For of Meridians, and Parallels
Man hath weav'ed out a net, and this net throwne
Upon the Heavens, and now they are his owne.

--"An Anatomy of the World: The First Anniversary," John Donne

What I am going to relate is the solution to a mystery. It is, I confess, a mystery that I might well have solved thirteen years ago when I first came across it. I can only plead distraction.

In 1983 I was sent for review by The New Yorker magazine Daniel Boorstin's then newly published book The Discoverers. It may be remembered that this was Boorstin's kaleidoscopic account of the history of scientific discovery from Aristotle to Einstein. I found the book somewhat maddening--a mixture of brilliant insights, incorrect statements, and paths not followed. Among the latter was the following sentence that came just after Boorstin had quoted the famous lines of John Donne taken from his poem "An Anatomy of the World: The First Anniversary": "And new Philosophy calls all in doubt / The Element of fire is quite put out ....," which refers to the new astronomical discoveries of Copernicus, Galileo, and Kepler. Boorstin then casually remarks, "In 1619, when Donne visited the Continent he took the trouble to visit Kepler in the remote Austrian town of Linz."

When I first read this laconic sentence, I remember sitting bolt upright in my chair. Boorstin was announcing an encounter between arguably the greatest poet of the late sixteenth and early seventeenth centuries and unarguably one of the greatest astronomers who has ever lived. But that is all he does--just announce--no explanation, nothing. As I wrote in my review, "One longs to know what they talked about--even in what language. Kepler was always desperate to find converts to the Copernican system. What effect did the encounter have on the two men? Did it relieve the anxiety about the new cosmology which Donne suggests in the line (from the same poem) "Tis all in peeces, all cohaerence gone ...'?" In fact, did this unlikely encounter take place at all? How does Boorstin know? There are no specific references in his book. One is at a loss. This was the mystery, and I more or less forgot about it for the next twelve years.

This past summer I happened to pick up The Varieties of Metaphysical Poetry by T. S. Eliot. When I saw the book I immediately thought back to the old mystery: Did Donne meet Kepler? But I soon found that on this Eliot was no help either. Kepler does not appear in the index, and neither do Copernicus or Galileo for that matter. The science in Donne's poetry was not Eliot's concern. Nonetheless, I was now determined to find out about this meeting. I decided that the next thing to do was to have a go at Kepler directly. The way to start was to have a look at the Kepler entry in the Dictionary of Scientific Biography. Here I drew blood--a droplet. The Kepler entry, which runs to more than twenty pages, was written by Owen Gingerich of the Harvard-Smithsonian Center for Astrophysics. Gingerich, who is both an astronomer and a historian of science, has made many studies of Kepler. He is an expert and a man to be taken seriously. Toward the end of his entry I found the sentence "... in 1619 the English poet John Donne had visited him [Kepler] in Linz, and in 1620 the English ambassador Sir Henry Wotton had called on him in Linz and had invited him to England." Since this was published in 1973 and since Boorstin's book was written in 1983, a reasonable assumption is that the latter had gotten his information from the former. But Gingerich, like Boorstin, offered no specific documentation. I had no more idea of the details of the visit than I had had before. However, Gingerich did offer an extensive bibliography.

Two of the books seemed both relevant and accessible. The first was a biography by the late Max Caspar called simply Kepler. Caspar, who died in 1956 at the age of seventy-six, spent much of his life studying Kepler and was considered the leading scholar on the subject. Among other things, he was responsible for editing Kepler's complete oeuvre, including, important for what follows, his vast correspondence. The only other scientist of comparable ability that I know of who wrote so many letters was Einstein. Caspar's biography is quite wonderful, and very readable, but of Donne there is not a word.

Gingerich also cited Arthur Koestler's The Sleepwalkers. This is a fascinating book in which Koestler, with a novelist's eye, studies the character of the scientists, including Kepler, who created the New Astronomy. There are several references to Donne, many of which make the interesting point that in Donne's prose polemic Ignatius His Conclave, Kepler and the other New Astronomers are mentioned by name, indicating that Donne was familiar with their work. But of the hypothetical meeting of the two men there is not a word. Given Koestler's interest in this kind of personal detail, one can only assume that when his book was published in 1963 no one knew about the meeting. That, it turns out, is correct. Something, therefore, must have happened between 1963 and 1973 when Gingerich made his reference.

This was as far as I was able to go with Kepler, at least using references that were available to me, so I decided to return to Donne. The standard biography of Donne was written by the late R. C. Bald. Professor Bald did not live to finish his book, which was completed by W. Milgate of the Australian National University. It is a splendid biography, but there is only one mention of Kepler. This has to do with whether or not Donne read and was influenced by Kepler's science fiction novella, Somnium, which was circulating in manuscript form during Donne's lifetime. It was only published after both Kepler and Donne had died. Unlike Professor Bald, and for reasons I will explain, I do not find the evidence for this particular influence of Kepler on Donne very convincing, but, in any event, there is in Bald's book no suggestion that the two men actually ever met.

The book does make it quite clear that the only time Kepler and Donne could have met was in October of 1619. In February of 1619 James Hay--Lord Doncaster--had been given a diplomatic mission on the Continent by King James I to try to mediate the growing tensions between Catholics and Protestants in Middle Europe. The King had also appointed Donne chaplain to this mission. During the summer and fall of 1619, the mission wound its way eastward through Europe in the quest of one last meeting with the recently anointed Holy Roman Emperor Ferdinand of Styria in the hope of enlisting his help in this mediation. Doncaster, who had met unsuccessfully with Ferdinand earlier, finally caught up with him again in early November in Graz--an encounter that Donne witnessed. From Bald's book we learn that Doncaster--and presumably Donne--had, prior to this encounter, sailed down the Danube from Germany to Vienna, where they arrived on November 2. They then proceeded to Graz. But Linz was on the way to Vienna. One would therefore guess from Bald's chronology that any meeting between Donne and Kepler had to have taken place before November 2 while the party was proceeding on the Danube to Vienna.

