Why Did the Church Oppose Heliocentrism?
The deeper reasons for the Church's resistance — biblical literalism, Aristotelian physics, the role of the Church as arbiter of truth, and the slow process of scriptural reinterpretation.
Why Did the Church Oppose Heliocentrism?
The Catholic Church’s opposition to heliocentrism, which led to the condemnation of Galileo in 1633 and to the prohibition of Copernican works for more than a century, is one of the most discussed events in this history. The simple explanation — that the Church opposed heliocentrism because it contradicted the Bible — is part of the story, but it is far from the whole story. The deeper reasons are multiple, and they interact in ways that are still being worked out by historians. To understand them, it helps to recall that the heliocentric doctrine, first proposed by Copernicus and confirmed by Galileo’s telescopic observations, challenged not only biblical interpretation but the entire Aristotelian cosmology in which Catholic theology had been embedded for centuries. This article looks at the four most important: the doctrine of biblical literalism, the embedding of Aristotelian physics in Catholic theology, the role of the Church as the authoritative arbiter of truth, and the slowness of the interpretive process by which a new cosmology could be reconciled with sacred scripture. The full account of the institutional response is given in How Did the Church Respond to Heliocentrism?, and the broader context is set in The Scientific Revolution and the Church. For the personal story of the confrontation, see The Trial of Galileo. And for the heliocentric system itself, see Heliocentrism and Astronomy.
Biblical Literalism and the Sun of Joshua
The most immediate religious objection to heliocentrism was the apparent contradiction between the new astronomy and the literal sense of several biblical passages. The most famous of these is the account in the book of Joshua, chapter 10, in which Joshua, during the battle against the Amorites, commands the sun to stand still — “Sun, stand thou still upon Gibeon” — and the sun obeys. On a heliocentric system, the appropriate command would have been addressed to the earth, and the appropriate miracle would have been the arrest of the earth’s rotation. On a geocentric system, the literal sense of the text is perfectly natural. The Psalmist’s language was even more difficult. Psalm 19 begins “The heavens declare the glory of God; and the firmament sheweth his handywork. Day unto day uttereth speech, and night unto night sheweth knowledge.” It continues, in the version familiar to early modern Christians, with the description of the sun running its course: “In them hath he set a tabernacle for the sun, which is as a bridegroom coming out of his chamber, and rejoiceth as a strong man to run a race. His going forth is from the end of the heaven, and his circuit unto the ends of it.” On any heliocentric system, the language of the sun running a race is not strictly literal. On a geocentric system, it is. There were, of course, ways of reading these passages as non-literal even before Copernicus. St. Augustine, in The Literal Interpretation of Genesis, had argued that the Bible, in matters of natural philosophy, accommodates itself to the limited understanding of its readers, and that it is therefore improper to read its cosmological passages as scientific claims. The medieval theologians had generally agreed. But the dominant late-medieval and early-modern Catholic practice, shaped by the literal-historical reading of scripture that the Reformation had made newly urgent, was to take the biblical text as the standard against which any new claim about the natural world had to be judged. The Catholic response to the heliocentric challenge was, in part, an application of this principle. The Holy Office’s formal judgment in 1616, that the proposition that the sun is at the center of the world is “formally heretical” because it contradicts the literal sense of scripture, was an expression of the view that the literal sense of the relevant passages was clear and that the new astronomy could not be reconciled with it.
Aristotelian Physics in Catholic Theology
The second reason for the Church’s opposition to heliocentrism is less well known but no less important: Aristotelian physics had been embedded in Catholic theology over centuries of medieval and early-modern commentary, and the heliocentric system was incompatible with that physics in ways that went beyond the astronomical. Aristotle’s natural philosophy, mediated through the commentaries of Aquinas and the late-scholastic Jesuit manuals, was the natural philosophy in which Catholic theology had been formulated. The Aristotelian cosmos was geocentric, with the earth at the center of the world and the heavens rotating around it. The Aristotelian physics of motion distinguished sharply between the natural motion of heavy bodies (toward the center of the earth) and the natural motion of light bodies (away from the center), and explained projectile motion by the action of a surrounding medium. Aristotle’s argument against the existence of a vacuum, the horror vacui, was a basic element of the physics taught in Catholic universities. The Aristotelian theory of place, with its distinction between the natural place of an element and the place to which it is forced, was a standard part of the natural-philosophical curriculum. The heliocentric system, and the new physics that went with it, was incompatible with all of this. The earth’s rotation was incompatible with the Aristotelian physics of motion. The earth’s revolution around the sun was incompatible with the Aristotelian account of the order of the cosmos. The vacuum of interplanetary space was incompatible with the horror vacui. The whole Aristotelian system, as taught in the Catholic universities, was entangled with the geocentric cosmology, and a challenge to geocentrism was implicitly a challenge to the whole system. The Church’s opposition to heliocentrism was therefore not just a matter of defending particular biblical passages. It was also a matter of defending an entire intellectual framework in which Catholic theology had been formulated. The Jesuits, who taught the Aristotelian physics in their colleges, were the principal upholders of this framework, and their resistance to the new science was not primarily theological but pedagogical. The Aristotelian system, however inadequate, was the system they knew how to teach, and the system on which the Catholic educational program was based.
