Galileo’s Trial on Trial: From teleological science to mathematical empirical science

02 January 2013 By Ng Kam Weng | TinyURL TM

Precis: Secular critics of Christianity typically appeal to the infamous trial of Galilee Galileo in Rome (1616) as indisputable evidence that Christianity is an intolerant and intellectually bankrupt system. The secular critics’ story is one of the inexorable retreat of Christianity into the backwaters of social progress, and of its being left behind in the advancement of the knowledge enterprise. Consequently, one would have expected the Christian religion to wither at the margins of society and eventually go the way of the gypsies. But this has not been the case. It calls to mind Mark Twain’s remark, “The report on my death was an exaggeration.”


Secular critics of Christianity typically appeal to the infamous trial of Galilee Galileo in Rome (1616) as indisputable evidence that Christianity is an intolerant and intellectually bankrupt system. Bertrand Russell described the trial in these words,

Galileo, as everyone knows, was condemned by the Inquisition…he recanted, and promised never again to maintain that the earth rotates or evolved. The Inquisition was successful at putting an end to science in Italy, which did not revive there for centuries, but it failed to prevent men of science from adopting the heliocentric theory, and did considerable damage to the Church by its stupidity. Fortunately there were Protestant countries, where the clergy, how-ever anxious to do harm to science, were unable to gain control of the State.[1]

Voltaire in his essay on “Descartes and Newton” (1728) spiced up the episode even more to ensure dramatic effects: “the great Galileo, at the age of eighty, languished in the prison of the Inquisition for having demonstrated the earth’s movement.”

The secular critics’ story is one of the inexorable retreat of Christianity into the backwaters of social progress, and of its being left behind in the advancement of the knowledge enterprise. Consequently, one would have expected the Christian religion to wither at the margins of society and eventually go the way of the gypsies. But this has not been the case. It calls to mind Mark Twain’s remark, “The report on my death was an exaggeration.”

Perhaps it is time to take a fresh look at the trial of Galileo. The story of science discrediting the Christian faith took on the character of a dramatic myth that portrays a fallen hero or martyr for the great cause of reason (Galileo) in the face of tyrannical authorities defending the ignorance of religious dogma (represented by Pope Urban VIII and Robert Cardinal Bellarmine). Galileo, the icon of freedom of scientific inquiry, was crushed by an intolerant and oppressive religious system. The myth ends with a memorable one-liner protest attributed to Galileo when he blurted out after his recantation, “Eppur si muove” (“Yet it does move”).

But the truth is that the Galileo affair was not a battle between Christianity and science. It was a battle between old science (Aristotelian teleology) and new science (Galileo’s mathematical, mechanical science), in which entrenched university professors spared no quarters to protect their vested interests. Politics muddled the conflict as a weak Pope came under pressure to act tough against reformist movements.

Indeed, the fact that the ideas of Copernicus and Galileo found reception among the Protestants elsewhere in Europe where there was no centralized bureaucratic power belies the charge that Christianity is inherently hostile to free scientific inquiry. But given the persistent myth, it is necessary to go back to the beginning of the protean saga of the relationship between Christian faith and science to sift myths from historical facts.

The Historical Context

When Galileo offered a plausible (but not conclusive) defence to the alternative heliocentric universe proposed by Copernicus, he was not so much going against Christian theology as against the dominant Aristotelian-Ptolemiac model of the geocentric universe. The Ptolemaic model does work in explaining the irregular movements of the planets, albeit through introducing epicycles to the circular orbits of the planets and requiring cumbersome mathematical calculations to match what was observed in the heavens. Copernicus’ model may provide equivalent predictions of the movements of the planets, but it was not supported by adequate empirical evidence and in fact defied the common-sense experience of an immovable earth and moving stars and planets in the sky. The Copernican model remained controversial; or rather, it was tolerated as a helpful, though unproven hypothesis. There were not enough reasons then to discard a more or less working system that had reigned unchallenged for fourteen hundred years.