Now I felt myself closing in. I had pinned down the approximate date of the meeting and even the circumstances. But I was completely stuck. What to do next? It occurred to me to put my problem to a colleague. For the last few years I have been exchanging information about the World War II German nuclear program with a young historian of science named Cathryn Carson. Carson does not work in the history of seventeenth-century astronomy, but she did get her degree at Harvard. Perhaps she had taken a course with Gingerich and the subject of Kepler and Donne had come up. I e-mailed her at Berkeley, where she is now teaching. She replied that she had never heard. of the meeting but she would e-mail Gingerich. Shortly thereafter she sent me a copy of an e-mail she had received from Gingerich. It had the missing reference! But it was something of a surprise. The reference was to a 1971 article entitled "Donne's Meeting with Kepler: A Previously Unknown Episode," which had appeared in the Philological Quarterly, written by a man named Wilbur Applebaum. I confess that neither the name of the author, nor of the journal, was familiar to me, though I later learned that it is a standard journal in its field and that Applebaum was an eminent historian of science. The Berkeley library had the journal and, in short order, Carson faxed me a copy. The mystery was now about to be solved--I hoped.

Applebaum, who was then at the University of Illinois, had made his discovery, I guessed from his brief three-page note, while he was perusing the edited version, which Caspar had done in collaboration with Walther von Dyck and Franz Hammer, of Kepler's collected works. (Later, he informed me that when he was looking through the index, he had come across an entry on Donne that immediately aroused his curiosity.) In volume 16, Applebaum discovered a letter that seems to have been completely overlooked by both Donne and Kepler scholars. He does not present the letter in full or even say what language it was written in--German, it turns out--but he does give a few of the essentials. There is no date on the letter and the correspondent, who, though Applebaum does not tell us, turns out to be a woman, is unnamed. The editors, as Applebaum points out, have supplied the wrong date--namely, 1608--as the date of the letter. The letter refers to an event that could only have taken place in 1619--Kepler's meeting with Donne and Lord Doncaster--spelled "Dancastre" in the letter. Donne is referred to as Doctore Theologo, which also helps to date the letter, since he did not receive this honorary doctor's degree from Cambridge University until March of 1615. The letter even fixes the meeting as having taken place on October 23, which fits the chronology adumbrated by Professor Bald.

I will not try to discuss the contents of the letter here, but will come back to it when I explain, as nearly as I can tell, why there was such a meeting and what, if anything, were its consequences. Needless to say, once I learned of this letter, I asked Carson if she could find it in the Berkeley library edition of Kepler's collected works. This she did. At the end of Applebaum's note, he muses, "It would be interesting if Donne scholars could discover any reference in Donne's works or manuscripts to his meeting with Kepler." It would indeed. Certainly no one came forward in response to my query in The New Yorker, and, Applebaum informed me, no one came forward to answer his request either. But now allow me to reconstruct the "world-lines"--the trajectories in space and time--that led to this extraordinary encounter on October 23, 1619.

Johannes Kepler was born on December 27, 1571, in the small Swabian town of Weil-der-Stadt in southwest Germany. One of the pleasures in studying the life of Kepler is reading his own version of it. Until the present vogue of scientists writing with increasing enthusiasm about what Einstein called, with some scorn, the "merely personal," no scientist--certainly no great scientist--has written about him or herself with the candor of Kepler. Of his father, a professional soldier who deserted the family, Kepler wrote that he was "vicious, inflexible, quarrelsome, and doomed to come to a bad end. ... [He] treated my mother extremely ill, went finally into exile and died." Of his mother, Kepler wrote that she was "small, thin, swarthy, gossiping and quarrelsome, of a bad disposition." What Kepler could not have foreseen when he wrote this was that beginning in 1615 he would spend the next six years defending his mother from the charge that she was a witch. The denouement occurred in the fall of 1621 when, under threat of torture, his poor mother insisted that she had nothing to admit. She was freed, but died a few months later.

Kepler was equally hard on himself. In the family horoscope he produces a chronology that, as Koestler notes, reads like "the diary of Job." He notes that at age fourteen and fifteen he "suffered continually from skin ailments, often severe sores, often from the scabs of chronic putrid wounds in my feet which healed badly and kept breaking out again. On the middle finger of my right hand I had a worm, on the left a huge sore." This dreadful litany continues through 1592, when, at age twenty-one, he reports: "At Cupinga's I was offered union with a virgin; on New Year's Eve I achieved this with the greatest possible difficulty, experiencing the most acute pains of the bladder."

At about the same time, Donne, who was a few months younger than Kepler--his exact birth date is uncertain--was being described by a contemporary as a "great visitor of Ladies, a great frequenter of Playes, a great writer of conceited Verses." In fact, it is likely that most of Donne's magnificent love poems--"For God's sake hold your tongue, and let me love ..." were written before he was twenty-five--written, as he later said, by "Jack Donne" and not "Dr. Donne." Kepler was twenty-six when he produced his Job-like horoscope. If Donne had actually met Kepler at this time, he would almost certainly have thought him some sort of a Martian.

Kepler's early education was desultory. He was too sickly and frail to become an agricultural laborer. The only future his family could envision for him was to enter the Lutheran ministry. As it happened, after the Dukes of Wuertemberg converted to Lutheranism, they had established a number of seminaries that could lead eventually to a state-sponsored education at the University of Tuebingen, then to the Theological Faculty and the ministry. One of the features of the seminaries was Latin. The curriculum was in Latin. Many students of Kepler's opus have remarked on the elegance of his Latin compared to his German. There is something earthy, even ungrammatical, about Kepler's German, as the letter that Applebaum turned up confirms.

