Kepler wanted to avoid Tycho as much as he could, and he spent many more months away from him than in his company. That summer he went again to Graz to settle his family affairs, but he was expelled in early August without further reprieve. Tycho once more implored him to return, and when he did so, everything had changed, for Emperor Rudolf had expressed the wish that Tycho work closer to the imperial residence. Tycho dutifully moved his entire establishment to Prague, first at a noisy tavern at the Nový Svêt, and by mid-February 1601 to the vice-chancellor’s house, which the emperor bought for him; Kepler was supposed to live there too. In the meantime, the instruments had arrived and were put in the loggias of Queen Anne’s summer castle, now to be an observatory. Kepler, who with his family moved in with Tycho’s clan, promptly had a nervous breakdown and a few psychosomatic complications as well; recuperating, he made another trip to Graz (his wife’s father had converted to Catholicism to save the family real estate), but when he returned to Prague there was not much time left for shared studies and observations. On October 13, 1601, Tycho Brahe was brought home in agony from a banquet at the town house of Petr Vok of Rožmberk. It was rumored that his bladder had burst because he did not want to leave the table before the host, and Kepler confirmed in his notes that the rumors were not far off the mark: Tycho held back his water beyond the demands of courtesy and “put politeness before his death”; when “he got home he was scarcely able to urinate.” Tycho was delirious for five nights with his uremia, and died on October 24, after he had composed his last words in flawless Latin:
ne frustra vixisse videar
(“let me not seem to have lived in vain”). He was buried, with pomp and circumstance, at the Týn Church, and a few days later Kepler was notified that he was appointed mathematician to his imperial majesty. He could not bear Tycho Brahe while he was alive, but he remained loyal to him and to his research for the rest of his life.
Emperor Rudolf granted his new court mathematician privileged access
to all of Tycho’s papers and instruments, but Tycho’s family energetically staked out its own claims, especially the son-in-law, who sensed the financial possibilities. Kepler had to litigate and, often, to compromise. He had hoped that his salary would be equal or close to that of Tycho, but he had to do with less than a third, the exchequer was always in arrears, and the
mathematicus
was desperate for cash. The Keplers did not live in palatial splendor; after Tycho died, they moved to dwellings close to the New Town cattle market, definitely not a good address, and Kepler rightly complained of having to spend an hour walking to Hrad
any Castle. He later resided, possibly free of charge, in a university college at Ovocný Trh (Fruit Market) and, ultimately, in the Old Town in the Karlova Ulice close to the entrance to Charles’s stone bridge.
Kepler did not neglect his aristocratic connections, occasionally even condescending to deliver a horoscope, and made friends among Czech scientists and instrument makers who had been attracted to Prague. He probably did not have any opportunity to work with Tadeáš Hájek, who had died in 1600, but Martin Bachá
ek, rector of the Carolinum, and the physician Jessenius, who were involved in a tardy university reform, both sought his friendship and advice; he also knew Václav Budova of Budovec, political chief of the Czech Brethren in the Estates, who had traveled widely in the Near East and written a number of astronomical essays. Among other members of the Prague scientific community close to Kepler was the Swiss Jost Bürgi, who studied techniques of mathematical computation and early compiled tables of logarithms—unfortunately Lord Napier published his in 1614, six years before Bürgi followed with his own in Prague. Kepler was less happy with Galileo Galilei, whom he deeply admired. He had endorsed his telescopic discoveries enthusiastically and sight unseen, but when he implored him to let him work with one of his telescopes, Galileo did not answer his request; Kepler had to turn to the visiting elector of Cologne, who had received one from Galilei, and was allowed, at least from August 3 to September 9, 1610, to use the elector’s instrument. (Twentieth-century admirers of Galileo who take their information from Bertolt Brecht’s play might do well to read Arthur Koestler, who closely analyzed Galileo and Kepler’s relationship in solid and devastating detail.)
