The Reformation

by Will Durant

  Into this resigned old age burst, in 1539, an enthusiastic young mathematician, Georg Rheticus. He was twenty-five, a Protestant, a protégé of Melanchthon, and a professor at Wittenberg. He had read the Commentariolus, he was convinced of its truth, he longed to help the old astronomer who, far off in an obscure Baltic outpost of civilization, was waiting so patiently for others to see, with him, the invisible rotation and revolution of the earth. The youth fell in love with Copernicus, called him “the best and greatest of men,” and was deeply impressed by his devotion to science. For ten weeks Rheticus studied the big manuscript. He urged its publication. Copernicus refused, but agreed to have Rheticus publish a simplified analysis of its first four books. So in 1540 at Danzig the young scholar issued his Narratio prima de libris revolutionum—First Account of the Books of the Revolutions of the celestial bodies. He sent a copy hopefully to Melanchthon. The kindly theologian was not convinced. When Rheticus returned to Wittenberg (early in 1540), and commended the Copernican hypothesis in his class, he was “ordered,” he says, to lecture instead on the Sphaera of Johannes de Sacrobosco.39 On October 16, 1541, Melanchthon wrote to a friend: “Some think it a distinguished achievement to construct such a crazy thing as that Prussian astronomer who moves the earth and fixes the sun. Verily, wise rulers should tame the unrestraint of men’s minds.”40

  In the summer of 1540 Rheticus went back to Frauenburg, and stayed till September 1541. Repeatedly he begged his master to give his own text to the world. When two prominent clergymen joined in the appeal, Copernicus, perhaps feeling that he had now one foot safely in the grave, yielded. He made some final additions to the manuscript, and allowed Rheticus to send it to a printer in Nuremberg, who assumed all financial costs and risks (1542). As Rheticus had now left Wittenberg to teach in Leipzig, he delegated to his friend Andreas Osiander, a Lutheran minister at Nuremberg, the task of seeing the book through the press.

  Osiander had already written to Copernicus (October 20, 1541) suggesting that the new view should be presented as an hypothesis rather than as proved truth, and in a letter of the same day to Rheticus he had pointed out that by this procedure “the Aristotelians and the theologians will easily let themselves be appeased.”41 Copernicus himself had repeatedly termed his theories hypotheses, not only in the Commentariolus but in his major text;42 at the same time his Dedication claimed that he had supported his views with “the most transparent proofs.” We do not know how he answered Osiander. In any case Osiander, without appending his own name, prefaced the book as follows:

  To the reader, concerning the hypotheses of this work.

  Many scientists, in view of the already widespread reputation of these new hypotheses, will doubtless be greatly shocked by the theories of this book.... . However .... the master’s .... hypotheses are not necessarily true; they need not even be probable. It is completely sufficient if they lead to a computation that is in accordance with the astronomical observations.... . The astronomer will most readily follow those hypotheses which are most easily understood. The philosopher will perhaps demand greater probability; but neither of the two will be able to discover anything certain .. . unless it has been made known to him by divine revelations. Therefore let us grant that the following new hypotheses take their place beside the old ones which are not any more probable. Moreover, these are really admirable and easy to grasp, and in addition we shall find here a great treasure of the most learned observations. For the rest let no one expect certainty from astronomy as regards hypotheses. It cannot give this certainty. He who takes everything that is worked out for other purposes, as truth, would leave this science probably more ignorant than when he came to it....43

  This preface has often been condemned as an insolent interpolation.44 Copernicus may have resented it, for the old man, having lived with his theory for thirty years, had come to feel it as part of his life and blood, and as a description of the actual facts of the universe. But Osiander’s preface was judicious and just; it reduced the natural resistance of many minds to a disturbing and revolutionary idea, and it is still a good reminder that our descriptions of the universe are the fallible pronouncements of drops of water about the sea, and are likely to be rejected or corrected in their turn.