From the beginning, Kepler's religious beliefs--which, along with his science were at the core of his life--were somewhat unconventional. He was a committed Lutheran but he was more tolerant of other religions than was fashionable in an age of extreme religious intolerance. Throughout his life Kepler suffered terribly for his heterodoxy. One's heart goes out to him, as time after time he is nearly destroyed because, when it came to religious principles, Kepler would not budge an inch.

In contrast, any student of Donne's life will be troubled by Donne's apostasy. Donne was born into a very distinguished Catholic family. On his mother's side there was even a connection to Sir Thomas More. Donne was, at least as a young man, proud of his ancestry and his religion. But being a Catholic at the end of the sixteenth century in England put one in mortal danger. One could be tortured to death in ways almost too unbearable to describe, especially if one was caught harboring a Jesuit or indeed any sort of Catholic priest. In 1593 Donne's brother Henry, who was a year younger, was arrested because he had had a man suspected of being a priest in his rooms. He would surely have been convicted of a felony, except that he died from the plague while awaiting trial in jail.

For an English Catholic who did not choose to emigrate--as many did--there were three choices. One could practice one's religion clandestinely, hoping not to be caught. (During the reign of Queen Elizabeth "recusants," as they were called, could practice their religion discretely, provided they also went to the Anglican service on Sundays and paid huge fines.) One could avow one's Catholicism openly and accept martyrdom, as some did. Or one could convert to the official Anglican creed. Donne did the first and then the last. When he matriculated at Oxford in 1584, his age was given as eleven. He was actually a year older, but at the age of sixteen, to obtain an Oxford degree, he would have been required to take an oath of allegiance to the Church of England. His modified age gave him an extra year at the university. As it was, he never graduated, and it is thought that he might have attended Cambridge for a few years after he left Oxford.

But John Donne was not a martyr. On the contrary, his ambition was to become part of the English establishment. By 1597, when Donne became secretary to Sir Thomas Egerton, the so-called Lord Keeper of the Great Seal (the highest honor a lawyer could then earn) who had himself converted, and who was in a position to help Donne move up the governmental ladder, Donne had become an Anglican. This must have generated a life-long agitation of his conscience. Donne's polemics against the Jesuits, who would not compromise, border on the irrational. There is something in what Dr. Johnson remarked a century later: "A convert from Popery to Protestantism gives up so much of what he has held as sacred as anything that he retains, there is so much laceration of mind in such a conversion, that it can hardly be sincere or lasting." Lasting Donne's conversion was. Sincere is another matter.

When it came to religion, Johannes Kepler's conscience was clear and his outlook tolerant. Kepler graduated from the Faculty of Arts at the University of Tuebingen at the age of twenty. He was fortunate to have had as one of his teachers Michael Maestlin, an exceedingly competent astronomer. Maestlin taught Copernican astronomy--the doctrine that the earth moved around the sun and revolved on its axis every twenty-four hours, which Copernicus had published more or less on his deathbed in 1543--in his advanced classes, which Kepler took. Kepler was grateful throughout his life for Maestlin's introduction to astronomy and, above all, to the work of Copernicus. He kept up a correspondence with his teacher, who was twenty years older than he, which Maestlin had more and more difficulty responding to.

The situation is not unfamiliar. Maestlin was very good, but Kepler was a genius. In fact, what most of us learn in our general science classes as the "Copernican system" is, as we shall see, rather far removed from what Maestlin taught Kepler--that is, far removed from what Copernicus actually did. The modifications are owing to Kepler. They represent radical departures from Copernicus's cosmology. They were too much for Maestlin. I think, incidentally, they were also too much for Donne. From the references to the New Astronomy in his poetry, it is my feeling, as I shall explain, that Donne did not really understand it in detail.

After his graduation, Kepler then matriculated at the Theological Faculty, there to begin his studies to become a Lutheran pastor. He had no thought of becoming an astronomer. His theological studies were to have ended in 1594 with his entrance into the ministry. But before that happened there occurred one of those twists of fate that seem to have been characteristic of Kepler's life and that kept propelling him toward his real destiny. The mathematics teacher at the Protestant seminary in Graz, Austria, died and, as happened frequently at the time, the seminary turned to the University of Tuebingen in Germany to find a suitable replacement. Mathematical genius is pretty difficult to hide and, as strange as Kepler may have seemed as a person, there was no doubt in anybody's mind that he was the most highly qualified individual to send to Graz. He spent the next six years there and never returned to his native Germany except as a visitor.

On July 9, 1595, while teaching a class in Graz, Kepler had an epiphany. From our point of view, it was almost entirely mad. It would hardly be worth mentioning in the present context, except that just before Donne's visit in 1619 Kepler had revisited the subject and had written a book Harmonices mundi, or Harmony of the World, which was, it appears, the main subject of conversation between the two men. A significant difference between this book and the first, A Cosmographic Mystery (1596), was that the latter contained, along with the mystical detritus, an almost casual discussion of one of Kepler's greatest astronomical discoveries: the very non-intuitive connection between the length of time it takes a planet to complete one orbit around the sun--or its period--and the average distance of the planet from the sun. This is called Kepler's Third Law, and in mathematical language it states that the ratio of the square of the period of a planet to the cube of its distance from the sun is the same for all planets. It took Newton, a half century later, to explain why it was true.