The heliocentric universe advocated by Galileo remained a speculative hypothesis that lacked corroborative evidence from empirical astronomical observations. The telescopes at that time were not sensitive enough to measure the parallax movements of the stars and no less an authority than Tycho Brahe (1541-1601) rejected Copernicus and favoured the old system as it provided an alternative explanation of everything that Galileo observed through his telescope.

Indeed, Copernicus’ system itself was plagued with inconsistencies as it continued to rely on the ancient idea of circular orbits for the sun. It was only much later that the heliocentric system provided simpler and more accurate calculations with the adoption of elliptical orbits proposed by Johannes Kepler. Even then Kepler did not provide compelling evidence to support the model and his astronomical tables were accepted so long as the heliocentric model was regarded as no more than mathematical calculations based on an unproven hypothesis.

The heliocentric universe advocated by Galileo remained a speculative hypothesis that lacked corroborative evidence from empirical astronomical observations. The telescopes at that time were not sensitive enough to measure the parallax movements of the stars; and no less an authority than Tycho Brahe (1541-1601) rejected Copernicus and favoured the old system as it provided an alternative explanation of everything that Galileo observed through his telescope. It was estimated that between 1543 and 1600 not more than ten astronomers accepted Copernicus’ system.[2]

It was granted that the Galileo/Copernicus theory was useful in requiring less complex mathematical calculations. But at that time mathematics was regarded as an inferior intellectual discipline that provided only technical calculations and could not be relied on to provide true explanations and insights into the world around us. Indeed, the pecking order for the academic disciplines in the universities put theology at the top, followed by philosophy (natural science), medical science and mathematics at the bottom. Hence the scholars who opposed Galileo could brush aside astronomers like him with the denigrating remark that astronomers were “merely mathematicians.”

Natural philosophy and physics did not use mathematics as it was considered incapable of grasping the essential qualities of objects in the real world. People just did not expect mathematics to provide an explanation of the true nature of things or their causes. Anyone with some basic understanding of mathematics would know it is only an ideal conceptual, mental exercise – for example, calculations of trajectories of projectiles ignore resistance and wind currents. The results may be useful for practical purposes, but the whole exercise is nonetheless an abstraction.

Galileo’s proposal itself failed to provide an explanation why the earth should be moving – an explanation that had to wait till Newton formulated the theory of universal gravitation in 1687. Galileo’s piecemeal astronomy was no substitute for Aristotle’s system as the latter’s explanation that the earth is the centre toward which all things naturally gravitate to as their resting place seemed a sensible natural explanation. Further, the Aristotelian teleological explanation for dynamic change offered a more comprehensive description of the world. To support his theory, Galileo suggested that the tidal phenomenon was due to the rotation of the earth as it orbits round the sun. But this explanation was no more than a conjecture. His critics could easily point out that his tidal theory would predict tides at their highest at noon (the time for greatest retardation) and lowest at midnight (the time of greatest acceleration) and this simply contradicted daily observations. Convincing proof for the rotation of the earth was provided only in the mid-1800s with the introduction of the Foucault pendulum.

Scientific Skirmishes

Scholars took offence at Galileo for transgressing the boundaries of academic disciplines. One would not think kindly of a physicist trying to explain medical illness or a logician trying to explain sociology (a similar modern phenomenon would be socio-biologists who are no less speculative in their theorizing when they transgress the disciplines of ethics and psychology). In the eyes of his contemporaries, mathematical astronomers like Galileo were merely technicians – not intellectuals, much less philosophers or theologians. To compound matters, what irked the university professors was the fact that Galileo the technician had wormed his way into the court of Medici in Florence and secured the appointment to the position of ‘court philosopher’. In effect, Galileo bypassed the proper procedure of going through the university system.

