The Case for God (32 page)

Intrigued by Copernicus’s hypothesis, some scientists tried to develop his ideas. In his observatory on the island of Hveen in the Swedish Sound, the Danish astronomer, mathematician, and imperial astrologer Tycho Brahe (1546–1601) corrected outstanding inaccuracies in the astronomical table and discovered a new star in Cassiopeia. He rejected Copernicus’s theory, however, and suggested a compromise with the Ptolemaic system: the planets rotated round the sun, which revolved around the stationary Earth. The English astronomer William Gilbert (1540–1603) thought that the Earth might have an inner magnetism that caused it to turn daily on its axis. In Italy, the Dominican friar Giordano Bruno (1548–1600) left his religious order in 1576 and inveighed against the inadequacies of Aristotelian physics. Fascinated by the ancient hermetic religion of Egypt, Bruno was convinced that esoteric spiritual exercises could
give the philosopher direct access to the divine life that lay hidden behind the veil of physical reality.
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This, he claimed, was the real meaning of heliocentric theory, which Copernicus—a mere jobbing mathematician—had not fully understood.

Arguably the most brilliant of these pioneering scientists was the German astronomer Johannes Kepler (1571–1630),
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who had corresponded with Brahe, helped him in his work, and succeeded him in the post of imperial astrologer. Like Copernicus, Kepler was convinced that mathematics was the key to understanding the cosmos and that the scientist’s task was to test his mathematical theories against rigorous empirical observation. In 1609, he published
Mysterium cosmographicum
, the first public attempt to justify and refine Copernicus’s heliocentric theory, which had been unnecessarily complicated by Copernicus’s retention of the circular planetary orbits; there were also outstanding problems with his hypothesis. What kept terrestrial objects from flying off the earth as it traveled through space at such high speed? After struggling for ten years to find a way of confirming the idea that the planets moved in perfect circles, Kepler was finally persuaded by Brahe’s remarkably accurate observations to jettison it and, basing his calculations on Euclidean geometry, formulated the first “natural laws”—precise, verifiable statements about particular phenomena that were universally applicable.
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First: the planets moved in elliptical rather than circular orbits, traveling at speeds that varied proportionately according to their distance from the sun. Second: while in orbit, the planet would sweep out equal areas of the ellipse in equal intervals of time. Third: the ratio of the squares of the orbital periods was exactly equal to the ratio of the cubes of their average distance from the sun.
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Kepler also suggested that instead of being moved by the automatic motion of the spheres, the planets were moved by mathematical forces. Extending Gilbert’s theory of the earth’s magnetism to all celestial bodies, he suggested that the elliptical orbits of the planets were created by the moving force
(anima motrix
) of the sun, combined with its own magnetism and that of the planets. The universe was, therefore, a self-regulating machine and ran on the same principles that governed dynamics here on earth.
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In reaching these groundbreaking conclusions, Kepler had depended not only on mathematics and empirical observation but on
the same kind of hermetic mystical speculations as Bruno. He too was convinced that Copernicus had not understood the full implications of his theory, which he had stumbled upon “like a blind man, leaning on a stick as he walks.”
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But with the aid of theology, he, Kepler, would show that it was no accident that the universe took the form it did.
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Geometry was God’s language; like the Word that had existed with God from before the creation, it was identical with God.
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So the study of geometry was the study of God, and by studying the mathematical laws that inform all natural phenomena, we commune with the divine mind.
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Because he was convinced that God had impressed his image on the cosmos, Kepler saw the Trinity everywhere. The Trinity was the “form and archetype” of the only three stationary things in the universe: the sun, the fixed stars, and the space between the heavenly bodies.
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The planets rotated in their orbits because of a mystic force, emanating from the sun in the same way as the Father creates through the Son and sets things in motion through the Spirit.
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The solar system did not merely remind Kepler of the Trinity; he insisted that the Trinity had in part prompted his discoveries. But he was not entirely swept away by religious enthusiasm. He knew that the theological truth he found in the cosmos was dependent upon mathematics, empirical observation, and measurement. “If they do not agree, the whole of the preceding work has undoubtedly been a delusion.”
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Today it is often assumed that modern science has always clashed with religion. Kepler, a mathematician of extraordinary genius, reminds us that early modern science was rooted in faith. These pioneering scientists had no desire to get rid of religion. Instead, they would develop a secular theology, written by and for laymen, because their discoveries made them think differently about God. During the sixteenth and seventeenth centuries, science, philosophy, and religion were tightly welded together. Kepler was convinced that during his mathematical exploration of the universe, he had “followed with sweat and panting the footprints of the Creator.”
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Scientists had to cast aside everything they thought they knew and confront the unknown—in rather the same way as their contemporary John of the Cross encountered the unknown God, telling his readers: “To come to the knowledge you have not, you must go by a way in which you know not.”
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If they did not have the courage to move beyond the
safety of received ideas, mystic and scientist alike would become trapped in theories that were no longer adequate.