Kepler’s twelve years in Prague may have had their financial problems, but they were the most productive years of his life, and the emperor could well have been satisfied with a court mathematician, driven by an appetite for constant work, who published thirty treatises. It is possible that, in Prague, Kepler, who considered himself Tycho’s heir, put off at
least for a time his Pythagorean visions about the harmony of the universe (he was to return to them when he moved to prosaic Linz, in Upper Austria) and followed, more intensely than in his early and later years, the essential necessity to observe and to calculate rather than to dream; his Prague research about physical astronomy and the fundamentals of optics contributed more substantially to the development of modern sciences than to a magical vision of the universe. In Prague, he articulated two of his planetary laws—about the planets traveling in elliptical orbits and about the variations of their speed—and by asking questions about the cause of their movement made astronomy the physicist’s realm, preparing the way for Sir Isaac Newton’s universal laws of gravity.
Tycho Brahe and Galileo Galilei had used their instruments without systematic study of their efficiency, and Kepler, perhaps because he was born with impaired eyesight, was the first to develop a theory about the rays of light, the workings of refraction, and the function of the human eye; informed by his Prague colleague Jessenius about human anatomy, he sensed the structure of optical nerves. In a world in which astronomers sold horoscopes as a matter of course, Kepler declined, as early as 1601, to be an astrologer of the traditional kind who ascribed to planets an unmediated influence on man’s fortune, though he still believed that planetary aspects molded the human condition. Kepler did not want to get involved, and when he was asked by intermediaries to advise the emperor, he distinctly refused and insisted that “astrology should be kept away from the emperor’s mind.” It was the tragedy of Kepler the scientist that he had to accept employment late in life by General Wallenstein, who was not at all interested in scientific observation but eager only to enjoy prophecies of future victories.
The physician Johannes Jessenius de Magna Jessen has a special place among the scientists who, in difficult times, wanted to restore the ancient excellence of Prague’s Carolinum. He was a true Renaissance scholar, whom Czechs as well as Slovaks counted among their own, for more or less legitimate reasons. Jessenius came from a middle-class family originally in central Slovakia (then part of Hungary), but he was born (in 1566) in Silesian Breslau, where his father owned a tavern and married a local Silesian woman. In various university documents, the student was said to belong to the Polish “nation,” being a Silesian by birth, or, in Italy, to the “natio Germanorum”; often, when it was a matter of prestige, he called himself a “Hungarian knight” (so much for Mitteleuropa). Jessenius pursued his early philosophical and medical studies at Wittenberg and
Padua, where he received his doctorate in 1591 after defending a thesis on afflictions of the gallbladder; being well trained and highly ambitious, he returned to Wittenberg as professor of anatomy and became rector of the university later. He too felt attracted to imperial Prague (though the nearly dormant university had little to offer); after placing his bets well by entertaining Typotius, the imperial court historiographer, and Tycho Brahe, in mid-June 1600 at the Carolinum he publicly dissected a male corpse delivered to him from the gallows. This was not the first Prague dissection but certainly the most formal and festive one, judging from the serried ranks of dignitaries and fashionable people who attended his performance, in which he proceeded, according to tradition, from the abdomen to the brain, occasionally praising the cool weather which fortunately diminished the stench of the rotting flesh.
Jessenius described this feat in a longish Latin treatise which includes a marvelous Baroque dedication to nearly everybody who could be helpful in Prague. It includes a few hexameters in praise of Bohemia and the emperor, and a few pages of glowing praise of Prague, not only a city but “a world.” The emperor promptly requested the prince-elector of Saxony to let Jessenius come to Prague, but he stayed there only for six years (1602-8). He may have felt frustrated because the university did not offer sufficient possibilities for all his talents or because he felt uneasy about the distinct predominance of the Catholic faction at court. He transferred to Vienna to serve Matthias, Rudolf’s brother, perhaps feeling more at ease with a protector who, at that time, was supported by the Protestant Hungarian and Bohemian Estates. Jessenius published a good deal, both in Prague and in Vienna, especially on anatomy and the blood vessels, and when in 1617 he was offered the rectorship of the Carolinum he readily accepted and returned to Prague. He was deeply involved in the rebellion of 1618 and the conflicts between the Prague Estates and Vienna, as both university rector and diplomat seeking international support for the rebels, and he was the prominent academic among those executed in the Old Town Square in 1621. Nearly three hundred years later the Prague physician Jan Jesenský (father of Milena, dearly beloved by Franz Kafka), a Czech nationalist and pioneer stomatologist, proudly derived his ancestry from Jessenius, and I do not know whether he was aware that his Baroque forebear had done excellent work in stomatology too.