To add insult to injury, this Galileo had the audacity to challenge the reigning ideas of the academia (where new ideas were tested discreetly in the classroom) by publishing and disseminating his new-fangled ideas to the wider public. It did not help that Galileo was generally recognized to be the superior debater who humiliated his opponents with satirical wit and sarcasm in a series of disputes.[3]

In 1610, Galileo presented his telescope discoveries of mountains on the moon as refutation of the Aristotelian teaching that the heavenly bodies made of ‘quintessence’ must be perfectly spherical. He pointed out that the moon-like phases of Venus show that Venus orbits round the sun, contrary to the Ptolemaic system. Still, his opponents refused to take these observations seriously since there was no theory of optics at that time and Galileo himself was not able to explain how the telescope worked to produce such observations. Indeed, his opponents insisted that the observations were not of things in the heavens but optical illusions created by the lenses. Galileo pressed his case unrelentingly and in 1611 presented the existence of sunspots which refuted Aristotle’s teaching that the heavenly bodies which are made of unalterable ‘quintessence’ must be perfect and not subject to change

For Galileo the goal of conducting experiments was not to formulate theories but to provide a platform to test theories. The resulting observations and mathematical measurements would either confirm or refute the hypothesis under examination. In short, Galileo sought to demonstrate the inadequacy of Aristotelian teleological science and substituted it with a new science that combined rational intuition (idealized mathematical models) and experimentation. That is to say, Galileo’s goal was to demonstrate that his opponents had got their theories wrong because their methodology was inadequate and unreliable.

The real goal for Galileo was not to promote Copernicus; it was to champion a new scientific method to investigate nature, i.e. a unified science of mathematics, observation and empirical experimentation that was free from constraints represented by Aristotelian philosophy that restricted the study of nature. Such a scientific method seeks to apply reason to delineate the various causes for change and to determine the teleology or ultimate purpose of natural events.[4]

Galileo was careful to assure the authorities that his method was consistent with the Bible. In his Letter to the Grand Duchess Christiana,[5] the mother of his patron Cosimo II de’ Medici, he argued that astronomical theories should not be regarded as tenets of faith. It would be inappropriate to use the Bible, which is given in everyday language, to settle competing astronomical theories. In effect, his polemics sought both to offer a superior model for scientific investigation and free bible interpretation from an alien, historically contingent intellectual framework. For Galileo, purely scientific questions should be decided on their own merits, based on the best evidence available and are not to be confused with matters of faith.

Facts of the Trial[6]

Perhaps Galileo was overconfident about the persuasiveness of his intellectual arguments. But how could he expect a dispassionate and objective response when he himself poured scorn and sarcasm at his opponents? To make matters worse, university careers were at stake, and with it the coveted salaries, prestige and influence. Scholars attacked by Galileo would defend their interests at all cost. Indeed, the academic ‘Evil Empire’ did strike back. Galileo’s opponents formed a league, the Liga, under the leadership of Lodovico delle Colombe, to deal with the pretender – a mere mathematician pretending to lecture theologians on their own turf. When they failed to beat him in logical debates, they took the matter to the ecclesiastical court.

It was easy for them to trump up charges accusing Galileo of teaching heresy since Galileo’s system was premised on Copernicus’ system, which had already been proscribed by the authorities. The charges were cynically motivated but given Galileo’s pugnacious attacks it would be naïve to think he would be given a fair hearing. It also didn’t help that Galileo had publicly offended the Pope by portraying him as an ignorant simpleton in his book Dialogue Concerning the Two Chief World Systems.

Galileo was summoned to the ecclesiastical court where he denied that he was teaching Copernicus’ system and protested that he was using Copernicus only as a hypothetical test case. But the court was not persuaded as it was clear to the reader of the book Dialogue that Galileo was out to present a convincing case for Copernicus’ system. In the end, the court found Galileo “vehemently suspect of heresy.”

Galileo pleaded for mitigation in judgment – asking that the court still acknowledged that he was a good Catholic and that he did not deliberately deceive his readers especially since he had obtained licence to publish the Dialogue. Upon receiving these concessions Galileo knelt and confessed aloud to the court,

I have been judged vehemently suspect of heresy, that is, of having held and believed that the Sun is the centre of the universe and immovable and that the Earth is not the center of the same, and that it does move…I swear that in the future that I will neither say nor assert orally or in writing such things as may bring upon me similar suspicion.

