Kepler's Witch (7 page)

Kepler's studies began with two years in the Faculty of Arts in preparation for three years of study in theology. The faculty lectured in Latin, allowing Kepler to hone his Latin, to learn Greek and Hebrew, and to study dialectics, mathematics, and rhetoric. At the end, he received his master's degree, coming in second out of fourteen. Because of his record, the chancellor of the university assigned him to study with Martin Crucius, the great classicist, and with Michael Mästlin, the great astronomer and mathematician.

In a short time, he developed a reputation as a dutiful scholar and a good fellow, if a bit of an intense one. He took part in the school plays, where he sang in the chorus and once or twice, because of his slight build, played a woman. He was also a bit of a prankster. One student, Zimmerman, the son of a Lutheran pastor, didn't like Kepler much, and Kepler didn't like him. The two young men were the antitheses of each other. Kepler was intense, chewing on ideas like they were meat; he didn't have much tact or patience for those who couldn't keep up. Zimmerman, too inert for study, too undisciplined for scholarship, simply wanted to sail through the university. So Kepler and a few of his friends sewed the arms of Zimmerman's gown shut, forcing Zimmerman to come to Matthias Hafenreffer's class armless. Hafenreffer told Superintendent Gerlack, who called in the pranksters. Kepler admitted it, denounced himself, and took his punishment, but that didn't stop the pranks.
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The other reputation he had developed was as an astrologer. Astrology was for the seventeenth century what economics is for the twenty-first. Astrology tried to form predictions about an uncertain future based on strict mathematical calculation, just as economics does with the laws of the market. Both are wrong about as often as they are right. Astrologers assumed that the heavens were never mute, but full of meaning, and that their meaning could be read as a text. Oddly enough, postmodernists say something similar about the world, that all things have sign value, and that nothing merely exists: a cigar is never simply a cigar. Stars and plan
ets in their complex relationships formed an alphabet. The fact that Mars was red, for example, said that it was hot and dry and warlike. Its place in the heavens meant that it had its allies and its enemies, and where it stood in the zodiac, in agreement with some planets and in opposition to others, had its effect on the world of human beings, an effect that could be read like a book.
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Because his love for puzzles and acrostics had started when he was a child, Kepler was particularly good at reading signs. He soon learned, however, that being a good astrologer required more than just math skills. One student, Rebstock, a fellow with a red face and beer breath, accosted Kepler in the hallway and demanded a horoscope. Kepler reluctantly agreed and, after obtaining the man's birth date, set to calculating his chart. What Kepler learned that day, however, is how dangerous it is to read all the signs. Rebstock's noisy drinking habits had to be taken into account, so Kepler predicted that the fellow would one day become a drunk, which wasn't much of a stretch. The stars tell all, but so does beer breath. Rebstock didn't like the report and forced his way into Kepler's room, where the two duked it out. The next day, Kepler asked Mästlin for advice. What should he do? If he was going to be an astrologer, he had to read all the available signs, and that included a beer breath, because the stars were so often hard to read. Sometimes his predictions worked and sometimes they didn't, so what could he do to make them more secure? Mästlin told him to just predict disaster. That would be bound to come true sooner or later.
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In Lutheran education, the Bible was foremost, and the method of biblical exegesis, the close reading and interpretation of original texts, informed all other disciplines. The method stripped away layers of accumulated interpretation to arrive at the original texts in the original languages and then built a new interpretation out of that. Kepler read Aristotle in the same way, especially the
Analytica Posteriora,
which set out Aristotle's logic, and the
Physica
and
Meteorologica,
which set out his ideas of motion and change in the world and sky inside the sphere of the moon. Oddly enough, Kepler says nothing about having read the
Ethics
or the
Topics.
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His inclinations as a scientist may well have surfaced even at this
time, in his reading choices in Aristotle. Early on, he was “taken by a forceful passion” for philosophy in general. He loved the fisticuffs of argument, the development of clear ideas, and the defense of them. In fact, this is the main way that Kepler complicated his life. The medieval tradition in education that Tübingen inherited included the staging of public disputations, debates in which students took opposite sides of an issue and argued it. Kepler learned to do this in Maulbronn and developed a liking for it that carried on into Tübingen. But Kepler could not take a position he didn't believe in, and his mind, ever active, was always searching for a new angle to an old question, a new solution to an old problem.

What he didn't understand was the wider world—that Tübingen and the Lutheran world in general felt themselves to be under siege, that in their growing orthodoxy the faculty of the
Stift
were not particularly interested in new approaches. New ideas are always dangerous in unsettled times, and for every good idea that comes along, an army of resistance emerges from the dust to squash it back down. Kepler's refusal to condemn the Calvinists over their doctrine of Communion made him suspect. His questions about the Lutheran ubiquity doctrine, which held that believers could receive the Body and Blood of Christ in Communion because Christ, being God, was everywhere, an idea that was a central part of the Formula of Concord, turned into a problem. Then he discovered Copernicus.

His philosophy professor at the university was Vitus Müller, who along with Martin Crucius taught him Aristotle and staged many of the students' public disputations. In his first years at Tübingen, Kepler read the works of Nicholas of Cusa and found the Catholic heretic's geometrical mysticism to be similar to his own. Crucius eventually led Kepler through the labyrinth, one by one introducing him to the philosophers who would dominate his thinking throughout his life—to Plato and the Neoplatonists and through them to Pythagoras. The secrets of the universe were in the shapes of things, in the geometry of the universe, and in that geometry there were harmony, order, and perfect reason. Throughout his life, Kepler would seek that harmony, and if he could never find it on earth, he would find it in the sky. He was impelled to do this, for it was central to his intellectual life. A boy who had grown up in a chaotic family in a
world where Christians preached hell to one another from their churches on opposite sides of the town square, where old women were regularly accused of witchcraft, and where emperors and princes sent armies tramping across people's farms and bloodying innocent peasants' wheatfields could either despair of all order and all civility or spend his life looking, as Kepler did, for a place where the universe made music.

