Kepler's Witch (2 page)

A
FTER HAULING MY STACK OF LUGGAGE
down the platform, I finally came across the last unclaimed seat on the night train from Stuttgart to Prague. Since no one shooed me away, I heaved my luggage into the upper bins and collapsed into the seat. Beside me were two Italian men who pretended to be asleep. Opposite them by the window was a blond German woman with a sack lunch on her lap. Beside her, in the middle seat, was a Korean boy, taller and lankier than I expected. He was traveling around the world, and in his broken English he said he wanted to know everyone's story. Across from me was a short, unnaturally thin German student with a buzz cut and an excess of earrings, sitting wound into himself in a sort of existential fetal position. I was not surprised when he pulled out a packet of cigarette papers and rolled his own.

“You an American?” he asked.

“That's right.”

“So what are you doing in Germany?” he went on, as if I alone had no right to be there.

“I'm writing a book about Johannes Kepler.”

“What makes you think we want to know what you have to say about Kepler? You cowboy Americans and your cowboy wars. How many people have you killed this week?”

He watched me, waiting for me to bite. I wanted to explain to him about World War I and World War II, but I didn't think this was the time. “Well, we were attacked, you see,” I said finally. “I was just across the river in Jersey at the time, so I saw it myself. So don't talk to me about our ‘cowboy wars.'”

The temperature in the compartment dropped considerably. People fidgeted and looked at one another nervously, wondering if there was going to be a shouting match. Discussing American foreign policy is only pleasant under the most controlled conditions, especially since I didn't agree with the policy myself, though I wasn't going to tell him that. The student leaned back in his seat, muttered “cowboys,” and pulled out a well-thumbed pocket edition of sayings from the Qur'an. For the next two hours, the trip rolled along pleasantly enough. The Korean student talked about his hometown and then all about the countries he had traveled through, counting them all on his fingers. The Italian men said they both came from Belluno, a city just north of Venice. The German woman spoke briefly, in German. One of the Italian men translated for the rest. She was on her way to visit her son, who was staying with his father, her estranged husband, who was in turn staying with his mother. Though they were not divorced, she worked and lived in Frankfurt, and her husband lived in a little town outside Berlin.

Suddenly, the student tucked his copy of the Qur'an back into his pocket and cocked his head at me.

“So why Kepler?” he said.

I looked at my shoes and thought about how to answer him. After a while, I looked up and said, “Because in 1620 Kepler's mother was being tried for witchcraft. Germany was well into the Thirty Years' War. Kepler had already lost his first wife and little boy to disease, and in the years following he lost three more children. In his adult life, he was chased out of one town after another by the Counter-Reformation. He was excommunicated by his own church. And yet, throughout most of these years he was writing a book called
The Harmony of the World.
This,” I said, “is a man worth knowing.”

The German student eyed me and sucked on his cigarette.

Since then, I have thought a good deal about this question. Great people show up now and then in this world. What makes them great is complicated. Some say Kepler was a genius, which he certainly was, but his scientific intelligence was not the source of his greatness. Johannes Kepler was one of the most powerful scientific minds of his century—he was an equal to Galileo in almost every way, a precursor to Newton, a man who had done the spadework for most of the important discoveries that defined science in the seventeenth century. And yet Kepler was also great in the way Gandhi and Martin Luther King, Jr., are great. He was a man who fought for peace and reconciliation between the Christian churches, even when it nearly cost him his life. Some people are born to greatness; some are made great by the events of their day. Some, such as King, Gandhi, and Kepler become great because they make choices full of moral courage. Kepler was a believing Lutheran and would never become a Catholic, even when it would have benefited his career to do so. People all around him were jumping from one church to another. Kepler's father-in-law did it. So did many of his acquaintances and rivals, simply to better their political or social position or not lose their earthly possessions. But Kepler believed in the Reformation; he believed in it with his soul. He stood fast with the Lutheran church, even when that church excommunicated him. When the Counter-Reformation chased the Lutherans out of their homes, he went with them, all the while fighting with the leaders of his own church in order to maintain the integrity of his conscience.

This book is a response to the question that the German student posed so succinctly—“Why Kepler?” Kepler is the man who finally confirmed Copernicus. He made a first, close attempt at defining a law of gravity. But above that, he was a man who contemplated in mathematics the glory of God. His life, his work, his mathematics were always about God. Everything he did was about God. Kepler found God in the hidden mathematical harmonies of the universe in as deep a way as he found God in the revelations of Scripture.

This is a man worth knowing. This book places him in his world, in his faith, in the events of his day. So why is Kepler not better known in our world? Everyone knows Galileo, even if all they know is that he was the
guy who fought with the pope. Most people at least know the name Copernicus and that he had something to do with a revolution. They know Newton as the guy who had an apple fall on his head. But many Americans do not even know Kepler's name; it's as if he has been written out of the history of science. The National Air and Space Museum in Washington, D.C., has almost nothing about him. Why? Kepler was, as author Arthur Koestler called him, the “watershed” where the medieval world finally gave way to the modern. After Kepler's time, the scientific movement codified its method, largely following the lead of Newton's
Principia.
Newton, whether by accident or design, kept his own personal thoughts and mystical speculations, of which he had many, out of his scientific writing, a practice that later became the model for the scientific mind-set—distant, observing, uninvolved.

