Kepler's Witch

by James A. Connor

  But for Kepler, the great work was accomplished, and he felt the wind shifting in his life, a sea change bringing along something new. Kepler realized that after printing the Rudolphine Tables, an important phase in his life had ended. He had been working on the Tables ever since the death of his old master. For twenty years, he had burrowed into the mathematics of Tycho’s observations and, with antlike labor, built the jumble of data into a set of tables that would revolutionize astronomy. It was over. He had done his duty to the emperor. So where would his life go from there? What he wanted, what he had always wanted, was a nice, comfortable position somewhere far away from the war and the endless bickering between Christians, a little position somewhere that would allow him to give lectures on things astronomical and astrological, where he could gather his family about him without having to leave them in some other city, and where he could live out his remaining years in peace and security. After years of struggle, he was willing to go anywhere, anywhere at all, in Germany, Italy—even England.

  He was fairly certain by that time that his days as imperial mathematician were coming to a close. After all, Emperor Ferdinand had already reinstated his Counter-Reformation measures in Upper Austria and was busy extending them throughout the empire. In the summer of 1627, Ferdinand had decreed that all non-Catholic officials in Upper Austria should be removed from their positions and encouraged to emigrate. Sooner or later, Ferdinand would remember that his imperial mathematician was also a Lutheran and would put him to the question as well. Kepler would not give in, no more than he did in Graz or Linz. Drowning in his depression—so much death, so many of his children lost!—Kepler imagined the worst.

  Nevertheless, he was required to bring the Tables to Prague to present them to the emperor, but he was afraid. That February, he had written to his friend Schickard that he had a “heart swarming with anxiety and stung by fear of the future, but a heart that could still find new hope in a single word of encouragement.”2 Fearing that Ferdinand would receive him badly, both for his Protestantism and for the tardy publication of the Tables, he decided he needed help, so he visited an old friend, Philip, Landgrave of Hesse, in October 1627 and asked the prince for his assistance.

  The landgrave was sympathetic and understood Kepler’s insecurity quite well. He knew how shaky Kepler’s position was and had always been. Philip referred the matter to his nephew Landgrave Georg, who had succeeded him as ruler of the principality. Georg had remained Catholic, loyal to the emperor and the Counter-Reformation, while his uncle Philip had become a Calvinist. Nevertheless, the two men were both well disposed toward the imperial mathematician and agreed to help him in any way they could. They advised him to go on to Prague, while they would write letters to people they knew.

  With Landgrave Georg’s help, Kepler gathered the remaining copies of the Tables and set out for Prague. He left Ulm on November 25, 1627, and on the way stayed with the Jesuits, especially Father Albert Curtius in Dillingen for two days. Oddly enough, for all his unmovable Protestantism, Kepler had an excellent relationship with the Jesuits, the chief architects and ideologists of the Counter-Reformation. As a Lutheran, he was expected to avoid them as the very spirit of evil, just as they were expected to see him as a heretic and an apostate. But the Jesuit motto to “find God in all things” was similar enough to Kepler’s own view of mathematics and astronomy that Kepler and the Fathers of the Society of Jesus found that they were kindred souls, that they were all men of scholarship and faith. His letters to them were always cordial, and so were his visits. Kepler enjoyed the intelligent conversation he found among them and often looked forward to his short visits to their houses. After a few days, however, he took leave of Curtius and traveled on to Regensburg, and from there went on to Prague.

  He found the city in quite a state of celebration. The first phase of the Thirty Years’ War was winding down, and it seemed as if Ferdinand had triumphed. The peasant revolt had been put down, and the last remnants of the Protestant rebellion had been cornered and their leaders killed. Wallenstein had defeated both Ernst von Mansfield and Christian von Braunschweig, the last two supporters of the exiled Winter King, Friedrich, and both men had died during the battle. Wallenstein was the man of the hour; his star was shining. He was the most successful general in the empire and had proven it. He was more successful than Tilly, more successful than anyone. He had fought the Danish king and pushed him back all along the northern part of Germany, until the Danes finally had retreated to a series of islands. A few weeks before Kepler arrived, Wallenstein had come to the city, set himself up in his opulent, some said decadent, new palace in the shadow of Prague Castle.