The question that Kepler posed in 1595 was in and of itself not unreasonable. He knew of six planets: Mercury, Venus, Earth, Mars, Jupiter, and Saturn. Pluto, Uranus, and Neptune had not yet been discovered. He wanted to account for the fact that there were six planets and he wanted to account for the five distances between them, which had been roughly determined by Copernicus. Kepler knew--it had been known since Euclid--that there were five so-called regular solids--solids like the cube, which is bounded by six squares, and the pyramid, which is bounded by four equilateral triangles. He knew that a sphere could be put outside each of these solids, so that all the vertices touched its surface. Similarly one can put a sphere inside each solid, so that the sphere touches all its boundaries in the center. What Kepler tried to do was to put each planet on a sphere with one of the regular solids inside it and another outside it. This bizarre scheme did not even work on its own terms. He never could fit the planet Mercury. But Kepler was smitten by it. He sent copies of his book to every astronomer he could think of.

Most important for what happened later, Kepler sent a copy to the Danish astronomer Tycho Brahe. Brahe was a great observational astronomer who had some not entirely realized theoretical ideas. He saw in Kepler, who was his junior by some twenty-five years, a mathematician of potential genius who might help him out. The two connected sooner than either of them would probably have predicted. I believe, and I am not alone in this, that if Kepler had died just after the publication of his book--always a possibility in the disease-ridden environment in which everyone then lived--he would simply have been an uninteresting historical curiosity. What made him such a great astronomer was the combination of his mystical urge to obtain ultimate laws with an absolute sense of empirical rigor. Kepler was never satisfied until whatever theory he had created fit the known facts--or at least as precisely as they were known.

In 1597 Kepler married for the first time. His wife (nee Barbara Muehleck) was at the age of twenty-three already twice a widow. She, or her family, had pretensions, and it took some negotiation before Kepler, a poor schoolmaster, was allowed to marry her. One wonders why he did, since he described her as being "simple of mind and fat of body," and worse. It does not seem to have been a very happy marriage, although it lasted fourteen years, until her death. She had borne him five children, two of whom survived. In 1613 he re-married, to Susanna Reuttinger, an orphan of twenty-four, who bore him seven children of whom, again, only two survived infancy and early childhood.

Donne's marriage, to Anne More, which took place in December of 1601, was, on the other hand, the stuff of which operas are written. When he married her she was sixteen or seventeen and Donne twenty-nine. She had been living under the protection of Sir Thomas Egerton, the very Lord Keeper whose secretary Donne then was. She was the niece of Egerton's second wife. She was the daughter of Sir George More, a very influential political figure noted for his choleric temper. Knowing that her father would not approve of the marriage--Anne was still a minor--but being very much in love, the couple married secretly, thinking, naively as it turned out, that the old man might forgive them. When he was informed in February, he went berserk. He had Donne arrested for marrying a minor and tried, unsuccessfully, to get the marriage annulled. He did succeed in getting Donne fired, and, though he was released from jail, Donne was kept away from his wife until April.

After this episode, Donne was never able to get another position with the government despite repeated attempts. He eked out a living for several years supported by patrons. King James, who seemed to take special interest in Catholic converts if they had connections such as Donne's, made it clear that it was his wish that Donne be ordained in the Anglican church. It is difficult to know Donne's real feelings about this, but in January 1615 he was ordained as deacon and priest in St. Paul's Cathedral, and the same year he was given his honorary doctorate. It is also difficult to know his feelings about his marriage. Izaak Walton, his contemporary, remarked in his biographical sketch of Donne that Donne's marriage was the "remarkable errour [sic] of his life," although he added that "God ... blest them with so mutual and cordial affections as in the midst of their sufferings made their bread and sorrow taste more pleasantly than the banquets of dull and low-spirited people." Before Anne died in August 1617, she had given birth to twelve(!) children. Five of them died either at birth or soon after. "Death be not proud ..."

There is one book of Kepler's that we can be sure that Donne read, De Stella Nova, or Of New Stars, to use its commonly shortened title, which Kepler published in 1606. We can be sure because there is a marginal note to this effect in Donne's strange tract Biathanatos, which he wrote two years later. Biathanatos is an attempt by Donne to argue that committing suicide is not necessarily a sin. Why a tract on this subject should make reference to a book on "new stars" I will explain as soon as I have explained why Kepler's book was published in Prague.

When we left Kepler he was living peacefully in Graz with his family. But increasingly the Counter-Reformation made the lives of Protestants there more and more difficult. On July 27, 1600, the Archduke Ferdinand, a Catholic who ruled Graz, published a decree that demanded that everyone in the community submit to a public examination of his or her faith in four days. If Protestants were not prepared to adopt Catholicism, they would be expelled from the city and their property confiscated. Accepting Catholicism for the sake of saving his job was something that Kepler was not prepared to do. Fortunately for him--and here is another example of his remarkable good fortune--in 1599 Brahe, after a dispute with the Danish authorities, had come to Prague. He was appointed the Imperial Mathematician--that is, official astronomer and astrologer--for the Emperor Rudolph. Kepler had visited Brahe just after his arrival and Brahe, wanting mathematical help, now arranged a position for him. Thus Kepler came to Prague.

In 1572 Brahe had witnessed the explosion of a supernova in the constellation Taurus in our galaxy. Supernovae explosions in our galaxy are rare, hence it was remarkable--again Kepler's great luck--that there was a second explosion in September 1604 in the constellation Serpentarius. By this time Brahe had been dead for three years and Kepler had succeeded him in the job of Imperial Mathematician. It was these new stars that were the subject of Kepler's book. But what was their relevance to Donne? Aristotle, and his followers among the Schoolmen, had maintained that the stars were made of a "fifth essence"--the "quinta essentia"--and not of earth, air, fire, and water. This essence was supposed to be indestructible and the stars that were made out of them immutable. But the new stars showed that stars were in fact mutable. Aristotle and his followers in the schools were simply wrong. If they were wrong about this they could be wrong about anything, including a moral question like the ethics of suicide. This is the point Donne made. He writes in his Biathanatos, " ... his [Aristotle's] Schollers stubbornly maintain his Proposition [the immutability of stars] still, though by many experiences of new Stars, the reason which moved Aristotle seems now to be utterly defeated." The New Astronomy was not merely a new science. It was a challenge to an entire moral and theological order. When Donne wrote, "'Tis all in peeces, all cohaerence gone," he meant it.