To separate the scientists at the imperial court from the alchemists who flocked to Prague is to use anachronistic norms to define two distinct groups which, to their contemporaries, probably were but one. Some of them preferred systematic observation of natural phenomena while others, strongly believing in the unity of all creation and the necessary correspondences among its constituent parts, experimented with the transmutation of elements or, in the service of the great and the wealthy, hoped to make gold, silver, and precious stones, or to distill a few gulps of
aurum potabile,
fluid and drinkable gold that was said to guarantee eternal youth. Astrology was just beginning to be disreputable to professional astronomers, and the dividing line between chemistry and alchemy was uncertain and diffuse; in Prague—at the court, in the Minor Town, and downtown—there lived as many scientists trying to emancipate solid knowledge from vague Egyptian and Alexandrine traditions as traveling charlatans who, quoting secondhand Trithemius or Agrippa, tried to sell their tricks to the highest bidder, whether the emperor or somebody else. Learned court physicians, among them Tadeáš Hájek and Michael Maier, who had strong interests in pharmacology and chemistry, were not averse to studying the traditional texts of alchemy, but they usually kept apart from the self-assured amateurs, con men, and swindlers who appeared from nowhere, sought the protection of the court, the barons, or gullible rich patricians in the Old Town, took the money, and ran, if they could. Emperor Rudolf, extolled by his admirers as the second Hermes Trismegistos (the magical Egyptian king who had writ the secret of alchemy on sapphire), was rather lenient to the traveling alchemists. Under pressure from the law courts, he occasionally imprisoned an alchemist for debts or banned him from the country (unless a powerful baron intervened), but he never had one executed, as was the habit of the German princes beyond the Bohemian borders. Philipp Jakob Güstenhofer, after some éclat in Prague, was hanged in Saxony; the false Greek count Marko Bragadino, who had astonished Prague citizens while walking with his devilish black hounds at his side, was executed in Munich, clad in an elegant suit adorned with false gold; and the evil Italian Alessandro Scotta, first a great sensation in Prague but later forced to show his art in a little wooden booth in the Old Town Square, on his further journey by less than magic means impregnated the duchess of Coburg, who craved a child, and he would have been killed if he had not succeeded in disappearing. The
unfortunate woman was sentenced to life in a nunnery and died twenty years later.
The most famous, or infamous, purveyors of the occult arts appearing in Prague in the early 1580s were John Dee and Edward Kelley, two Englishmen who offered their services to the emperor and to powerful nobles. Prague contemporaries and later Czech historians took a dim view of that traveling pair (not entirely undeserved), but a spate of recent studies about Dee has clearly shown that the two radically differed in character, learning, and attitude, to say the least: the scholarly and earnest John Dee was “a unique intellectual force in Elizabethan England,” Peter J. French has argued, and Edward Kelley an imaginative fraud with a criminal record and a lusty eye for profits of all kinds. It is impossible to say with any certainty why Dee, a scholar of high achievements and independence of thought, for many years joined his and his family’s life to that of Kelley, an unscrupulous adventurer of the occult; in his thirst for knowledge he may have really believed that Kelley, and nobody else, was capable of understanding the pure language of Adam and would translate to him what the angels said in long magical seances. From 1582, when Kelley first appeared in Dee’s study, they traveled and worked together in Poland, Bohemia, and Germany, and parted ways only in 1589 in Prague, when Dee, upon Queen Elizabeth’s request, returned to England and Kelley preferred to stay on in Bohemia. Dee died in utter penury in England, forced to sell his books one by one, and Kelley came to a bad and bitter end in Bohemia.