Undoubtedly, the trial and judgment of Galileo is one of the embarrassing episodes in church history when theologians, acting out of professional jealousy and personal animosity, found it expedient to silence an intellectual genius. It was laudable that Pope John Paul II in 1992 sought to correct the error of the Church. He declared,

Thanks to his intuition as a brilliant physicist and by relying on different arguments, Galileo, who practically invented the experimental method, understood why only the sun could function as the centre of the world, as it was then known, that is to say, as a planetary system. The error of the theologians of the time, when they maintained the centrality of the Earth, was to think that our understanding of the physical world’s structure was, in some way, imposed by the literal sense of Sacred Scripture.

The Pope publicly apologized for the error of the church in the year 2000 – an act that demonstrates that though not infallible, nonetheless the Church possesses within itself the resources and intellectual integrity to undertake self-critique and reform.

Several caveats should be also noted here. First, there is no record that Galileo blurted out in protest – “Eppur si muove” (“And yet it does move”) after his judgment. Regardless of Galileo’s abrasive and arrogant character, he knew better than to exacerbate a bad situation. He knew the chips were down for him and was quick to ask for leniency and was leniently treated subsequent to the trial.

Second, the historical records do not support the myth that Galileo was rigorously interrogated à la grand inquisition style (torture). Galileo was treated with respect and was allowed to lodge at the Tuscan embassy until the trial began, whereupon, he was transferred to the prosecutor’s apartment accompanied by a servant. Galileo was transferred to the palace of the grand duke of Tuscany after being sentenced. He was then hosted for five months (albeit under house arrest) at the residence of his friend, the archbishop at Siena. The Pope eventually allowed Galileo to return to his farm at Arcetri near Florence and provided him with pensions until his death in 1642.

Finally, the dramatic myth of conflict between science (Galileo) and oppressive religion (the Inquisition) indeed stands as an aberration alongside the more mutually supportive relationship between Christian authorities and scientists throughout Christian Europe. Galileo evidently continued to enjoy support for his scientific work from important leaders of the Catholic Church. Christians elsewhere, especially among the Protestant countries had no problem with either Copernicus or Galileo. Indeed, recent historiography of science, represented by scholars like Robert K. Merton, Herbert Butterfield, R. Hookyas, Stanley Jaki, Colin Russell and James Hannam, emphasize the vital role Christians played in the advancement of modern knowledge through empirical investigation and experimentation.[7] It would be claiming too much to say that Christianity was solely responsible for the rise of modern empirical science. But it is certainly misleading to focus on the trial of Galileo as the determinate event in the interaction between Christianity and modern science.

That modern science was built on the Greek legacy of rational thought and mathematics cannot be denied. At the same time, it should be stressed that it took the Christian doctrine of creation to liberate society from a deified view of nature that inhibited empirical study of nature. Greek mathematics and Greek rationality (mediated by Arabic philosophers to Medieval Europe) were crucial factors that contributed to the rise of modern science. But by the same token the Greeks were trapped by their over reliance on reason. H. D. F. Kitto noted that to the Greeks nature was both rational and knowable through reasoning, “The Greek never doubted for a moment that the universe is not capricious: it obeys Law and is therefore capable of explanation.”[8] But this faith in reason was so exaggerated that the Greek “tended to impose pattern where it was in fact not to be found, just as he relied on Reason where he would have been better advised to use observation and deduction.”[9]

Greek society was built on slave labour and as such manual labour was regarded with disdain. Aristotle’s justification for investigation was to satisfy curiosity rather than to master nature and therefore relied on a priori reasoning. There was no need to change the world. Indeed, since nature shares a divine nature, the focus was on discovering the teleological reasons for natural phenomena, by relying on rational intuition and deduction rather than careful observation corroborated with experimentation that characterizes modern science.

It cannot be denied that the Greeks provided essential tools of logic and mathematics for the development of science, but in restricting themselves to reason, Greek science could only stagnate. The dominance of Aristotelian science was a testimony to its comprehensive explanatory goals, but inertia set in with untested and therefore inadequate theoretical explanations that led to complacency and stagnation in knowledge.