There is one piece of writing by Donne that we are sure Kepler read. In 1611 Donne published, in both Latin and English, the anonymous polemic satire that he called Ignatius, His Conclave. Ignatius of Loyola, the founder of the Society, of Jesus--the Jesuit order--had been canonized by Pope Gregory XV in 1622. The Jesuits reduced Donne to rage. In this satire Donne imagines Ignatius in hell seated next to Lucifer with whom he strikes up a companionship. This scene is witnessed by the "I" representing the author who has had "liberty to wander through all places, and to survey and reckon all the roomes, and all the volumes of the heavens, and to comprehend the situation, the dimensions, the nature, the people, and the policy, both of the swimming Ilands, the Planets, and of all those which are fixed in the firmament." But having given a bold rendering of the furniture of the universe, the narrator backs off. He remarks, "I thinke it an honester part as yet to be silent, than to do Galileo wrong by speaking of it, who of late hath summoned the other worlds, the Stars to come neerer to him, and give him an account of themselves."

The previous year Galileo, using the newly discovered telescope, had found new stars, the moons of Jupiter, and all sorts of new features on our moon. He had published a book--Siderius nuncius, or Starry Messenger--describing these discoveries that created a sensation. Donne had read the book and a year later makes reference to it. But he goes on, "Or to Keepler [sic], who (as himselfe testifies of himselfe) ever since Tycho Braches [sic] death hath received it into his care, that no new thing should be done in heaven without his knowledge." This shows that not only was Donne aware of Kepler, but he even knew that Kepler had inherited Tycho Brahe's position. But how do we know that Kepler read this? He tells us.

In 1609 Kepler wrote the first version of his science fiction novella Somnium, Sive Astronomia Lunaris--usually translated simply as The Dream. It concerns an imaginary voyage to the moon. (The cast of characters includes Fiolxhilde, the mother of the narrator. A few years later Kepler's own mother, who resembles the fictional Fiolxhilde, began her trials for witchcraft.) Like many other science fiction writers, Kepler was more concerned with describing the science of the moon than he was with the fiction. The original version of The Dream was not published but did circulate in manuscript. As we have mentioned, it has been claimed that Donne read it--Kepler, as we shall see, thought so. In 1621, two years after Donne's visit, Kepler took up the Somnium again. This time he added 223 footnotes, which actually exceeded in length the original novella.

The book was not published until 1634, or four years after Kepler's death. Footnote 8 begins, "If I am not mistaken, the author of that insolent satire called Ignatius, His Conclave, got hold of a copy of this little work of mine; for he stings me by name at the very beginning. As he goes along he brings poor Copernicus before the tribunal of Pluto. ..." The first thing that strikes one about this quotation is why is there any doubt in Kepler's mind whether the "author [Donne] of that insolent satire . . . got hold of a copy?" After all, Donne had visited Kepler just a few years earlier. Why didn't Kepler simply ask him? The answer, it seems to me, is evident. Kepler did not know that it was Donne who wrote it and Donne did not tell him. As far as I know, the first publication of Ignatius in which Donne was the acknowledged author occurred in 1652, some twenty years after the poet's death. When, in his letter--the one Applebaum turned up--Kepler described Donne's visit, no mention is made of Ignatius or indeed of anything Donne wrote. In fact, one is led to wonder if Kepler had any idea of exactly who Donne was.

It has been sometimes claimed that the fact that both Ignatius and The Dream involve voyages to the moon implies that Donne must have read Kepler before writing his polemic. I don't think so. In the first place, both men had such vivid imaginations that it is hard to understand why Donne would have needed to read Kepler to think of moon travel. He had read Galileo. That would have been inspiration enough. Besides, the two "voyages" are quite different. Kepler's travelers take an actual trip to the moon. They are carefully selected. Kepler writes, "No inactive persons are accepted into our company; no fat ones, no pleasure-loving ones, we choose only those who have spent their lives on horseback, or have shipped often to the Indies and are accustomed to subsisting on hardtack, garlic, dried fish, and such unpalatable fare. Especially suited are dried up old crones who since childhood have ridden over great stretches of the earth at night in tattered cloaks on goats or pitchforks. No Germans are suitable, but we do not despise the lean hard bodies of the Spaniards." Kepler is careful to specify the distance to be traveled--fifty thousand "German miles"--which is about the distance to the moon if one takes Kepler's definition of the German mile that he gives in one of his footnotes. He is somewhat vague on the method of propulsion. He writes: "We congregate in force and seize a man of this sort; all together lifting him from beneath, we carry him aloft." And away they go!

Donne, on the other hand, describes a potential voyage to the moon. He employs a delightful conceit inspired by Galileo's telescope. The voyager can make "new Glasses" which will "draw the Moone, like a boate floating upon the water, as neere the earth as he will." Now one can just board the "boat." But, Donne goes on to say, it will be the Jesuits who will get on the now nearby moon-ship in order to establish a "Lunatique Church" on our celestial neighbor. On the subject of the Jesuits Donne was relentless.

The "world-lines" of Donne and Kepler are now moving closer. But we still have to get Kepler to Linz from Prague and Donne to the European continent. Kepler remained in Prague from 1600 to 1612. His first few years there were the most productive of his scientific life. He transformed celestial mechanics forever. In doing so, in my view, he accomplished intellectual feats of overcoming that were comparable to what Einstein did when he created the theory of relativity. What he had to overcome was a two-thousand-year idee fixe on how celestial bodies were allowed to move. From the ancient Greeks until Kepler, the only motion allowed to these bodies was uniform and circular. Some of the early astronomer-philosophers envisioned celestial objects as being attached to crystalline spheres and some did not. But attached or not, the motions could only be uniform and circular. Unfortunately, the actual motions of the planets observed against the stars are neither uniform nor circular. In fact, the planets, from time to time, reverse their direction, something that is known as "retrograde motion."

