It was but a step from faith in stellar influence on our earth to the belief that, as the heavenly movements were governed by immutable laws, so their influence upon the world would follow certain laws and its effects in the future could be determined as certainly as could the coming revolutions and conjunctions of the stars. Out of this two-fold belief was evolved a complex system of divination, the origin of which was forgotten as men, believing in it, invented reasons for believing, pretending that their faith was founded on a long series of observations. The Chaldeans believed that in discovering the unceasing regularity of the celestial motions, they had found the very laws of life and they built upon this conviction a mass of absolutely rigid dogmas. But when experience belied these dogmas, unable to realize the falsity of their presuppositions and to give up their faith in the divine stars, the astrologers invented new dogmas to explain the old ones, thus piling up a body of complicated and often contradictory doctrines that will ever be to the student a source of perplexity and astonishment.
On its philosophical side astrology was a system of astral theology developed, not by popular thought, but through the careful observations and speculations of learned priests and scholars. It was a purely Eastern science which came into being on the Chaldean plains and in the Nile valley. As far as we know, it was entirely unknown to any of the primitive Aryan races, from Hindostan to Scandinavia. Astrology as a system of divination never gained a foothold in Greece during the brightest period of her intellectual life. But the dogma of astral divinity was zealously maintained by the greatest of Greek philosophers. Plato, the great idealist, whose influence upon the theology of the ancient and even of the modern world was more profound than that of any other thinker, called the stars “visible gods” ranking them just below the supreme eternal Being; and to Plato these celestial gods were infinitely superior to the anthropomorphic gods of the popular religion, who resembled men in their passions and were superior to them only in beauty of form and in power. Aristotle defended with no less zeal the doctrine of the divinity of the stars, seeing in them eternal substances, principles of movement, and therefore divine beings. In the Hellenistic period, Zeno, the Stoic, and his followers proclaimed the supremacy of the sidereal divinities even more strongly than the schools of Plato and Aristotle had done. The Stoics conceived the world as a great organism whose “sympathetic” forces constantly interacted upon one another, governed by Reason which was of the essence of ethereal Fire, the primordial substance of the universe. To the stars, the purest manifestation of the power of this ethereal substance, were attributed the greatest influence and the loftiest divine qualities. The Stoics developed the doctrine of fatalism, which is the inevitable outcome of faith in stellar influence on human life, to its consequences; yet they proved by facts that fatalism is not incompatible with active and virtuous living. By the end of the Roman imperial period astrology had transformed paganism, replacing the old society of Immortals who were scarcely superior to mortals, except in being exempted from old age and death, by faith in the eternal beings who ran their course in perfect harmony throughout the ages, whose power, regulated by the unvarying celestial motions, extended over all the earth and determined the destiny of the whole human race.
Astrology, as a science and a system of divination, exerted a profound influence over the mediaeval mind. No court was without its practicing astrologer and the universities all had their professors of astrology. The practice of astrology was an essential part of the physician’s profession, and before prescribing for a patient it was thought quite as important to determine the positions of the planets as the nature of the disease.[139] Interesting evidence of this fact is found in the Prologue to the Canterbury Tales where Chaucer speaks of the Doctour’s knowledge and use of astrology as if it were his chief excellence as a physician:
“In al this world ne was ther noon him lyk
To speke of phisik and of surgerye;
For he was grounded in astronomye.
He kepte his pacient a ful greet del
In houres, by his magik naturel.
Wel coude he fortunen the ascendent
Of his images for his pacient.”[140]
Yet in spite of the esteem in which astrological divination was held by most people in the Middle Ages, Dante, the greatest exponent of the thought and learning of that period, shows practically no knowledge of the technical and practical side of astrology. When he refers to the specific effects of the planets it is only to those most familiarly known, and he nowhere uses such technical terms as “houses” or “aspects” of planets. But Dante, like the great philosophers of the earlier periods, was undoubtedly influenced by the philosophical doctrines of astrology, and a general belief in the influence of the celestial spheres upon human life was deeply rooted in his mind. To him the ceaseless and harmonious movements of the celestial bodies were the manifestations and instruments of God’s providence, and were ordained by the First Mover to govern the destinies of the earth and human life.
We can see this conviction of Dante’s with perfect certainty when we read the Divina Commedia. For Dante’s poetry is highly subjective; on every page his own personal thoughts and feelings are revealed quite openly. Chaucer’s poetry, on the other hand, is objective; he tells us almost nothing directly about himself and what we learn of him in his writings is almost entirely by inference. Chaucer’s frequent use of astrology in his poetry would make it hard to believe that he was not considerably influenced by its philosophical aspects, at least in the general way that Dante was. Part and parcel of the dramatic action in most of his poems is the idea of stellar influences. Yet we cannot assert, with the same assurance that we can say it of Dante, that Chaucer believed, even in a general way, in the influence of the stars on human life. In Dante’s poetry, as we have said, the poet himself is always before us. Chaucer, with Socratic irony, always makes it plain to the reader that his attitude is purely objective, that he is only the narrator of what he has seen or dreamed, only the copyist of another’s story. Even when Chaucer makes himself one of the protagonists, as in the Hous of Fame and the Canterbury Tales, it is only that his narrative may be the more convincing. He tells a story and makes its protagonists actually live before us, as individual men and women. It is possible to imagine all of his use of astrology in his poetry not as the reflection of his own faith in its cosmic philosophy, but the expression of his genius for understanding people and truthfully describing life and character.
Considerable discussion as to Chaucer’s attitude towards astrology has been called forth by passages in which he speaks in words of scorn with regard to some of the practices and magic arts that were often used in connection with astrology. In the Astrolabe after describing somewhat at length the favorable and unfavorable positions of planets he says:
“Natheles, thise ben observauncez of iudicial matiere and rytes of payens, in which my spirit ne hath no feith, ne no knowing of hir horoscopum.”[141]
Again in the Franklin’s Tale he speaks in a similar disdainful tone of astrological magic:
“He him remembred that, upon a day,
At Orliens in studie a book he say
Of magik naturel, which his felawe,
That was that tyme a bacheler of lawe,
Al were he ther to lerne another craft,
Had prively upon his desk y-laft;
Which book spak muchel of the operaciouns,
Touchinge the eighte and twenty mansiouns
That longen to the mone, and swich folye,
As in our dayes is not worth a flye:
For holy chirches feith in our bileve
Ne suffreth noon illusion us to greve.”[142]