ASTROLOGY.
Besides those greater preventions which lay in the very structure and organised conceptions of society in the Middle Ages, the student of natural science was thwarted also by many lesser, which could not find place in this oration. Among the chief of these was judicial astrology, which supplanted and degraded the art of medicine.
It is difficult to carry the imagination into a time when the heavens were conceived as an animate and divine being[77], the heavenly bodies as active and intelligent parts of it, and the whole set not in illimitable space but around man and his home, and waiting upon him (vid. p. 47); yet without such an effort we cannot realise the ancient place and dominion of astrology. Such a possession when in its strength must have enthralled the human mind; and it abode tenaciously with the first scientific conceptions of celestial phenomena, even in the thoughts of the enlightened. Tycho Brahe, for many years of his life, was an adept; and even Kepler saw portents in the skies. When we read the doctrines of Aristotle on the celestial beings, it is indeed somewhat strange that upon him, upon Plato, and upon the Ionians, the “judicia astrorum” had even less hold than the mythology: so truly poised, even in the infancy of science, were the cosmic speculations of this wonderful race. The Romans by their Etruscan tradition held to astrology, chiefly derived from Chaldea and Egypt, and by them it was mixed with grosser folk magic; yet even in Rome there were many to repudiate it, not only such Grecian spirits as Cicero but also such Romans as Juvenal; as in Harvey’s time it was assailed by the irony of Pascal and of La Fontaine. Even in the twelfth century John of Salisbury had not failed to turn his light artillery upon astrology.
This art of forecast naturally attached itself closely to that of medicine; and in its decrepitude still it clung to medicine like a parasite. And as parasites in the field of pathology, so astrology brought with it other noxious superstitions and follies even worse than itself. In England it survived till the witty attack of Swift killed Partridge and astrology together; yet to this day many of its notions are embedded in our common speech.
Ptolemy among his good services did one ill to mankind by his Tetrabiblon or “Quadripertit,” an astrological treatise which was current with the Almagest in the Western Schools. This authoritative treatise, together with the Aristotelian conception of the heavens, gave to astrology the aspect of a regular science with its own principles and methods; a science admired and even courted by princes. As Frederick the Second and Charles the Fifth would learn of the stars the moment to take the field against their foes, so the medieval physician sought their countenance in the letting of blood or in the exhibition of a clyster or emetic. The Church, abhorring all concurrent dominion, and justly abhorring this bondage of the judgment of God and of the will of man, almost alone withstood the astrologer. If the doctors of theology did not know how to deny the power of the stars in the material cosmos, they vehemently denied it in the world of the spirit. “Et ideo pro certo tenendum est,” says Aquinas, “grave peccatum esse circa ea quæ a voluntate hominis dependent judiciis astrorum uti.” Of the priestly assailants of astrology, the most attractive to us for his wit, sagacity and sound knowledge, was Nicholas Oresme, sometime Bishop of Lisieux (died 1382), translator of the Ethics and other Aristotelian treatises, as he is portrayed for us by Hauréau (Dict. des Sciences philosophiques, art. Oresme) and M. Charles Jourdain. The fun of the thing is that the outspoken Oresme was the counsellor, the friend, and even the tutor of that notable astrologer Charles the Fifth; a story as honourable to the prince as to the subject. As Charles issued from the chambers of his astrologers the discourses of Oresme must have made him a little uncomfortable, especially when Oresme records the misfortunes of astrologising captains, such as Alphonso king of Castille, of whom, says he, I have heard nothing notable except that he cast horoscopes, was unfortunate in war, and neglected his kingdom; or such again as James the king of Majorca, a passionate astrologer, who on the dictation of the stars made a sortie against Peter of Aragon, and never came back again. It is all very well, says Oresme, for kings to know somewhat of the noble science of astronomy, but they must be content to hear of it in talk with sages, and not to spend upon the stars time and care which they should devote to the interests of their people. “Mesmement tele chose” (astrology, necromancy, geomancy and “quelconques tels ars”) est plus périlleuse à personnes d’estat, comme sont princes et seigneurs ausquelz appartient le gouvernement publique. Et pour ce ay je composé ce livret en françois afin que gens lais le puissent entendre, desquels, si comme j’ay entendu, plusieurs sont trop enclins à telles fatuités. Et autres fois ay je escript en latin de ceste matière” etc. In spite of the Bishop of Lisieux, astrology at the end of the fourteenth century reached the summit of its influence and popularity. In the course of his argument Oresme gives an admirable account of the nature of hallucination and the parts it may play in perverting knowledge; not only so but he explains also the fallibility of the normal senses in respect of organic defects, of media, of false inference, of association, of imposition of the imagination, and so forth. Under such circumstances, he says, a mystic might conceive himself to have been visited by an angel!