  The general had already been appointed the General Colonel Commander-in-Chief and the General of the Baltic and Oceanic Seas. He had risen so fast and had become so wealthy so quickly, that he was roundly hated in Protestant circles all across Europe and held in suspicion and fear in Catholic circles. Both France and Sweden, one country Catholic and the other Protestant, fretted about Wallenstein and schemed to bring him down. He was simply too successful, and his successes were too brutal and too final. The Swedes worried that the emperor might turn his eye northward, might convince himself that the Catholic church needed to return to Scandinavia. The French thought what the French always think, that the rest of Europe would be a better place if it were French. Nevertheless, as Kepler entered Prague, Wallenstein was the most celebrated man in the empire. People waved to him in the streets, knelt before him, kissed his hand, while plots within plots, schemes within schemes, swirled around the General Colonel Commander-in-Chief as the mist swirled above the Vltava River. The fact that he would one day be assassinated would have come as no surprise to the people of Prague.

  Kepler, of course, had no idea about any of this. He was not much of a politician and disliked intrigue in general. He saw in the love of power that drives so many great men the evil that had brought death to the world. Likely, all he noticed the day Wallenstein marched through the streets in triumph was a city in full celebration.

  He had work to do himself, however. He needed to present himself to the emperor. Putting it off as long as he could, he finally dragged himself up the Steep Stair to the castle and waited in the great hall to be announced to the emperor. Standing there, Kepler may have thought of his friend Jessenius and the headsman’s ax. But surprisingly, Ferdinand was in a splendid mood. His son, another Ferdinand, a boy who would later become Emperor Ferdinand III, had just been named king of Bohemia, an important stepping stone to the imperial throne, and was crowned at St. Vitus Cathedral with every bit of trumpeted glory that the Habsburg family could gather into one place. Which was considerable. The whole world was there, and Ferdinand was luminous with glory. He had gotten everything he wanted—power, fame, the ascendancy of the Catholic church—and then suddenly, standing before him, was his old imperial mathematician, nearly forgotten after years of war, a rarity in the imperial court, a man who had actually completed something. He had brought a book to present to his emperor, a copy of the Rudolphine Tables, named after Ferdinand’s unfortunate uncle Rudolf, that was a compilation and summary of the greatest work of astronomical observation of the time.

  Kepler thought he was about to be fired, but—mirabile dictu!—the emperor welcomed him kindly and with some ceremony. This fearsome Emperor Ferdinand, who had earlier cast him out of Graz, whom Kepler had dreaded for so long, was unaccountably gracious. And the court, whose halls he had haunted for so long waiting to be paid, was suddenly full of admirers. Kepler was another man of the hour, or as much of one as a mathematician could be. He was certainly no Wallenstein, but he had done his part, and the emperor praised him.

  Kepler’s depression, which had been partly fed by fear of this meeting, suddenly lifted like a morning fog burned off by afternoon sun. He was once again in Prague, the center of intellectual life in the empire, and he was the imperial mathematician, praised and admired by the court. The emperor was unaccountably pleased with him, and i
t seemed that, at least for now, his job was not in jeopardy.

  But so much had changed. Where were Kepler’s old friends? Tycho, his old master, was dead. Jessenius the peacemaker was dead. And where were the others? Where were the Lutherans, the Augsburgians, the Utraquists, and the Bohemian Brethren? All had disappeared. In Rudolf’s day the city had boiled with arts and arcane sciences, but in Ferdinand’s empire Prague Castle had become a true fortress. Soldiers were everywhere. The Old Town, which had once been a glorious hodgepodge of Catholic and Protestant and Jew, was now Catholic to the core. The Jews were still there, for they had been loyal to the emperor, which is one of the reasons so many of the Protestant uprisings quickly rampaged through the ghetto. But now, the Protestants were all gone, and the city seemed to have lost something of its feisty soul.