The Church as Arbiter of Truth
The third reason for the Church’s opposition to heliocentrism is institutional rather than theological. The Catholic Church of the sixteenth and seventeenth centuries was not just a religious body; it was also a major intellectual, social, and political institution with a long history of claiming authority over the truth. The claim was not unique to the Church — it was also made by the Protestant churches, by the universities, and by the various secular authorities. But the Catholic Church, with its centralized hierarchy, its formal mechanisms of doctrinal definition, and its institutionalized authority in the form of the Holy Office and the Index, was the institution with the most developed apparatus for the determination of orthodox belief. The heliocentric claim was a direct challenge to that authority. If a natural philosopher could, on the basis of mathematical argument and telescopic observation, establish a claim about the natural world that contradicted the traditional reading of scripture, then the question of which authority was competent to determine the truth about such matters was reopened. The Church’s response — the formal condemnation of the Copernican doctrine in 1616, the trial and condemnation of Galileo in 1633, the prohibition of heliocentric works by the Index — was, in part, an attempt to maintain the principle that the Church retained the authority to determine the truth in matters touching both scripture and natural philosophy. The Galileo affair, in other words, was not just a matter of astronomy and scripture. It was a matter of the social and institutional position of the Church in early modern Europe. The Church could not afford to appear to surrender a domain of authority to a competing source, especially not in the context of the Protestant Reformation, in which the authority of the Church was already under attack. The resistance to heliocentrism was, in part, a resistance to the secularization of knowledge.
The Slowness of the Interpretive Process
The fourth reason for the Church’s opposition to heliocentrism is the most subtle, and the one most often overlooked. The interpretive process by which a new scientific claim can be reconciled with sacred scripture is, by its nature, slow. It requires the accumulation of evidence, the growth of alternative readings of the relevant biblical passages, the resolution of conflicts with established natural philosophy, and the gradual cultural acceptance of the new claim. The Church’s resistance to heliocentrism, in other words, was not just a matter of an authoritarian institution imposing an arbitrary doctrine. It was also a matter of an institution waiting, in good faith, for the new claim to be established with sufficient certainty to justify a revision of the traditional reading of scripture. The principle was stated clearly by Cardinal Bellarmine in 1615: if a demonstrative proof of the earth’s motion were produced, the Bible would have to be reinterpreted. The principle was reasonable. The application of the principle — the demand for a demonstrative proof before accepting the new claim — was also reasonable, given the institutional position of the Church and the strength of the traditional reading. What was unreasonable, in retrospect, was the implicit assumption that the new claim could be settled by the application of the traditional criteria of demonstration, without taking account of the new criteria of observational and experimental adequacy that the new science was developeding. The slow acceptance of heliocentrism was, in part, a function of the slow development of the new criteria. Until Newton’s Principia of 1687 provided a comprehensive mechanical account of the solar system, the heliocentric hypothesis was observationally well supported but physically unexplained. The absence of a satisfactory physics was a serious obstacle to acceptance, and the Church’s slowness in withdrawing its opposition was, in part, a response to the slowness of the physics.
The Decoupling of Scripture and Cosmology
The eventual resolution of the heliocentrism controversy was a process of decoupling. The new science was gradually allowed to determine the structure of the cosmos on its own terms, with the Bible understood to be concerned with the salvation of the soul rather than with the description of the heavens. The decoupling was not a single decision; it was a slow, contested process, in which the theologians, the natural philosophers, the institutional authorities, and the wider culture all played a part. The decoupling was made possible by a number of intellectual moves. One was the growth of the doctrine of accommodation, in which the Bible is understood to accommodate its language to the limited understanding of its original readers, and to be therefore not strictly literal in matters of natural philosophy. Another was the doctrine of double truth, in which the same proposition can be true in natural philosophy and false in theology, or vice versa, on the ground that the two disciplines have different standards of evidence. A third was the growth of natural theology, in which the existence and attributes of God are inferred from the study of nature rather than from the reading of scripture, and the Bible is therefore understood to be a book of revelation rather than a book of cosmology. Each of these moves was controversial, and the conflicts they generated shaped the intellectual landscape of the seventeenth and eighteenth centuries. The decoupling, when it was eventually achieved, was one of the most important cultural achievements of the Scientific Revolution, and it is the immediate ancestor of the modern view that science and religion answer different kinds of questions.
The Historiographical Debate
The standard account of the Galileo affair, in which the Church is cast as the villain and Galileo as the martyr of science, is now widely regarded as inadequate. The more nuanced account, which has emerged from several generations of careful historical work, recognizes that the Church’s opposition to heliocentrism was driven by a complex set of factors, that the new science was not simply on the side of truth and the Church on the side of error, and that the eventual decoupling of science and religion was a long, hard-won cultural achievement rather than a sudden revelation. The historiographical debate is still active. Some scholars emphasize the role of institutional self-interest in the Church’s opposition; others emphasize the role of sincere theological conviction. Some emphasize the role of Aristotelian natural philosophy; others emphasize the role of the biblical interpretation. Some emphasize the slowness of the new science in establishing its claims; others emphasize the slowness of the Church in adjusting its position. The most balanced accounts take all of these factors into account, and treat the eventual decoupling as the product of a long negotiation between the new science and the older religious tradition. The Galileo affair is, in any case, not just a historical curiosity. It is a central case in the broader history of the relationship between science and religion, and it continues to be cited, by both sides, in contemporary debates about the proper relationship between the two.