The dynamism of modern science was achieved when Greek rationality was supplemented with the Judeo-Christian doctrine of creation. On the one hand, the Christian doctrine of creation relativizes nature from a deified (and untouchable) status. On the other hand, because nature is regarded as a product of God, it is both an orderly and dependable world. But the orderly mechanism by which nature operates is to be discovered not through fallen (and hence limited) reason, but through experience and experimentation.

Whereas for the Greek the workings of nature were rationalistic and purposive (since purposefulness is inherent within nature itself), in the Hebrew-Christian tradition purpose resides in God, not in nature. If man seeks to discover the patterns of order in nature he must resort to experience, for he cannot discover them by intuition or reason alone. The early-modern Christians adopted a chastened confidence in reason which should not be regarded as an infallible god. Likewise, for them the quest of science is not to produce absolute truth – it is just a human enterprise that systematically investigates into divine ‘revelation’ in nature.

M. B. Foster suggests succinctly that the Christian doctrine of creation provides the fundamental presupposition for the emergence of modern empirical science:

The reliance upon the sense for evidence, not merely for illustration, is what constitutes the empirical character peculiar to modern natural science… Modern…natural science could begin only when the modern presuppositions about nature displaced the Greek (this was, of course, a gradual process, but its crisis occurred at the date of the Reformation); but this displacement itself was possible only when the Christian conception of God had displaced the Pagan, as the object (not merely of unreasoning belief, but) of systematic understanding.[10]

To summarize, modern empirical science flourished when the mathematical rationality exemplified by Galileo and Kepler was supplemented with the empirical experimental method of Francis Bacon and Robert Boyle.[11] It should be stressed that the new historiography of science does not seek to minimize the important contribution from the Greeks, but to recover the crucial role played by Christianity in the rise of modern science without ignoring the rich and multifaceted, sometimes mutually supportive and sometimes conflicting relationship between science and Christianity. The nuanced and protean relationship should not surprise us given the tentativeness of scientific knowledge complicated by the human foibles of scientists and theologians that include academic rivalry and vested interests and intense competition for financial patronage.[12]

But the findings of the new historiography of science with its overall positive assessment of the interaction between Christianity and science ought to alert us to the incongruity of elevating the Galileo trial to epitomize the fatal defeat of Christianity in its ‘warfare with science’. Indeed, it would be ironic for science, with its insistence on verifiable facts, to perpetuate myths about the Galileo affair that are without historical foundations.

**A fuller version of this article was published in Church & Society in Asia Today 15 (Aug 2012), pp. 113-127.

Publisher: Centre for the Study of Christianity in Asia, Trinity Theological College, Singapore.



[1] Bertrand Russell, History of Western Philosophy, 2nd ed. (London: Allen & Unwin, 1961; Oxford: Routledge reprint, 1995), 520.

[2] Robert S. Westman, “The astronomer’s role in the sixteenth century: a preliminary study”, History of Science 28 (1980): 105-147. Westman writes: “most sixteenth century astronomers understood, then, that by inspecting each of Copernicus’s planetary models one could convert the motions of the geokinetic-heliocentric framework into those of the observationally equivalent geostatic-heliokinetic framework frame.” 106.

[3] For a straightforward narrative of Galileo’s disputes with the university professors see Charles Hummel, The Galileo Connection: Resolving Conflict Between Science and the Bible (Downers Grove: Inter-Varsity Press, 1986).

[4] For Aristotelians, all changes in nature could be adequately explained by material, formal, efficient and final or purposive causes.

[5] Galileo, Discoveries and Opinions of Galileo, translated by Stillman Drake (New York: Anchor Books, 1957), 173-216.