  The book appeared at last, in the spring of 1543, with the title, Nicolai Copernici revolutionum liber primus (First Book of Revolutions); later the book came to be known as De revolutionibus orbium coelestium (On the Revolutions of the Celestial Orbs). One of the first copies reached Copernicus May 24, 1543. He was on his deathbed. He read the title page, smiled, and in the same hour died.

  The Dedication to Pope Paul III was itself an effort to disarm resistance to a theory which, as Copernicus well knew, flagrantly contradicted the letter of Scripture. He began with pious assurances: “I still believe that we must avoid theories altogether foreign to orthodoxy.” He had long hesitated to publish, wondering “were it not better to follow the example of the Pythagoreans .... who were accustomed to transmit the secrets of philosophy not in writing but orally, and only to their relatives and friends.” But learned churchmen—Nicholas Schonberg, Cardinal of Capua, and Tiedeman Giese, Bishop of Kulm—had urgently recommended that he should publish his findings. (Copernicus felt it wise not to mention the Lutheran Rheticus.) He acknowledged his debt to Greek astronomers, but, by a slip of the pen, he omitted Aristarchus. He believed that astronomers were in need of a better theory than the Ptolemaic, for they now found many difficulties in the geocentric view, and were unable to calculate accurately, on that basis, the length of the year. And he appealed to the Pope, as a man “eminent... in the love of all learning, and even of mathematics,” to protect him against the “bites of slanderers” who, without adequate mathematical knowledge, would “assume the right to pass judgment on these things,” or would “attack this theory of mine because of some passage of Scripture....“45

  The exposition begins with postulates: first, that the universe is spherical; second, that the earth is spherical—for matter, left to itself, gravitates toward a center, and therefore arranges itself into a spherical form; and third, that the motions of the celestial bodies are uniform circular motions, or are composed of such motions—for the circle is the “most perfect form,” and “the intellect shrinks with horror” from the supposition that the celestial motions are not uniform. (Reason in thought would be impossible unless there were reason in the behavior of the objects of thought.)

  Copernicus notes the relativity of motion: “All change in position which is seen is due to motion either of the observer or of the thing looked at, or to changes in the position of both, provided that these are different. For when things are moved equally relatively to the same things, no motion is perceived as between the object seen and the observer.” 46 So the apparent daily rotation of the planets about the earth could be explained as due to a daily rotation of the earth on its axis; and the apparent annual movement of the sun around the earth can be explained by supposing the earth to move annually around the sun.

  Copernicus anticipates objections. Ptolemy had argued that the clouds and surface objects of a rotating earth would fly off and be left behind. Copernicus answers that this objection would hold still more against the revolution of the major planets around the earth, since their great distances would imply vast orbits and extreme speeds. Ptolemy had further held that an object propelled directly upward from a rotating earth would not fall back to its point of origin. Copernicus replies that such objects, like the clouds, are “parts of the earth,” and are carried along with it. And to the objection that the annual revolution of the earth around the sun should manifest itself in a movement of the “fixed” stars (stars beyond our planetary system) as observed at opposite ends of the earth’s orbit, Copernicus answers that there is such a movement, but the great distance of the stars (“firmament”) makes it imperceptible to us. (A moderate degree of such movement is now observable.)

  He sums up his system in a compact paragraph:

&n
bsp; First and above all lies the sphere of the fixed stars, containing itself and all things, for that very reason immovable.... Of the moving bodies [planets] first comes Saturn, who completes his circuit in thirty years. After him Jupiter, moving in a twelve-year revolution. Then Mars, who revolves biennially. Fourth in order, an annual cycle takes place, in which... is contained the earth, with the lunar orbit as an epicycle. In the fifth place Venus is carried round in nine months. Then Mercury holds the sixth place, circulating in the space of eighty days. In the middle of all dwells the sun... Not ineptly some call it the lamp of the universe, others its mind, and others again its ruler... rightly, inasmuch as the sun, sitting on a royal throne, governs the circumambient family of the stars.... We find, therefore, under this orderly arrangement, a wonderful symmetry in the universe, and a definite relation of harmony in the motion and magnitude of the orbs, of a kind it is not possible to obtain in any other way.* 47

