Why the Pre-Copernican Cosmological Revolution Was Not a Revolution

Vistas in Astronomy, Vol. 39, pp. 513-519, 1995 Copyright @ 1996 Elsevier Science Ltd

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Why the Pre-Copernican Cosmological Revolution Was Not a Revolution?

A. G. Pacholczyk Steward Observatory, University of Arizona, Tucson, AZ 85721, U.S.A.

Abstract: The ‘scientific component’ of the Copernican cosmological revolution followed a seemingly minor local structural change (consisting of the transposition of the Earth and the Sun), initially not affecting the global Platonic- Aristotelian spherical symmetry of the Universe and the general arrangement of astronomical bodies at sufficiently large distances from its center. Yet this change resulted in a rich ‘ideological component’ of the Copernican revolution in the Popperian sense; the importance of this ideological component is generally regarded as a consequence of the tensions arising from apparent contradictions between the new cosmos and several Scriptural passages (as if the previous Platoni+Aristotelian cosmos were in perfect agreement with the Scriptures, which certainly was not the case). The scientific component of the pre-Copernican cosmological revolution (replacing the plane-parallel scriptural cosmos with the spherically symmetric non-scriptural Universe of Plato and Aristotle), was a major global change in the large-scale structure of the Uni- verse. This change took place at different times in different places in Chris- tendom, and was by no means ideologically revolutionary: the pre-Copernican revolution had a very insignificant ‘ideological component’. In this paper, after examining this transition in more detail, we shall ask the pertinent question: why did the pre-Copernican cosmological revolution not have any significant ‘ideological component’? If the God-created Universe could be depicted in the opinion of the majority of Church Fathers and Schoolmen by the (non- scriptural) spherically symmetric Platonic or Aristotelian model as well as by the (scriptural) tabernacular Babylonian model, then why couldn’t it be described just as well in the opinion of 17th century churchmen by the (also non- scriptural) Copernican model? The paper suggests that the tentative answers to these questions are provided by different anthropocentric ramifications of respective cosmologies which determine the differerence between the ideological components of the two cosmological revolutions. At the time of the Coperni- can revolution, there was no conceivable alternative to a geometric conceptualization of mankind’s centrality in the Universe. That is why geometric decentralization was fought against with such intensity. It took three centuries and a radically different cosmological paradigm to find another (anthropic) form of understanding this centrality, after it was seemingly lost for such a long time.

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According to Popper, a revolution in science may have two components: a ‘scientific component’ and an ‘ideological component.’ l The scientific component is the process of replacing a well-established theory with a new theory. The ideological component is the sum of “all processes of ‘social entrenchment’ or perhaps ‘social acceptance’ of ideologies, including even those ideologies which include some scientific results.” *

These two components of a scientific revolution are distinct. It is possible to have a scientific revolution with a revolutionary scientific component and no ideological component (e.g. the introduction of quantum mechanics). It is also possible to have the opposite situation: a cumulative scientific change expressed through technological advances may induce societal hostility toward science (misidentified with technology). Examples of such hostilities are a call for the ‘moratorium on science’ resulting from ‘technological unemployment’ during the Great Depression, the anti-nuclear movement, or the radical environmentalists’ opposition to scientific advances. 3

Looking at ideological components, we see that one of the most dramatic revolutions in science was the Copernican cosmological revolution. It geometrically decentralized man in the Universe, and this had well-known consequences for religious Weftanschauung and for the expansion of secularism. The subsequent bursting of the firmament and the scattering of fixed stars throughout infinite space, first illustrated by Thomas Digges in his famous woodcut, 4 accelerated the process. For the next three centuries man was an entirely irrelevant entity, a mere speck near a star in a universe that was filled with an infinity of stars.