  Still, Kepler had to admit that the emperor was kind to him. Ferdinand bestowed on Kepler 4,000 gulden and commanded that the cities of Ulm and Nuremberg split the cost of it between them. Kepler never saw a penny of this money, but it was a nice thing for Ferdinand to say. Kepler asked to stay in the service of the emperor and to continue to live in Habsburg lands, and Ferdinand was more than happy to oblige. Ferdinand told him that he would find a position for Kepler at the imperial court and then perhaps a teaching position at one of the universities.

  But, of course, there was this little matter of Kepler’s religion. A trifle, really. Ferdinand let it be known quietly that Kepler would have to convert to Catholicism for all of these wonderful things to happen. After all, his own church had abandoned him, so where else could he go? Why not do it? He wasn’t really a Calvinist at heart—everyone knew that—and the position the emperor would find for him would be a good one. Why not convert? Some of his best friends were Catholic. Some of his relatives too. There were the Ficklers, who would be glad to welcome him back to the true faith. And even his own long departed father-in-law, Jobst Müller, had converted.

  At this point, the Jesuits appeared on stage. The Jesuits had befriended Kepler. He and Father Albert Curtius in Dillingen had been writing back and forth for years. Father Paul Guldin in Vienna, who had been raised a Protestant, but who as a young man had converted to Catholicism and joined the Jesuits, was a longtime friend. The last shoe finally dropped when Guldin, in a letter to Kepler, asked if he might be interested in joining the Catholic church. After all, there were great advantages in it, not only in this world but in the next. Kepler wrote back to him on February 1, 1628: “Just as I entered my life,” he wrote, “my parents initiated me into the Catholic church, sprinkled me with the holy water of baptism, and thus endowing me as a child of God. Since that time until now, I have never left the Catholic church.”3 Kepler, however, meant these words differently than the Jesuits meant them. Kepler believed that the Catholic church was not limited to those who accepted papal authority, but extended to everyone baptized in the name of Christ. Baptism, anointing with chrism, and faithful adherence to the teachings of Jesus were the marks of a true Catholic. Some Catholics followed Rome, while others followed the Augsburg Confession. “If you tell me that the church is that group of people united under one pope to spread the errors once cast off by the Augsburgians, and to rule them in matters of conscience, then you set forth the single characteristic which would prevent me from accepting the church you speak of, if this were offered by itself.”4 The rule of one pope could not define the church for Kepler. Only the rule of one’s conscience could do that. “Just as quarrels occur among the burghers and political factions of a city, so too, because of human frailty, mistakes happen among the citizens of the one church, separated by time and space.”5

  Kepler’s idea of the church was similar to the ideas expressed by St. Augustine in his City of God. There exists a mystical union among all believers, and differences between Christians, for all their violence, cannot destroy the Body of Christ. The divisions within the church are the result of human error, perhaps even human sin. They are not what God intended for us. This was the same belief that Kepler had already expressed to the members of his own church, a belief that had finally gotten him excommunicated. Who was this Kepler to council peace in the time of war? In some ways, the Jesuits were true friends at least, and for all their desire to convert him, they were willing to accept him when the Württemberg Lutherans would not. But he was still a potential convert, a possible victory for them and for the Roman Catholic church, and neither he nor they could forget that.

