The Scientific Revolution and the Church

The relationship between the Scientific Revolution and the Christian churches is one of the most carefully studied and most frequently misunderstood topics in the history of early modern Europe. The standard caricature — the Church persecuting science, science liberating the human mind from religious superstition — does not survive contact with the actual record. The reality is far more interesting, far more tangled, and far more important for understanding both the Scientific Revolution and the long history of relations between science and religion. The seventeenth century was, of course, a century in which the new science came into sharp conflict with elements of established religious teaching. The trial of Galileo in 1633, the condemnation of Copernican works by the Roman Inquisition in the same year, the slow exclusion of the new astronomy from Catholic universities, the resistance of many Protestant theologians to the heliocentric cosmology — these are real events, and they mattered. But they were also embedded in a much larger and more complex story, in which devout Christians of every confession played central roles in founding and supporting the new science, in which religious institutions were major patrons of natural philosophy, and in which the new science itself was often pursued as a form of devotion. The long-term consequence of the Scientific Revolution was not the displacement of religion by science, but the gradual separation of their proper domains. By the late eighteenth century, it was widely accepted that science and religion answer different questions, and that conflicts between them are usually the result of one or the other overstepping its proper boundaries. That modern settlement, so familiar that it now seems natural, was the hard-won product of two centuries of argument, negotiation, and occasional conflict. This section examines how it was reached. For a broader account of the impact of the revolution on European society, see The Impact of the Scientific Revolution on Society. For the personal story of the most famous confrontation between a natural philosopher and the Roman Inquisition, see Galileo Galilei and the article on the Trial of Galileo.

The Medieval Synthesis and Its Discontents

To understand why the relationship between the new science and the Church became so contentious, it is necessary to begin with the medieval synthesis that the Scientific Revolution broke. Throughout the Latin Middle Ages, there had been a generally accepted understanding of the relationship between natural philosophy and Christian theology. Aristotle’s natural works, mediated through Arabic and Latin commentators, provided the framework for understanding the physical world. The Bible and the writings of the Church Fathers provided the framework for understanding the spiritual world. The two frameworks were understood to be compatible, with theology taking precedence in cases of apparent conflict. This synthesis was not uncontested in the Middle Ages, but it was the dominant view. It had the support of the great thirteenth-century Dominican and Franciscan theologians, of the medieval universities, and of the papacy. The Aristotelian natural philosophy it embedded — with its geocentric cosmos, its four elements, its qualitative changes, its four terrestrial causes — was the only formal natural philosophy available to Latin Christendom. To attack it was, by implication, to attack the framework within which the Christian doctrine of creation was being taught. By the sixteenth century, however, the medieval synthesis was already fraying at the edges. The recovery of new Greek texts, including the works of Archimedes and the mathematical writings of the ancient mathematicians, had begun to provide alternative conceptual resources. The Protestant Reformation had shattered the religious unity of Western Christendom and weakened the authority of the papacy. The voyages of discovery had revealed a natural world much larger and more varied than the medieval synthesis had anticipated. And the printing press had made it possible to publish, distribute, and debate new ideas at a scale and speed that the medieval universities could not match. The background to this transformation is explored in An Overview of the Scientific Revolution.

The Copernican Challenge

The first great challenge to the medieval synthesis came from astronomy. Copernicus’s De revolutionibus orbium coelestium (1543) proposed a heliocentric model of the solar system, with the earth rotating on its axis and revolving around the sun. The work was, in its outer form, a technical astronomical treatise addressed to fellow astronomers, and Copernicus dedicated it to Pope Paul III in terms that acknowledged the religious dangers of the new cosmology. Within a generation, however, the work was being read as something more than a technical proposal for astronomical convenience. It was being read as a claim that the literal sense of certain biblical passages — Joshua’s command to the sun to stand still, for example, or the Psalmist’s description of the sun running its course — was incompatible with the true structure of the cosmos. The full complexity of the Church’s response is examined in How Did the Church Respond to Heliocentrism?, and the deeper reasons for the Church’s resistance are analyzed in Why Did the Church Oppose Heliocentrism?. The brief version is that the response was neither uniform nor immediate, and that it took the better part of a century for the Catholic Church to develop a settled policy.