Hence the problem posed to these savants was how to "save the appearances"--that is, how to reconcile the observed motions with the metaphysical demand that they be in "reality" uniform and circular.

In the ancient world the most complete and successful attempt to "save the appearances" was made in the second century A.D. by the Alexandrine polymath Claudius Ptolemy. In the Ptolemaic system the earth was stationary at the center of the universe. All the heavenly bodies revolved around the earth. But the motion of, say, a planet was not simply a uniform motion in a circle. There would be a sort of "guide point" that moved on a big circle. Around that the planet moved along a second, smaller circle--making a so-called epicycle. If that didn't work one could add more circles or one could displace the earth from the center. A modern scientist confronted with this scheme understands immediately why, if pushed hard enough, it will work. What is happening is that the periodic motion of the planet is being analyzed in what is called a series of harmonics. We do this all the time. We can make the series as accurate as we want by including more and more terms--by adding more epicycles. In the Ptolemaic scheme it required some thirty epicycles to reproduce the planetary motions to the degree of accuracy to which they were known.

Copernicus changed the reference point from the earth to the sun--and, indeed, added more epicycles. In fact, if you look at an actual drawing of the Copernican system as developed by Copernicus, it will be a nest of circles on top of circles. It will bear almost no resemblance to the neat diagrams of the solar system you may remember from your general science course. Tycho complicated things still further by introducing a system in which the earth was at rest while the planets circled the moving sun. It was this chimera that Kepler had been engaged to work on. Fortunately, Tycho died in October of 1601 before Kepler was forced to spend too much of his time on it--again Kepler's good luck.

Tycho and his assistants had assembled the most accurate data on the orbit of the planet Mars that had ever been taken. After Tycho's death, Kepler inherited the data and added some of his own. He also found a very ingenious way--using Mars as a reference point--to plot the orbit of the earth around the sun. This had never been done before. It turned out that the earth's motion was not uniform either. But what was the orbit of Mars or, for that matter, of any planet? After an extraordinary intellectual effort, by Easter of 1605, Kepler finally realized that it was an ellipse. You may remember from your high school geometry classes how to draw an ellipse. You take a string and tie down the ends with thumbtacks. Then you take a pencil and stretch the string and move it around a complete cycle to make your ellipse. The positions of the thumbtacks are called the "foci" of the ellipse. If you make the foci coincide, then you have a circle, so that, in a sense, the ellipse is the simplest generalization of the circle. In Kepler's system--our system--the sun is at one of the foci of the orbital ellipse. Hence, not only is the earth displaced from its central position, but the sun is not even at the center.

One is awed by the sheer force of the intellectual work that Kepler did. He had no computing machines. All the arithmetic was done by hand--hundreds of pages that still survive. He did not even have the mathematics he needed: the differential and integral calculus that would be developed later in the century by Newton and Leibniz. But, when he needed them, he invented approximation methods to a calculus that he did not even know existed. Kepler had a correct intuition about how the whole mechanism worked. He thought that it must be due to a force that emanates from the sun. The planets move more rapidly when they are close to the sun since, Kepler reasoned, they are subjected to a greater force. Magnetism was then being studied, so he thought that it might be magnetism. It isn't. What it is, as Newton pointed out, is gravity.

But it was Kepler who first understood that the motion around the planetary orbits was not uniform. Nonetheless, he discovered a remarkable regularity. If you draw a line to the planet from the sun, then in equal amounts of time the line to the planet, despite the non-uniformity of the motion, will sweep out equal areas. These two discoveries along with the relation he found a decade later between the lengths of planetary periods and their distances from the sun are known as Kepler's Three Laws. They were empirical discoveries but guided by Kepler's intuition and his insistence that the planets should have the same physics as our own. It took the genius of Newton to show how they could be derived directly from the dynamics of gravitation.

Kepler put his elliptical discoveries into a book--Astronomia nova, to give its abbreviated Latin title--The New Astronomy, which he finally published in 1609. It can rightly be called the first truly modern astronomy book. I do not think Donne could have understood much of it, if he read it, which I also doubt. It is one thing to have a realization of the general implications of changing the locus of the solar system from the earth to the sun, or of discovering "new stars"; but it is quite another to understand the sort of thing that Kepler did in The New Astronomy. Let me give a specific example from Donne's poetry that shows that he really did not understand in detail what had happened. My example is taken from the poem "A Valediction: Forbidding Mourning," which some Donne scholars think was written in 1611. The verse in question reads,

Moving of th'earth brings harmes and feares,
Men reckon what it did and meant,
But trepidation of the spheares,
Though greater farre, is innocent.

In the third line the use of "trepidation" resonates with "harmes and feares." But the rest of the line and the next show that Donne knew the astronomical usage of the term then current. The apparent motion of the sun, as measured in relation to the stars, is also not regular. At the equinoxes the sun reverses its direction. But the astronomers, up to and including Copernicus, claimed that at the equinoxes there was an additional solar motion--a kind of oscillation that was called trepidation. The pre-Copernican astronomers, who believed that the stars were attached to giant celestial spheres, accounted for this by a "trepidation of the spheares"--a motion that one might think of as "innocent" since the spheres were made of the special celestial material. But Copernicus accounted for all the apparent motions of the sun against the stars by the earth's rotation about the sun and the revolution of the earth on its axis. There was in his system no "trepidation of the spheares" but rather a trepidation of the earth.