After the death of Tycho Brahe, Kepler and Galileo were the preeminent astronomers of their day. If Galileo was the great observer, Kepler was the great theorist, and yet their relationship was not overly cordial. I suspect that some of this came from the fact that Kepler was a Protestant and Galileo was a Catholic, and despite all the astronomical ties that bound them together, that religious difference kept them apart. Both men suffered for their religion. Both men helped to fashion the scientific world. And yet Galileo has come down to us through history as the martyr for science, while Kepler has been treated by some as a sort of embarrassment. This is largely, I believe, because Kepler did not wish to separate his science from his metaphysics or his metaphysics from his mysticism. He could not therefore fit the profile of the perfect scientist as it formed itself in the century after his death. Kepler did not have enough scientific cool—neither did Galileo or Newton for that matter, but when mythologies fashion themselves, such things don't matter.

This mythology that gathered around Newton and Galileo, this pseudo-history, pictured the scientific method, the method of the plodding empiricist, as free of metaphysical speculation and exploding from the heads of these two men, entire. But in truth, real history is always much more complicated than myth, and men like Kepler, sometimes forgotten, played a bigger role than the myth would allow. In my grumpier mo
ments, I suspect that Galileo has been given his part in the myth because he fought with the pope, which made him a scientific Hercules. In my less grumpy moments, I suspect that there is some truth to the myth, because Kepler's mind, as it appeared in his work, was far-ranging. Was Kepler a scientist, a philosopher, or a theologian? The answer is yes to all three. Scientific work for Kepler was always grist for his theological mill, a chance to praise God.

In some ways, the whole problem comes down to Newton, who either by accident or by intent failed to give Kepler the credit he deserved. And some of Newton's own friends and supporters, including the Scottish astronomer David Gregory and the English astronomer Edmond Halley, of the comet fame, chided Newton for not giving Kepler proper recognition.
¹
I suspect that Newton, the archegotist, in his darker moments knew quite well what he owed to Kepler, who had brought him right up to the doorstep of his theory of gravitation, who had laid the foundation for his work on optics, and who, as Leibniz recognized and Newton dismissed, had set the stage for the invention of calculus. He knew what he owed to Kepler but would not acknowledge it.

But this seems almost too appropriate to the rest of Kepler's life. He was a man caught between the grinding wheels of history, not only religious history, but scientific as well. In the last part of his life, he struggled through the first years of the Thirty Years' War, the war between Christians in which Reformers and Counter-Reformers tore at the body of the faith. Everyone suspected everyone, and Kepler, who would not abandon his own beliefs, suffered excommunication from his own Lutheran church on the basis of those suspicions. Sadly, much the same thing happened to him after his death at the hands of the scientific community.

If I have any mea culpas to make in this book, one is this—I did not try to give an account, except as a sketch, of Kepler's science. There are many great books about his science, and they are listed in the Source Readings. Read them, for they are more than worth the effort. This book, rather, is about Kepler's life, about his suffering and his triumphs. Perhaps if you read this book, knowing Kepler will make your own life work a little better.

I have alternated the chapters in
Kepler's Witch
with translations of Kepler's letters and journal entries. They tell the story, in Kepler's own words, of the crises he suffered. The best part about studying letters is that you find that great people in history are no longer legendary figures, but ordinary human beings caught in mundane torments. In studying Kepler, I found that all of his discoveries were made against deep opposition and were the result of tenacity. He never achieved anything easily.

The translations are keyed to the main events in Kepler's life. Some of these events are complex, for they span the length of Europe and sometimes cover a period of a century or more. This makes the translations crucial to the story. But more important, far too little of Kepler's writing has been translated into English. Mind you, a network of scholars has over the years translated most of his greater scientific works, usually from Latin, but the kitchen details, the facts of his daily existence, have been left out.

Still there have been some marvelous, informative biographies of Kepler, most notably the one by Max Caspar entitled, prosaically,
Kepler.
Every Kepler biographer owes mountains of gratitude to Caspar, and I am no exception. With the help of Martha List, Caspar collected and edited all of Kepler's sundry writings, from his scientific work to his letters to the account of his mother's witchcraft trial. This gigantic library-sized collection is still in print, and I bought a good chunk of it myself. It is called
Johannes Kepler Gesammelte Werke,
referred to in the notes as
GW.
As often as I could, I returned to the
GW,
ferreted out the original German, and translated it myself. But translating it into readable modern English was not always easy, for several reasons. Kepler wrote in both German and Latin. His Latin style was impeccable, but his German, though his native tongue, was not very good, often florid and overly ornate. In addition, he wrote in what is now called
Frühneuhochdeutsch,
a transitional form of German that is neither medieval nor modern, a form that evolved quickly into later variants that in turn evolved into modern German. It is only now being recovered by scholars.

All of this to dig out the life of a man worth knowing. The rest of that train trip, the German student and I talked about Kepler. When he left the train, he shook my hand and said, “Good day.” A beginning.