John Dee (born in 1527), son of a vintner who may have been employed in a minor function at the court of King Henry VIII, was early seized by an intense longing for universal knowledge; at St. John’s College, Cambridge, he studied for eighteen hours a day, he said, and was among the original fellows of Trinity College. He traveled twice to Louvain to take up mathematical and cartographic studies, lectured on Euclid in Paris, but turned down academic appointments because he wanted to be left to his independent work. His religious principles came under suspicion early; when he suggested to Queen Mary that a royal depository of books and ancient manuscripts be established, there was no official response; he then built his own library, which became one of the most famous in Elizabethan England, at his home at Mortlake, on the banks of the Thames River in Surrey. Queen Elizabeth favored his services and consulted him about naval affairs and her toothaches; he was invited to Richmond to see the queen, who, in turn, visited with all her official retinue at his Mortlake home. He had concentrated on mathematics as
informing all creation, but in the early seventies, dissatisfied with the rhetorical canon of the universities, he shifted his interests to the occult meaning of numbers and, by 1581, held his first séance, trying with the help of a “skryer,” or translator, to bring down the angels to his study and to understand what they said; unlike Faust, who tried in vain to force the restive
Erdgeist
to speak up, Dee believed the angels were ready to talk if only confronted with a translator of unusual gifts. Unfortunately, on March 10, 1582, a young man appeared at Mortlake, trying to convince Dee that he was heir to occult knowledge and formulae, saved from a bishop’s grave (desecrated by iconoclasts); the visitor quickly succeeded beyond his wildest dreams. It was Edward Kelley, or Talbot, a trained apothecary’s apprentice, who had briefly gone to Oxford, worked for a time as a scribe, falsified official documents, and been punished by the Lancashire authorities, who cut his ears off (he wore his hair long or had a black cap with flaps to give him a scholarly appearance). Dee had found his disreputable Mephisto.
It may have been Kelley’s idea to go to Eastern Europe to sell occult knowledge for profit and preferments; in any case, on the invitation of a Polish nobleman close to the Polish Hapsburg party, they first went to Cracow, then on to Prague, the new Mecca of alchemists. It was the influential Spanish ambassador Guillén de San Clemente who arranged for an audience with the emperor, not an easy feat, but the meeting, on September 3, 1584, was not a success, possibly because Dee, too self-assured, indulged in prophecies of a new age and the defeat of the Turks if only Rudolf would mend his sinful ways; even a subsequent letter addressed to the emperor hinting at the success of occult experimentation and the transmutation of metals did not entirely convince Rudolf, who appointed a senior secretary to find out more about the English visitor. Dee was quick to endear himself to the emperor’s trusted physician, Hájek, but papal diplomats persuaded the court to expel the English gentlemen from Prague and Bohemia; the emperor signed the required mandate.
Dee and Kelley were saved from further wanderings in Germany and elsewhere by the southern Bohemian Vilém of Rožmberk, who protected them at his residence of T
ebo
, where they went on with their experiments. The foreign correspondents watching from Prague were astonished at the monies Vilém of Rožmberk invested, and wild rumors circulated about Dee’s crystal ball and his famous black mirror, made of a polished stone brought from Aztec Mexico, with which he claimed to look into the future (the crystal ball and the mirror are loyally preserved at the British Museum). However, Dee and Kelley began to fight, as Kelley did not want
to go on translating angelic messages, all in numerical code. Dee could not do without him, and he finally submitted to Kelley’s blackmail and signed a formal statement, on May 3, 1587, declaring that they would own everything in common, as the angels required of them, including their wives. Fortunately, Queen Elizabeth requested Dee’s return to England, and he left Bohemia, where his intellectual importance has never been recognized.
After the departure of Dee, Kelley (totally unburdened by scholarly seriousness) dominated occult studies both in Rožmberk’s T
ebo
and in Rudolf’s Prague, and went, at least for a while, from success to success. He seems to have convinced his protectors of the efficacy of his tinctures, acquired Bohemian citizenship, and was knighted by the emperor, accepting the title “de Imany,” referring to his alleged distant Irish forebears. He married a rich and well-educated Czech woman who gave him, apart from her opulent dowry, a daughter and a son; soon his brother arrived from England and married a rich Czech girl too. From his Rožmberk protector Kelley received, in 1590, the burgh of Libe
ice, the estate of Nová Libe
, and about nine villages, peasants included; from his Czech dowry he bought a brewery, a mill, and a dozen houses at Jílové, well known for its gold mining, and two stately houses in the New Town of Prague, one of them not far from the Monastery of the Slavs. The home was famous in Prague as “Faust’s house”—though Faust never resided there. Kelley did, and later, in the enlightened eighteenth century, the home was owned by Mladota of Solopisky, the last Czech alchemist.