  Generally an advance in human theory carries with it many remnants of the theory displaced. Copernicus based his conceptions on observations handed down by Ptolemy, and he retained much of the Ptolemaic celestial machinery of spheres, epicycles, and eccentrics; the rejection of these would wait for Kepler. Most eccentric of all was Copernicus’s calculation that the sun was not quite at the center of the earth’s orbit. The center of the universe, he reckoned, would be “three sun-diameters away from the sun”; and the centers of the planetary orbits were likewise outside the sun, and not at all identical. Copernicus transferred from the earth to the sun two ideas now rejected: that the sun is the approximate center of the universe, and that it is at rest. He thought of the earth as having not only an axial rotation and an orbital revolution, but a third motion, which he supposed necessary to explain the inclination of the earth’s axis and the precession of the equinoxes.

  Consequently we must not smile in hindsight at those who took so long to adopt the Copernican system. They were required not only to set the earth turning and hurtling in space at an alarming speed, contrary to the direct evidence of the senses, but to accept a mathematical maze only slightly less bewildering than Ptolemy’s. Not until Kepler, Galileo, and Newton should work out the mechanism of the new theory to greater simplicity and accuracy would it appear clearly superior to the old; and even then we should have to say of the sun what Galileo may have said of the earth—eppur si muove. Meanwhile Tycho Brahe rejected the heliocentric hypothesis on the ground that Copernicus had not convincingly answered Ptolemy’s objections. More surprising than such a rejection is the relative celerity with which the new system was accepted by astronomers like Rheticus, Osiander, John Field, Thomas Digges, and Erasmus Reinhold—whose “Prutenic Tables” (1551) of celestial motions was in large part based on Copernicus. The Catholic Church raised no objection to the new theory so long as it represented itself as an hypothesis; but the Inquisition struck back mercilessly when Giordano Bruno assumed the hypothesis to be a certainty, and made explicit its consequences for religion. In 1616 the Congregation of the Index forbade the reading of De Revolutionibus “until corrected”; in 1620 it allowed Catholics to read editions from which nine sentences had been removed that represented the theory to be a fact. The book disappeared from the revised Index of 1758, but the prohibition was not explicitly rescinded till 1828.

  The geocentric theory had fitted reasonably well a theology which supposed that all things had been created for the use of man. But now men felt tossed about on a minor planet whose history was reduced to a “mere local item in the news of the universe.” 48 What could “heaven” mean when “up” and “down” had lost all sense, when each would become the other in half a day? “No attack on Christianity,” wrote Jerome Wolf to-Tycho Brahe in 1575, “is more dangerous than the infinite size and depth of the heavens”—though Copernicus had not taught the infinity of the universe. When men stopped to ponder the implications of the new system they must have wondered at the assumption that the Creator of this immense and orderly cosmos had sent His Son to die on this middling planet. All the lovely poetry of Christianity seemed to “go up in smoke” (as Goethe was to put it) at the touch of the Polish clergyman. The heliocentric astronomy compelled men to re-conceive God in less provincial, less anthropomorphic terms; it gave theology the strongest challenge in the history of religion. Hence the Copernican revolution was far profounder than the Reformation; it made the differences between Catholic and Protestant dogmas seem trivial; it pointed beyond the Reformation to the Enlightenment, from Erasmus and Luther to Voltaire, and even beyond Voltaire to the pessimistic agnosticism of a nineteenth century that would add the Darwinian to the Copernican catastrophe. There was but one protection against such men, and that was that only a small minority in any generation would recognize the implications of their thought. The sun will “rise” and “set” when Copernicus has been forgotten.

  In 1581 Bishop Kromer raised a monument to Copernicus against the inner wall of Frauenburg Cathedral, next to the canon’s grave. In 1746 the monument was removed to make place for a statue of Bishop Szembek. Who was he? Who knows?