The Galileo Affair

The most famous episode in the long confrontation between the reformed natural philosophy and the Catholic Church is the trial of Galileo Galilei in 1633. The story begins in 1610, when Galileo, using the newly invented telescope, observed four moons orbiting Jupiter, the phases of Venus, and the irregular surface of the moon — observations that supported the Copernican system and damaged the Ptolemaic. In 1613 he wrote a letter to the Grand Duchess Christina in which he argued, on theological grounds, that the Bible was not intended to teach astronomy and that the natural philosopher, on the basis of demonstration, was entitled to interpret scripture. In 1616 the Roman Inquisition examined the Copernican doctrine and declared it “formally heretical” in the sense in which the doctrine contradicted the literal sense of scripture. Galileo was privately admonished not to hold or defend the Copernican opinion. In 1623 Maffeo Barberini, a friend of Galileo, was elected pope as Urban VIII. The new pope, a cultured man and an admirer of Galileo, gave the latter permission to write a comparative discussion of the Ptolemaic and Copernican systems, provided the treatment was neutral. The result was the Dialogue Concerning the Two Chief World Systems (1632), which, despite its official neutrality, presented the Copernican system so persuasively that it was widely read as a defense of heliocentrism. The book was referred to the Inquisition, and Galileo was tried, found “vehemently suspect of heresy,” forced to recant, and sentenced to house arrest, where he remained until his death in 1642. The case has been the subject of intensive historical study. The most common caricature — that the Church suppressed science and that Galileo was a martyr to reason — does not survive contact with the evidence. Galileo was a friend of the Church, a friend of the pope, and a man whose religious sincerity is not in doubt. The Church’s treatment of him was unjust, but it was the product of a complex set of theological, political, and personal factors, not of a simple opposition to science. The story is told in the article on the Trial of Galileo and in the deeper analysis of the Church’s response to heliocentrism.

The Role of the Religious Orders

A frequently overlooked feature of the relationship between the experimental science and the Church is the active role played by the religious orders — most prominently the Jesuits — in the practice and teaching of the new natural philosophy. The Jesuits, founded by Ignatius of Loyola in 1540, became in the late sixteenth and seventeenth centuries the leading teaching order of the Catholic Church, with a network of colleges and universities across Europe. Their educational program, codified in the Ratio studiorum of 1599, included a substantial place for natural philosophy, taught in substantial part from Aristotle but increasingly supplemented with new mathematical, observational, and experimental material. Jesuit scholars made important contributions to the new philosophy of nature. Christoph Scheiner, a Jesuit astronomer, made systematic observations of sunspots in the 1610s and 1620s, in the course of which he became embroiled in a priority dispute with Galileo. Athanasius Kircher, another Jesuit, compiled vast encyclopedic works on magnetism, optics, music, geology, and Egyptology, and his correspondence network was one of the principal channels of scientific communication in seventeenth-century Europe. The Jesuits also operated important observatories and were responsible for the introduction of the telescope and the microscope into many Catholic institutions. The Jesuits were not, of course, Copernicans. The order’s teaching on cosmology remained largely Ptolemaic until well into the eighteenth century, and Jesuit theologians were among the more vigorous opponents of the heliocentric doctrine. But the order’s engagement with the new natural philosophy was genuine, and it is a useful corrective to the simple picture of the Catholic Church as uniformly hostile to the new learning. Protestant religious institutions were also deeply involved in the seventeenth-century science. The Lutheran and Reformed universities in the German lands, the Dutch universities (especially Leiden), the Anglican colleges at Oxford and Cambridge, and the Puritan communities of the English Revolution all contributed to the establishment of the new natural philosophy. John Ray, the great English naturalist of the late seventeenth century, was a devout Anglican whose natural history was explicitly framed as a contribution to natural theology. The young Newton’s religious heterodoxy — his anti-Trinitarianism eventually made it inadvisable for him to take holy orders — did not prevent him from being appointed to the Lucasian Chair of Mathematics at Cambridge, the most prestigious scientific position in England.

The Index of Prohibited Books

The institutional instrument by which the Catholic Church managed its relationship with the new natural knowledge was the Index Librorum Prohibitorum — the Index of Prohibited Books, first published in 1559 under Pope Paul IV and revised frequently until its final abolition in 1966. The Index listed books that Catholics were forbidden to read, possess, or print without permission. It included theological heresies, Protestant works, and a substantial list of scientific and philosophical works. Copernicus’s De revolutionibus placedd on the Index in 1616, “until corrected.” The corrected version, published in 1620, removed or modified certain passages that had been read as asserting the literal truth of heliocentrism, and declared the Copernican hypothesis to be a mathematical device for the saving of appearances rather than a claim about the real structure of the cosmos. Galileo’s Dialogue placedd on the Index in 1634, where it remained until 1835. Kepler’s Epitome of Copernican Astronomy placedd on the Index in 1619. The full list of scientific works on the Index was not large. Most of the major scientific works of the seventeenth century — Newton’s Principia, for example — never appeared on the Index, either because they were not considered theologically problematic or because the authorities never noticed them. The Index was a clumsy instrument, and its enforcement was uneven. In many Catholic countries, copies of prohibited works circulated freely, especially among the educated. But the Index did establish, in symbolic terms, the principle that the Church retained the authority to determine which claims about the natural world were compatible with Catholic doctrine. The slow liberalization of the Index is one of the more striking institutional histories of the eighteenth century. In 1662 the Sacred Congregation of the Index modified the decree of 1616 to permit the reading of Copernicus’s De revolutionibus by experts, on condition that it was read as a mathematical hypothesis. In 1757, under Pope Benedict XIV, the prohibition on all books teaching the heliocentric doctrine as true was removed. The change reflected a broader shift in Catholic thinking, partly driven by the evident success of Newtonian science, partly by the Enlightenment demand for intellectual freedom, and partly by the realization that the prohibition was no longer enforceable. The story is told in How Did the Church Respond to Heliocentrism?.