  Because of his baptism, Kepler believed, and therefore because of his membership in the Catholic church, he did not need the religious authority of the pope to teach him what the Scriptures and the fathers of the church had already taught him. Like a good Lutheran, he denied magisterial authority to any office within the church and reserved that authority to the texts of Scripture and tradition, and to the Holy Spirit that was granted to him in his baptism. He knew the religious practices and beliefs that he could not accept, ideas that in his view had built up over the centuries and that he considered to be dark innovations. He denied the adoration of Jesus in the Eucharist. Following Luther, he rejected the veneration of religious icons, pictures of saints, and even pictures of Jesus. He rejected the Mass as a sacrificial act, and the sharing of Communion only in the form of bread. The early church, he said, did not practice these things or hold these beliefs. He was not a proud man, he said, and recognized that the Catholic church was the mother church of the West. But he must obey Christ, whose rule commanded the church itself. “Therefore, do not think poorly of me, best friend, for I abide in the Catholic church. In order to reject what I do not consider to be Catholic or apostolic, I am prepared, not only to surrender the rewards which his Imperial Majesty has graciously and generously consented to offer me, but also to give up the Austrian lands, the entire kingdom, and even—and this weighs heavier than all the others—astronomy itself.”6

  Kepler would give up everything he loved and treasured in this world to maintain his grasp on his belief in God and Christ. He had to follow his conscience, which he could not surrender without surrendering his soul. For Kepler to give up his beliefs, beliefs that he had suffered so much over with his own church, would be to give up Christ himself.

  As in so many other times in Kepler’s life, the forces around him began to congeal all because he would not give up his conscience. Soon after he sent his letter to Guldin, he received a letter from the imperial representatives in Linz. The Reformation Commission (named as such, but actually a product of the Counter-Reformation) had reconvened, and Kepler, appearing on the list of non-Catholics, received a fairly standard letter commanding him to reveal himself ready or not ready to “accommodate” himself to the work of the commission. In other words, he would have to become Catholic or he would lose his position as district mathematician for Upper Austria. He had already told the Jesuit Paul Guldin that he was not willing to convert to Catholicism, which meant that sooner or later, he would lose his position as imperial mathematician. The fire was already lit; the Reformation Commission in Linz had merely added a bucket of coals to it. Kepler wrote again to Guldin, saying:

  I keep hold of the Catholic church. Even when it goes mad and thrashes about, I remain faithful to it with heartfelt love, as much as any frail human can do. Should the church accept me with my few small reservations, then I will persist in the perfection of my science under the leaderships of the dominant party. I am willing in silence and with full patience to carry on: I will abstain from all insults, mockery, hatred, hyperbole, calumny, and ridicule of any people who are of goodwill. I shall take to heart those sermons in which I see the light of divine grace; I shall make it my practice to avoid processions and the like, for I do not wish to give offense to anyone, and not because I am passing judgment on those who take part, but because such events mean two different things for two different people. Yes, I can also attend Mass and join my prayers with the prayers of the faithful, with one condition—if you accept my objection and that of all my family, to the degree that we
will not accept those things that our convictions tell us are in error—but are only asked to accept the general and final, sacred and Catholic purpose of the Mass, which is to raise to God our prayers and the offering of our praise and good works, always bearing in mind that unique sacrifice accomplished on the altar of the cross, that this sacrifice may be of good use for us, that the church may be taught by these historical acts about the memory of the death of the Lord.7

  In effect, Kepler was asking no more than what Thomas More had asked of Henry VIII. He would do none harm, he would think none harm. What he would do, to the limits of his conscience, would be to practice the faith within a Catholic milieu, if he could do so without causing scandal or division. But like Thomas More’s, Kepler’s own fame had worked against him. He could not be allowed to slink into the corners of the church, to spend his life in quiet and peace. He was famous, a man of science, a man whose conversion would be a great victory for the forces of Catholicism and the Counter-Reformation. He was an honest man, and was known to be honest. He was nonpolitical, and known to be nonpolitical. He was also known to have suffered on this account. If they could turn him, then their victory would have been that much sweeter. For the same reasons, then, that the Lutherans excommunicated him, the Counter-Reformation could not allow him to camp out in the middle between the great armies.