At the end of the sixteenth century, however, the intolerant strain of modernity came to the fore in Italy, the home of the Renaissance. The Protestant Reformation had been traumatic for all Catholics, but Italians had also witnessed the sack of Rome by German mercenary troops in 1527, the collapse of the republic of Florence in 1536, and, finally, the Spanish domination of the Italian peninsula. Put on the defensive, the Catholic hierarchy became fanatically intent on achieving absolute control over their subjects—many of whom were willing in these fearful times to trade the burden of freedom for the consolations of certainty. The theology of Thomas Aquinas and the philosophy and science of Aristotle, transformed beyond all recognition into a rigid system of dogma, became Catholic orthodoxy; all other schools of thought were regarded with deep suspicion. In 1559, Pope Paul IV had issued the first official Index of Prohibited Books and Pope Pius V (1566–72) set up the Congregation of the Index to supervise the Vatican program of censorship. As a result, at the turn of the seventeenth century, there was a spate of condemnations. It was now extremely dangerous to criticize Aristolelian cosmology. The work of the Italian philosopher Bernardino Telesio (1509–88) and the Dominican Tommaso Campanella (1568–1639) was condemned because of their opposition to Aristotle, and Campanella was imprisoned for twenty-seven years. Francesco Patrizi (1529–97) was forced to abjure the now “subversive” philosophy of Platonism and was condemned for teaching the infinity of interstellar space; Francesco Pucci (1543–97) was executed for his heterodox views on Original Sin; and in 1600, Giordano Bruno was burned at the stake for preaching the occult heresy that the stars had souls and that there existed an infinite number of worlds.
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It was in this grim political climate that the Italian astronomer Galileo Galilei (1564–1642) announced that he had proved Copernicus right. Unlike Kepler and Bruno, Galileo had no interest in the occult; instead of seeing the universe as a numinous reflection of the divine mystery, he described it as a cosmic mechanism ruled by mathematical laws. By observing the oscillation of a swinging lamp in the cathedral of Pisa, he had inferred the value of a pendulum for the
exact measurement of time. He had invented a hydrostatic balance, written a treatise on specific gravity, and proved mathematically that all falling bodies, whatever their size, descended to earth at the same velocity. One of his most famous achievements was to perfect the refracting telescope, through which in 1609 he observed the craters of the moon, sunspots, the phases of Venus, and the four moons of Jupiter. The spots on the sun and the pitted surface of the moon proved that these were not the perfect bodies described by Aristotle. It was now clear that Jupiter was a moving planet and was circled by satellites similar to our own moon. All this, Galileo concluded, was proof positive of the Copernican hypothesis. In 1610, he published
The Sidereal Messenger
to immediate acclaim. All over Europe, people made their own telescopes and scanned the heavens themselves. When Galileo visited Rome the following year, the Jesuits publicly confirmed his discoveries and, to enormous applause, Prince Federico Cesi made him a member of the Accademia dei Lincei.