Crucius was enamored of the Greeks, because they were the first, the inventors, the originators of the Western intellectual world. Whatever we think, they thought it first. For Crucius, anything not found in Aristotle could not be true.
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Kepler accepted this for some time, so much so that Crucius asked him to collaborate on his magnum opus, a commentary on Homer, to help him interpret the astrological and astronomical allusions in the poems, but the work was never quite satisfying to Kepler. His own inclinations were too different from his teacher's. Although both men were industrious and addicted to detail, Crucius was a gleaner, a gatherer of notions, while Kepler was a separator, splitting ideas into their purist form, skimming off the dross to find the gold.

Eventually this led Kepler closer to his final mentor, Michael Mästlin, who of all of Kepler's teachers had the greatest influence on his life. Mästlin introduced Kepler to the Copernican universe, and for the young Kepler it seemed as if a new window had opened in his mind. Typical of Kepler, he instantly began taking the Copernican position in his university debates and getting himself into trouble:

Meanwhile, as Kepler gushed about his new discovery and defended Copernicus as if he were a besieged city, Mästlin, the man who started Kepler along this track, stood by nonplussed. Mästlin was a short man, taciturn and introverted, who kept his more dramatic emotions calmly sealed away. He rarely smiled and yet was rarely angry. He had a high forehead and a narrow jaw, which made him look slightly bulbous. His hair was black, worn short, and he sported a bushy goatee, ubiquitous in the seventeenth century. He had made his fame by showing that a new star, a nova that appeared in 1572, had actually been a distant object and not some trick of the atmosphere. Conservative by nature, he was unwilling to part with Ptolemy completely, though he was aware of the growing complexity of the geocentric system, and he knew that even before Copernicus pressure had been building against the system for some time.

And yet no one had any proof. The weight of observation had been growing, seeding dissatisfaction among a number of astronomers, but such a momentous change would require a wealth of evidence. Copernicus himself had been afraid to publish until after his death. By Kepler's day, there were at least four distinct models of the universe floating through the intellectual air that were whispered about or heatedly discussed by clusters of students in the smoky dark corners of beer halls. First, there was the official cosmos, the geocentric, finite universe of Aristotle and Ptolemy, reiterated by St. Thomas Aquinas. Then there was the infinite cosmos of Nicholas of Cusa, with God at the everlasting, omnipresent center. Third, there was the “heliostatic” universe of Copernicus, in which the planets, including the earth, orbited the sun, which was fixed in place. And finally there was the model resurrected by Tycho Brahe, first discussed by Plato's student Heracleides Ponticus, in which the sun orbited the earth and the planets orbited the sun.
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Each of these systems had its supporters, and each had its detractors.

Surprisingly, the difficulty in adapting to the new placement of the earth in relation to the other heavenly bodies was not primarily that it spelled the downfall of human dignity. Later generations seemed to think that the geocentric model promoted the dignity of humanity's place in the universe, as the apple of God's eye, while the Copernican system turned this around and set the earth spinning meaninglessly through a meaningless universe. This is not quite accurate, for Aristotle never thought of the earth as a special place or the apple of anybody's eye. The earth occupied the lowest position in the cosmos, where all things chaotic and all things corruptible eventually settled. The world beneath the sphere of the moon was the privy of the universe, where living things came into existence and then died away, where sooner or later all life returned to rot.
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Only the heavens were eternal; only the heavens were divine. Redefining the earth as a planet, as Copernicus did, actually set the earth into the heavens with the other planets and raised property values all around.

Modern people, however, cannot fully understand or appreciate the Aristotelian model without also seeing it within its wider metaphysical framework. When Plato looked at the human person, he saw a paradox. First, there was the body—material, corruptible, an instrument for use on the material earth. Then there was the soul—immaterial, incorruptible, sharing in some fashion with the eternal and divine Ideas through its capacity for reason. What it could know, even vaguely, it could share in. These two halves of the human person were incommensurable, blind to one another. They spoke different languages, perceived the universe in different ways. Aristotle accepted this dichotomy and accepted their union within the human person, but admitted that it was one of the greatest mysteries of all. Somehow, these two parts were joined together by an intermediary substance, an apparatus so subtle that it was corporeal and incorporeal at the same time, so subtle that it approached the immaterial soul in essence, shimmering in the dark, and yet was still a body, able to join with the flesh and pass along the commands of reason. This substance, this astral body, the
pro–ton organon,
the primary instrument relating soul to body, was made of the same stuff, the same spirit,
pneuma,
that made the stars. The spirit that moved the heavens, that moved the
stars across the sky, was the same spirit that raised the human arm in greeting or moved the human leg in walking. The vast sky was not dead, then, but subtly, luminously alive, and we in our gross flesh were in some small way cosmic beings.
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Perhaps finally the Aristotelian universe was simply familiar. And it was beautiful, if a bit creaky. It did a good job synthesizing the appearances, the phenomena that people actually saw when they looked into the sky, and it looked reasonably similar to the Babylonian cosmos of Genesis. It was comfortable. It worked well enough for weekdays and sometimes on Sunday. The problem was that it was getting too complicated, and no mathematician liked that.