  III. MAGELLAN AND THE DISCOVERY OF THE EARTH

  The exploration of the earth progressed more rapidly than the charting of the skies, and with almost as disturbing influences on religion and philosophy. Geology advanced least, for the Biblical theory of creation was put beyond question by belief in its divine authorship. “If a wrong opinion should obtain regarding the creation as described in Genesis,” said the Italian-English reformer, Peter Martyr Vermigli, “all the promises of Christ fall into nothing, and all the life of our religion would be lost.”49 Aside from Leonardo’s scattered suggestions, the most significant work in geology in the first half of the sixteenth century was done by Georg Agricola. Note this passage from De ortu et causis subterraneorum (Basel, 1546) on the origin of mountains:

  Hills and mountains are produced by two forces, one of which is the power of water, the other the strength of the wind; we must add the fire in the interior of the earth.... For the torrents first of all wash out the soft earth, next carry away the harder earth, and then roll down the rocks, and thus in a few years they excavate the plains or slopes.... . By such excavation to a great depth through many ages there arises an immense eminence.... Streams... and rivers effect the same result by their rushing and washing; for this reason they are frequently seen flowing either between very high mountains, which they have created, or close by the shore which borders them.... . The wind produces hills and mountains in two ways: either... it violently moves and agitates the sand, or also when, after having been driven into the hidden recesses of the earth... it struggles to burst out.50

  Agricola’s De natura fossilium (1546) was the first systematic treatise on mineralogy; his De re metallica included the first systematic stratigraphy, and gave, as we have seen, the first explanation of ore deposits.

  Ethnography produced two major works: the Cosmographia universalis (1544) of Sebastian Münster, and the Descriptio Africae (1550) of “Leo Africanus.” Al-Hasan ibn-Muhammad al-Wazzan was a Moor from Granada; he traveled through Africa, and south to the Sudan, with the avidity of Ibn-Batuta; he was captured by Christian pirates and sent to Rome as a present to Leo X, who, impressed by his scholarly attainments, freed and pensioned him. He responded by accepting Christianity and Leo’s name. During the next thirty years he composed his book, first in Arabic, then in Italian. Before it came from the press he returned to Tunis; and there he died in 1552, apparently in the faith of his fathers.51

  It was an exciting age for geography. Reports poured in from missionaries, conquistadores, navigators, travelers, adding immensely to Europe’s knowledge of the globe. The Spanish who in this period conquered Mexico, California, Central America, and Peru were first of all adventurers, tired of poverty and routine at home, and facing with pleasure the perils of distant and alien lands. Amid the hardships of their reckless enterprise they forgot civilized restraints, frankly adopted the morality of superior guns, and accomplished an ac
t of continental robbery, treachery, and murder forgivable only because here and there—if an interested party may judge—the ultimate result was a gain for civilization. Yet there is little doubt that the conquered were at the time more civilized than their actual conquerors. Think of the Mayan culture found in Yucatán by Hernández de Córdova (1517), and the Aztec Empire of the Montezumas conquered by Hernando Cortes (1521), and the socialistic civilization of the Incas destroyed in Francisco Pizarro’s conquest of Peru (1526-32). We cannot know into what forms, noble or ignoble, these civilizations would have developed had they possessed the weapons to defend themselves.

  The geographical revelation proceeded. Sebastian Cabot, under a Spanish flag, explored Argentina, Uruguay, and Paraguay. De Soto crossed Florida and the Gulf States into Oklahoma. Pedro de Alvarado discovered the empire of Texas, and Francisco de Coronado moved through Arizona and Oklahoma to Kansas. The mines of Potosi in Bolivia began to send their silver to Spain (1545). Year by year the map of the New World was charted in gold, silver, and blood. The English and French lagged behind in the great raid, because those parts of North America which the Spanish and Portuguese left to them were poor in precious metals, and forbidding in forests. John Rut sailed along the coast of Newfoundland and Maine. Giovanni da Verrazano was sent by Francis I to find a northwest passage to Asia; he landed on North Carolina, entered New York harbor (which remembers him with a statue at the Battery), and rounded Cape Cod to Maine. Jacques Cartier, under the flag of France, sailed up the St. Lawrence to Montreal, and established a French claim to Canada.