The case of Galileo has become a cause célèbre, emblematic of what is thought to be the eternal and inherent conflict between science and religion. But, in fact, Galileo was a victim not of religion per se but of the post-Tridentine Catholic Church at a time when it felt an endangered species. Pope Urban VIII (1568–1644) made an appalling error when he silenced Galileo, but Galileo also made mistakes. Each represented the intolerance of modernity, which was beginning to overtake the more open, liberal, and healthily skeptical spirit of the Renaissance.

Galileo exemplified the precision and practical orientation of the emerging modern spirit. He insisted that it was impossible to understand a single word of the Book of Nature without knowing the language of mathematics. First the scientist should isolate the phenomenon he was observing—the swinging pendulum or the falling body. Next he must translate the problem into mathematical theorems, axioms, and propositions. Finally, his mathematical conclusions must be tested to ensure that they were an accurate fit with the physical phenomenon that had sparked the investigation. Instead of losing himself in mystical theories, the scientist should concentrate on an object’s measurable, quantitative characteristics—its size, shape, number, weight, or motion. Other qualities—taste, color, texture, or smell, which was what a nonspecialist would notice first—were irrelevant,
because they were merely subjective impressions.
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Scientists were beginning to develop an entirely different way of contemplating the world. When he looked at an object, Galileo bypassed its sensual properties—whether it was “white or red, bitter or sweet, sounding or mute, of a pleasant or non-pleasant odour”—and explored instead the abstract, mathematical principles that accounted for it.
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A scientist could believe in something that did not exist in his actual experience and could never be realized in the physical world, because his mathematical calculations had given him absolute confidence in its existence. Galileo was no longer content to speak hypothetically. Hypotheses were mere conjectures, matters of opinion, and it was the task of science to provide unequivocal certainty. Convinced that the sun-centered universe was a physical fact that could be established empirically, he committed himself to finding an incontrovertible proof that was “necessary,” that is, self-evident, irrefutable, and backed up by carefully observed physical evidence.
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If a scientist’s conclusions left any room for doubt, they were not, in his view, scientific.
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But of course it was not possible to prove religious truth in this way. To his dying day, Galileo adhered to the traditional relationship of
mythos
and
logos
and insisted that his theories did not in any way contradict religion. Mechanics (the study of motion) had nothing to say about theology. They were two entirely distinct disciplines, each with its own sphere of competence. Other early modern scientists would find it necessary to invoke God as an explanation for their theories, but not Galileo. In his famous “Letter to the Grand-Duchess Christina,” which set forth his views on the relationship of science and religion, he wholeheartedly endorsed Augustine’s principle of accommodation. Science focused on the material world, theology on God. The two disciplines should be kept separate and must not encroach upon each other’s domain. God was the author of both the Book of Nature and the Bible, and “two truths cannot contradict one another.”
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If scientists made statements about religion and if the devout claimed that scripture gave infallible information about the hidden structures of nature, there could only be the worst kind of confusion.
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Copernicus had understood this perfectly: he had always limited his remarks to “physical conclusions based above all on sensory experience and very accurate observations.”
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But in cases where there was no conclusive proof, Galileo argued that we should bow to
the authority of the Bible: “I have no doubt at all that, where human reason cannot reach, and where consequently one cannot have a science, but only opinion and faith, it is appropriate piously to conform absolutely to the literal meaning of scripture.”
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What Galileo did not seem to have realized was that the political climate had changed. The Vatican no longer regarded theology as a speculative science but was systematically reducing the teachings of Aristotle and Aquinas to an inflexible set of propositions formulated in such a way as to end all discussion and maximize certainty.
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In 1605, the Jesuit cardinal Robert Bellarmine (1542–1621), who epitomized this new attitude, had become papal theologian. For Bellarmine, the task of theology was simply to organize doctrines into neat systems that could be marshaled effectively against the enemies of the Church. The execution of Bruno had made it horribly clear that papal officials were ready to enforce the new orthodoxy using the same coercive methods as any early modern monarchy.