where Neckam[2232] had assigned six hours to the planet after which the day was named, that is, the first three and last three hours of the twenty-four, Bacon assigns it only four hours, namely, the first, eighth, fifteenth and twenty-second. Then, in order to bring the proper planet into control of the first hour of the succeeding day, he is obliged to have them follow each other in a different order in their rule of hours from that in which the days of the week are named.[2233] Bacon also distributes the parts of the body among the signs of the zodiac,[2234] and states that the physician must observe the moon carefully.[2235] He cites Hippocrates, Galen, the Centiloquium and Haly concerning the great influence of the stars both upon health and the administering of medicines.[2236] That the patriarchs of the Old Testament lived so much longer than men do to-day has been explained by many, Bacon says, as due to the stars. His explanation of the strange case of a woman of Norwich who ate nothing for twenty years and yet was during all that time in the best of health is that some constellation must have reduced the concourse of the four elements in her body to a self-sufficient harmony such as they seldom attain.[2237] Indeed, he goes so far as to hold that the resurrected body will have that harmony of the elements and so endure through eternity, no matter whether raised to the bliss of heaven or subjected to the consuming torments of hell.
Influence of the stars upon human conduct.