Before the Scientific Revolution, educated Europeans held a view of the world that derived from Aristotle, perhaps the greatest of the ancient Greek philosophers, and from Ptolemy, a Greco-Egyptian mathematician and astronomer who lived in Alexandria during the second century C.E. To medieval European thinkers, the earth was stationary and at the center of the universe, and around it revolved the sun, moon, and stars embedded in ten spheres of transparent crystal. This understanding coincided well with the religious outlook of the Catholic Church because the attention of the entire universe was centered on the earth and its human inhabitants, among whom God’s plan for salvation unfolded. It was a universe of divine purpose, with angels guiding the hierarchically arranged heavenly bodies along their way while God watched over the whole from his realm beyond the spheres. The Scientific Revolution was revolutionary because it fundamentally challenged this understanding of the universe.

The initial breakthrough in the Scientific Revolution came from the Polish mathematician and astronomer Nicolaus Copernicus, whose famous book On the Revolutions of the Heavenly Spheres was published in the year of his death, 1543. Its essential argument was that “at the middle of all things lies the sun” and that the earth, like the other planets, revolved around it. Thus the earth was no longer unique or at the obvious center of God’s attention.

Other European scientists built on Copernicus’s central insight, and some even argued that other inhabited worlds and other kinds of humans existed. Less speculatively, in the early seventeenth century Johannes Kepler, a German mathematician, showed that the planets followed elliptical orbits, undermining the ancient belief that they moved in perfect circles. The Italian Galileo (gal-uh-LAY-oh) developed an improved telescope, with which he made many observations that undermined established understandings of the cosmos. (See Zooming In: Galileo and the Telescope.) Some thinkers began to discuss the notion of an unlimited universe in which humankind occupied a mere speck of dust in an unimaginable vastness. The French mathematician and philosopher Blaise Pascal (1623–1662) perhaps spoke for many when he wrote, “The eternal silence of infinite space frightens me.”17

The culmination of the Scientific Revolution came in the work of Sir Isaac Newton (1642–1727), the Englishman who formulated the modern laws of motion and mechanics, which remained unchallenged until the twentieth century. At the core of Newton’s thinking was the concept of universal gravitation. “All bodies whatsoever,” Newton declared, “are endowed with a principle of mutual gravitation.”18 Here was the grand unifying idea of early modern science. The radical implication of this view was that the heavens and the earth, long regarded as separate and distinct spheres, were not so different after all, for the motion of a cannonball or the falling of an apple obeyed the same natural laws that governed the orbiting planets.

By the time Newton died, a revolutionary new understanding of the physical universe had emerged among educated Europeans: the universe was no longer propelled by supernatural forces but functioned on its own according to scientific principles that could be described mathematically. Articulating this view, Kepler wrote, “The machine of the universe is not similar to a divine animated being but similar to a clock.”20 Furthermore, it was a machine that regulated itself, requiring neither God nor angels to account for its normal operation. Knowledge of that universe could be obtained through human reason alone—by observation, deduction, and experimentation—without the aid of ancient authorities or divine revelation. The French philosopher René Descartes (day-KAHRT) resolved “to seek no other knowledge than that which I might find within myself, or perhaps in the book of nature.”24

Like the physical universe, the human body also lost some of its mystery. The careful dissections of cadavers and animals enabled doctors and scientists to describe the human body with much greater accuracy and to understand the circulation of the blood throughout the body. The heart was no longer the mysterious center of the body’s heat and the seat of its passions; instead it was just another machine, a complex muscle that functioned as a pump.

The movers and shakers of this enormous cultural transformation were almost entirely male. European women, after all, had been largely excluded from the universities where much of the new science was discussed. A few aristocratic women, however, had the leisure and connections to participate informally in the scientific networks of their male relatives. Through her marriage to the Duke of Newcastle, Margaret Cavendish (1623–1673) joined in conversations with a circle of “natural philosophers,” wrote six scientific texts, and was the only seventeenth-century English woman to attend a session of the Royal Society of London, created to foster scientific learning. In Germany, a number of women took part in astronomical work as assistants to their husbands or brothers. Maria Winkelman, for example, discovered a previously unknown comet, though her husband took credit for it. After his death, she sought to continue his work in the Berlin Academy of Sciences but was refused on the grounds that “mouths would gape” if a woman held such a position.

Much of this scientific thinking developed in the face of strenuous opposition from the Catholic Church, for both its teachings and its authority were under attack. The Italian philosopher Giordano Bruno, proclaiming an infinite universe and many worlds, was burned at the stake in 1600, and Galileo was compelled by the Church to publicly renounce his belief that the earth moved around an orbit and rotated on its axis.

But scholars have sometimes exaggerated the conflict of science and religion, casting it in military terms as an almost unbroken war. None of the early scientists rejected Christianity. Copernicus in fact published his famous book with the support of several leading Catholic churchmen and dedicated it to the pope. After all, several earlier Catholic writers had proposed the idea of the earth in motion. He more likely feared the criticism of fellow scientists than that of the church hierarchy. Galileo himself proclaimed the compatibility of science and faith, and his lack of diplomacy in dealing with church leaders was at least in part responsible for his quarrel with the Church.25 Newton was a serious biblical scholar and saw no inherent contradiction between his ideas and belief in God. “This most beautiful system of the sun, planets, and comets,” he declared, “could only proceed from the counsel and dominion of an intelligent Being.”26 Thus the Church gradually accommodated as well as resisted the new ideas, largely by compartmentalizing them. Science might prevail in its limited sphere of describing the physical universe, but religion was still the arbiter of truth about those ultimate questions concerning human salvation, righteous behavior, and the larger purposes of life.