Donne has missed this very essential difference. It is much less surprising that he missed Brahe's discovery that there is no such thing as trepidation. The earlier astronomers had simply been wrong. There is nothing to account for, although, despite Brahe's measurements that Kepler must have known about, Kepler still kept some slight irregularity in his analysis of the sun's motion. But this, too, would have been accounted for by a trepidation of the earth. It is said that this poem was written for Donne's wife before he left for France on an earlier trip. "No tear floods, nor sigh-tempests move," he tells her.

Kepler's position in Prague was viable only so long as the Emperor Rudolph remained in power. But Rudolph showed increasing signs of mental instability and was forced to abdicate in 1611. His brother Matthias succeeded him the following year. With the abdication of Rudolph, Kepler began looking for a more secure position. In 1612 he accepted one in Linz as the district mathematician and teacher in the district school. This was not a position with the distinction Kepler deserved, but he accepted it because he thought that his wife, who never liked Prague, might be happier there. But before she could make the move, she died of typhus. Kepler remained in Linz, the capital of Upper Austria, until 1626, the longest he had ever lived in any single place. Now we have gotten Kepler to Linz.

It remains to get Donne to the Continent. Rather than attempt anything like a full accounting of the political and religious history that led up to the 1619 diplomatic mission on which Donne served, I will begin with King James I of England and his two surviving children, Princess Elizabeth and her younger brother Prince Charles. By the epoch we are considering, the rest of the King's offspring had died. King James, it may be recalled, was the son of Mary, Queen of Scots. This remarkable woman, who had been forced to abdicate in favor of her infant son, was imprisoned in England and was finally executed in 1578. When Queen Elizabeth I died in 1603 with no progeny of her own, James, who had been ruling Scotland as James VI, became James I of England. In the meanwhile he had married Princess Anne of Denmark. One of the marriage ceremonies in 1589 was performed in Copenhagen. It was the King's only trip to the Continent, and while there, among other things, he visited Tycho Brahe's observatory. The mother of his bride, Sophia of Mecklenburg, the then queen mother of Denmark, was one of Tycho's patrons. As far as I can tell, this was King James's only venture into astronomy. He was presented with a signed copy of Kepler's book on the new stars. It is not clear that he ever read it.

This was an era when royal marriages were moves in a diplomatic chess game. When it came time for Princess Elizabeth and Prince Charles to marry, the choice of their mates depended a great deal on what ends the King wanted them to serve. It was Princess Elizabeth's turn first. After some back and forth with other suitors, she was betrothed in 1613 to Frederick V, the Protestant Elector Palatine of the Rhine. In 1619, after the death of Emperor Rudolph's brother Matthias, Frederick served briefly as the King of Bohemia, until he was deposed in 1620 by a Catholic army of Spaniards and Bavarians. He was sent into exile and died in obscurity in Germany. It was Frederick who was supposed to have protected the interests of Protestants in central Europe--a matter of concern to King James, who was mindful of the well-being of his daughter.

King James was not exactly noted for his physical courage. At meetings of his court in England he wore a stiletto-proof vest. The King abhorred violence and, in particular, war. One of King James's notions for avoiding a war with Catholic Spain was to try to marry Charles off to a Spanish princess: the Infanta Maria, daughter of Philip III. James also wanted the Spanish monarch's help in restoring his son-in-law's position in Bohemia. The marriage never came to pass, much to the relief of most of the British people, who did not want their future king to marry a Catholic. He did, anyway, when in 1624 he signed a marriage treaty with Henrietta Maria, the daughter of Henry IV of France. King James died in 1625, and not long afterwards Charles began warring with Spain. But in 1618, when the eruption of violence between Catholics and Protestants occurred in Bohemia, bringing with it a possible intervention from Spain, King James decided that he might be in a position to mediate between the feuding factions. To this end he contacted the King of Spain with an offer to make peace. The King of Spain, in turn, sought the advice of his ex-ambassador to England, the Conde de Gondomar, who replied with considerable candor:

The vanity of the present King of England is so great that he will always think it of great importance that peace should be made by his means, so that his authority may be increased ... [nonetheless] it is possible and fitting to accept this mediation, since it cannot do any harm, or make things worse than they would be without it. ... [T]he King of England should send immediately to Germany an ambassador to treat about it.

Thus the diplomatic mission on which Donne was to serve was born.

To lead what turned out to be an exercise in futility, the King chose

James Hay--Lord Doncaster. One historian writes that Doncaster was

a handsome Scot who by virtue of James I's susceptibility to young males, became one of the leading figures in the court and was created successively Viscount Doncaster and Earl of Carlisle. Hay was best known for his facility in spending large sums of money, and under his guidance the vulgar excess which characterized Jacobean court entertainment reached a new height. A feast which he gave for the French ambassador at Essex House comprised sixteen hundred dishes which it took a hundred cooks eight days to prepare.

Whatever enthusiasm Doncaster might have had for this mission was tempered by the fact that, as the Queen had died in 1619, the entourage was required to wear mourning clothes. Donne had even less enthusiasm. His wife had died in 1617, leaving the surviving children in his care. He felt that he was deserting them. For some reason, Donne decided that he would never return alive from this trip. He wrote letters and preached sermons in the tone of a man condemned. He also announced that he would not be writing letters back to his friends in England. Hence we do not seem to have any record by Donne of his meeting with Kepler. Nonetheless the two men were, Donne above all, in no position to refuse a royal command. Despite the mourning clothes, the mission was an extravagant one. It took more than twenty-five coaches for its ceremonial entry into Brussels. (Ultimately the mission cost about £ 30,000--the equivalent of $2 million in present currency.) There were lords and knights, a physician and cooks, and, of course, John Donne, who was its chaplain. It meandered its way for some six months until it reached Linz on October 23. From Kepler's letter, which I am about to present, we can't tell who actually came to visit him--Donne alone, or Doncaster and some of his entourage. I would speculate that it was Donne alone. Nothing I have read about Doncaster leads me to believe that he would have had any interest in meeting Johannes Kepler. Furthermore, as far as I can tell, Kepler had no facility in Linz for entertaining such a group. In fact, the letter suggests that Kepler had only seen Doncaster in town from a distance. I would suppose that Kepler and Donne spoke Latin. There is no reason to believe that Kepler knew English or Donne knew German. Until I read the letter, I had hoped that the meeting might have been an epiphany--one of those occasions that changes the destiny of the participants forever. As you will see, it does not seem to have been. Here is the letter in translation. It is addressed to a woman. The German is somewhat rough-hewn and in places not entirely clear. I have chosen what I think are the most plausible interpretations. (I am very grateful to Gerald Holton and Freeman Dyson for their help in translating this letter.)