The Protestant Response

The Protestant churches, lacking a central authority comparable to the papacy, responded to this new approach in a more fragmented way. Martin Luther, on first hearing of Copernicus in 1539, dismissed him as a fool who wished to reverse the entire science of astronomy; sacred scripture, in Luther’s reading, plainly stated that Joshua had commanded the sun, not the earth, to stand still. John Calvin, more cautious, declined to commit himself on the astronomical question, but insisted that the earth could not be moved without doing violence to the Psalmist’s words. These initial reactions did not, however, set the tone for the longer-term Protestant response. By the late seventeenth century, many of the most important centers of the reformed natural philosophy were in Protestant countries — the Netherlands, England, the Protestant German states, Scandinavia. The Lutheran and Reformed churches developed their own accommodations with the new natural philosophy, generally less rigid than the Catholic accommodation and sometimes more intellectually adventurous. The most striking feature of the Protestant response was the rise of physico-theology or natural theology — the project of inferring the existence and attributes of God from the study of nature. The natural-theology program, which reached its most elaborate form in William Derham’s Astro-Theology (1714) and William Paley’s Natural Theology (1802), was not a Protestant monopoly, but it was particularly congenial to the Protestant tradition, with its emphasis on the individual’s direct reading of the “book of nature” alongside the “book of scripture.” The metaphor of the two books, both written by God, was a powerful tool for accommodating the experimental science within a Christian framework.

The Deism Question

By the early eighteenth century, the new philosophy of nature had become one of the principal supports of a more radical religious position, deism — the view that the natural world is sufficient evidence of God’s existence and attributes, and that organized religion, revelation, and the Church are at best superfluous additions. The deist writers of the early Enlightenment — John Toland, Matthew Tindal, Thomas Chubb in England, Voltaire in France — used the new learning to argue that the evidence of design in nature was enough to establish a creator, and that priestly mediation between God and the human race was unnecessary. The deist position was a logical extension of the natural-theology program, but it alarmed orthodox Christians of every confession. The controversy it generated — sometimes called the deist controversy — was one of the principal intellectual preoccupations of the early Enlightenment, and it shaped the religious landscape of the eighteenth century. The orthodox Christian response was to insist that natural theology, however valuable, was not sufficient; that revelation and grace were needed in addition to reason; and that the seventeenth-century science, properly understood, was a support for Christianity rather than a substitute for it. The deist controversy is one of the bridges between the Scientific Revolution and the Enlightenment.

The Long Accommodation

The slow separation of the domains of science and religion that we now take for granted was the product of the seventeenth and eighteenth centuries. The settlement was not the work of any single thinker or any single council. It emerged gradually, through a long process of negotiation, argument, and occasional conflict, as both science and religion adjusted to the demands of the new situation. By the late nineteenth century, the settlement was in its modern form: science and religion answer different kinds of questions, and conflicts between them are the result of one or the other trespassing on the other’s territory. The settlement was not universally welcomed. Many religious thinkers in the nineteenth and twentieth centuries rejected it as a surrender of religious authority, and many scientists rejected it as an illegitimate concession to religious thinking. The relationship between science and religion remains contested. But the modern separation of domains, however imperfect its enforcement, was one of the durable achievements of the Scientific Revolution, and it is difficult to imagine how it could have been reached without the long, complex, and often bitter negotiations of the seventeenth and eighteenth centuries.

Related Articles

• The Impact of the Scientific Revolution on Society
• How Did the Church Respond to Heliocentrism?
• Why Did the Church Oppose Heliocentrism?
• Did the Catholic Church Oppose All Science?
• Galileo Galilei
• The Trial of Galileo
• The Protestant Reformation and the Scientific Revolution
• An Overview of the Scientific Revolution