[6] For a brief and accessible entry, see Stillman Drake, Galileo: A Very Short Introduction (Oxford: Oxford University Press, 2001). Drake noted that the philosophers of Aristotelian science that focused on causes initiated charges against Galileo for championing a new science that focused on framing mathematical-mechanistic laws. William R. Shea and Mariano Artigas, Galileo in Rome: The Rise and Fall of a Troublesome Genius (New York: Oxford University Press, 2003) provides a readable narrative sensitive to the nuances between Galileo and a divided Church leadership. Pietro Redondi, Galileo Heretic (Princeton: Princeton University Press, 1987) notes that Galileo’s opponents accused him of heresy since his nominalist and atomist philosophy considered sensible phenomenon (colour, tastes, sounds) as subjective experience rather than intrinsic qualities of objects. This view would undermine the objective distinction between the substance of Christ’s body and blood and the equally real properties of bread and wine. The accusation was an expedient charge; but it was, fortunately, not taken seriously by the Pope.

[7] See Robert K. Merton, “Puritanism, Pietism and Science,” in Sociological Review 28 (1936), reprinted in Robert K. Merton, Social Theory and Social Structure (New York: Free Press, 1957), 574-606. Herbert Butterfield, Origins of Modern Science 1300-1800 (Kent: Bell Publishing,1950), R. Hookyas, Religion and the Rise of Modern Science (Grand Rapids: Eerdmans, 1978), Stanley Jaki, The Road of Science and the Ways of God (Chicago: University Chicago Press, 1978), Colin Russell, Cross-currents: Interaction between Science and Faith (Grand Rapids: Eerdmans, 1985) and James Hannam, The Genesis of Science: How the Christian Middle Ages Launched the Scientific Revolution (Washington, D.C.: Regnery Publishing, 2011). Robert Merton continues to attract much debate because he supported the thesis that the Puritans played a disproportionate and decisive role in the development of modern science with quantitative empirical analysis. The more significant voices in the debate are conveniently collected in I. Bernard Cohen, ed., Puritanism and the Rise of Modern Science: The Merton Thesis (Chapel Hill: Rutgers University Press, 1990).

[8] H. D. F. Kitto, The Greeks (New York: Penguin 1951), 176. Kitto elaborates, “Here we meet a permanent feature of Greek thought: the universe, both the physical and the moral universe, must be not only rational, and therefore knowable, but also simple; the apparent multiplicity of physical things is only superficial.” The Greeks, 179.

[9] Kitto, ibid., 187

[10] See M. B. Foster’s classic article, “The Christian Doctrine of Creation and the Rise of Modern Natural Science,” in Mind 43 (1934), reprinted in C. A. Russell ed., Science and Religious Belief. A Selection of Recent Historical Studies (London: Hodder & Stoughton, 1973), 294-315. R. Hookyas concurs, “The biblical conception of nature liberated man from the naturalistic bonds of Greek religiosity and philosophy and gave a religious sanction to the development of technology that is, to the dominion of nature by human art.” Religion and Rise of Modern Science, 74.

[11] Robert Boyle observed: “Thus the universe being once framed by God and the laws of motion settled and all upheld by his perpetual concourse and general providence; the same philosophy teaches, that the phenomena of the world are physically produced by the mechanical properties of the parts of matter, and that they operate upon one another according to mechanical laws. ‘Tis of this kind of corpuscular philosophy that I speak.’” Quoted in Hookyas, Religion and Rise of Modern Science, 62-63.

[12] Colin Russell in his book Cross-currents aptly exploits the metaphor of the ebb and flow, the cross-currents of the river to describe the protean relationship between Christianity and science: (i) Springs of Mount Olympus Greek science, (ii) Copernican watershed, (iii) Converging streams of science and biblical ideology, (iv) Deepening waters of Scientific Revolution, (v) Harnessing the river of science, (vi) Temporary Flood with new geology, (vii) Troubled waters of evolution, (viii) Sacred stream of Romantic scientific naturalism, (ix) Powerful currents of Newtonian physics, (x) Polluting effluence of science and environment and (xi) Floodtide of nuclear science.

Leave a Reply

* Copy this password:

* Type or paste password here:

174,903 Spam Comments Blocked so far by Spam Free Wordpress