Noble, much-honorable, virtuous, honorably-beloved sister in law [This is very likely a form of address and not literally a reference to Kepler's sister-in-law. This sort of address must not have been uncommon. When late in life Donne wrote some of his most personal letters to his friend Anne Cokayne, he addressed her as "my noble dear sister"]: I received your letter and report from England a month ago. From it I gathered your and your honorable cousin Burlemachi's favorable efforts and diligence in presenting my work.

The work in question is certainly Kepler's Harmony of the World, which he had published in the summer of 1619. His intent was to dedicate the book to King James, in part as a recognition of his role as a peacemaker. Kepler was, no doubt, aware as well that the King's son-in-law Frederick was the protector of the Protestants in Bohemia. But the sheet with the dedication was not delivered until early in 1620--after Donne's visit. By this time, Frederick was in serious trouble and many of the printed copies do not have the dedication.

The letter goes on,

And because I now also reply confidently on the continuation of this promotion, I cannot help reporting again (perhaps my last letter did not get through) that I have talked with a Doctor of Theology named Donne, who was travelling with His Royal Majesty's envoy, Mr. Doncastre [sic], and appeared here on October 23, [This would seem to imply that there was another letter dealing with the meeting which may not have been preserved.] I told him that I had ordered the dedication copies [presumably the copies of Harmony of the World dedicated to King James], and added that, because I had seen the envoy [Doncaster] here [in Linz], I wanted to ask his Grace to convey and commend the work. Because one could sense that this wish was well-received, and because Mr. D. Donne [sic] thought that the envoy would return to court before the presentation [of the dedication] copies, and since this promised every beneficial promotion, I wrote on his advice, a letter in French to Mr. Burleranchi [sic][a] and gave it to the doctor. In this letter I informed him [Burlemachi] about all this and, in case the presentation [to the King] had not happened yet, asked him to take note of Mr. D. Donne's and the envoy's opinion about it.

But because I have now learned that the envoy will arrive long after the presentation of the work [In fact, the mission did not return to London until January.] I am concerned that my earlier letter might keep Mr. Burlemachi from promoting this work. And because my gracious sister-in-law might have some thoughts about this [promoting my work] I would ask you in the meantime to write letters supporting it, still showing respect to the envoy so that what you do would not be interpreted as fickleness on my part. [I have not translated the last paragraph of the letter, which has to do with the financial aspects of printing the book.]

It seems to me clear from this letter, and from what has gone before, that as far as Kepler was concerned Donne was an appendage to the British mission who could be useful in promoting Kepler's work in England. Of the "Jack Donne" who wrote some of the greatest poetry in the English language he knew nothing--and still less of the Donne who wrote Ignatius or who preached upon the tolling of the bell. A year later Sir Henry Wotton, who had been with Donne as a student at Oxford and remained one of his closest friends throughout his life, visited Kepler in Linz. Wotton, who had had a long career as a diplomat in Venice, was temporarily functioning as King James's envoy in Middle Europe. Some years earlier. Wotton had been in serious difficulties with the King because, as a joke, he had written, in an album of remembrances belonging to a German friend, "An Ambassador is an honest man, sent to lie abroad for the good of his country." Somehow the King learned of this and was not pleased. In time, Wotton was forgiven and in 1620 came to Linz to suggest that Kepler might consider relocating in England.

My guess is that during his conversation with Donne, Kepler must have conveyed some of his unhappiness in Linz. From the time he arrived he found himself in conflict with the orthodox Lutherans in the community and was even denied communion. In 1616, there was an attempt to eliminate his job altogether. Nonetheless, when it came to relocating abroad, Kepler could not make himself do it. He stayed in Linz until 1626, when the flames of war literally consumed the city. From that time until his death in 1630, he found no tranquil place where he could do his work.

Johannes Kepler died in Regensburg, Germany, on November 15, 1630. He was buried in the churchyard in front of Peter's Gate. The grave and the churchyard were swept away in the course of the Thirty Years' War. John Donne died some six months later, on March 31, 1631. He was buried in St. Paul's Cathedral. A statue in effigy was carved to mark his resting place. Of it his friend Sir Henry Wotton remarked, "It seems to breathe faintly; and, Posterity shall look upon it as a kind of artificial Miracle.

a Professor Applebaum has informed me that "Burleranchi" or "Burlemachi" was a gentleman whose actual name seems to have been Burlemaqui. He was of Italian-Protestant descent but had been naturalized English. He seems to have been a somewhat shady "wheeler-dealer"--he was once fined £10,000 by the Star Chamber--but was used by the Crown in some of its international financial dealings. Kepler appeared to believe that Burlemaqui might be an entre to the King.

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By JEREMY BERNSTEIN

JEREMY BERNSTEIN is the author of several books, including Cranks, Quarks, and the Cosmos, The Uranium Club, and, most recently, A Theory for Everything. Grateful acknowledgment is made to Wilbur Applebaum, Cathryn Carson, Denis Donoghue, Freeman Dyson, Owen Gingerich, and Gerald Holton for their generous help in the preparation of this article.