Discussing the aftermath of the Copernican revolution in “Galileo and the Council of Trent: The Galileo Affair Revisited” Olaf Pedersen writes:

. ..we can provide a rather precise answer to the first important question, “What happened?“, although there may still be one or two obscure points concerning the proper understanding of the mere historical facts. Also the second question, “How did it happen?‘, is now much better understood than before. Only the third question, “Why did it happen. 7”, still divides scholars and others to such an extent that no one can pretend that even an approximate solution has been reached. ’

Pedersen reviews several available classes of answers to the third question: “why did it happen?” The first answer consists of pointing out the inevitability of such conflicts which result from essential incompatibility between science, based on rational inquiry, and religion, based on allegedly irrational belief in revealed truth. 6 ’ 8 The second answer goes along Marxist lines and identifies as the reason for the conflict the change of Christian ideology from being ‘progressive’ during the epoch of feudalism to becoming ‘reactionary’ when feudalism was yielding to early capitalism. g The third answer identifies the reason for the conflict as

i Karl R. Popper (1975) The rationality of scientific revolutions. In: Problems of Scientific Revolution: Progress and Obstacles to Progress in the Sciences (The Herbert Spencer Lectures, 1973), R. HarrC (ed.), pp. 72-101. Clarendon Press, Oxford. z Ibid., p, 88. J I. Bernard Cohen (1985) Revolution in Science, p. 17. Harvard University Press, Cambridge, MA. 4 Thomas Digges (1576) A Perfit Description of the Caelestiall Orbes. Thomas Marsh, London. s Olaf Pedersen (1983) Galileo and the Council of Trent: the Galileo affair revisited. Studii Gafileani, Vatican Observatory Publications: Vatican City State 1, l-29. s Andrew D. White (1896) A History of the Warfare of Science with Theology in Christendom, volume 1. Dover Publications, New York (1960). ’ A. Wolf (1959) A History of Science, Technology and Philosophy in the 16th and 17th Centuries, volume I, 2nd edn. Harper & Brothers, New York. s J. D. Bernal (1954) Science in History, London. 9 P. L. Kapitza (1981) In: The Impact of Modern Scient$c Ideas on Society: In Commemoration of Einstein, C. M. Kinnon (ed.), pp. 52-53. D. Reidel Publishing Company, Dordrecht.

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resulting from the ‘pastoral’ need of temporarily suppressing a disturbing truth for the good of the souls. l The fourth is given as a string of particular circumstances related to Galileo and his interaction with the scientific establishment. *

Pedersen provides a convincing critique of all the above reasons for the conflict between Galileo and the Church and suggests his own answer to the “Why did it happen?” question. To him the conflict could be understood as a “consequence of the cramped and strained attitude by which the Church tried to bring her own house in order after the onslaught of the Reformation” after the Council of Trent , which “seemed to have so changed the criteria of truth that the power of deciding the truth or falsehood of a scientific idea was taken away from the community of scholars and conferred upon a bureaucratic institution in Rome”. 3 Pedersen argues that “the Copernican hypothesis was a matter of very little importance” to the Holy Office “in comparison with the apparent necessity of upholding a ‘literal’ interpretation of the exegetical principles of the Council,” and concludes that the Galileo affair was not about astronomy, but about the Council of Trent. 4

The Council of Trent during its 4th Session approved two decrees concerning the notion of tradition, the content of the canon and the matters of edition and interpretation of the Scrip- tures. Richard J. Blackwell discusses in detail the ramifications of these decrees for the Galileo affair. 5 Blackwell argues that the 1616 condemnation of Copernicanism was arrived at by confronting the new cosmology with the Sacred Scripture accepted and interpreted strictly “according to that sense which Holy Mother Church has held and does hold, to whom it belongs to judge of the true meaning and interpretation of the Sacred Scriptures,” and not accepted or interpreted “otherwise than according to the unanimous consent of the Fathers”. 6 We will recall later in this paper that the acceptance of the spherically symmetric pre-Copernican cosmology by the Fathers was slow and tortuous, yet that entirely non-Scriptural picture of the world became the official cosmology of the Church in the high Middle-Ages. It also was accepted by the Reformers alike. There must have been more to the local structural differences between the two cosmologies: that difference alone rather than any global characteristic of either of the two universes had to be perceived as de$de.

Looking at the overall structure of the Universe, it was a rather minor event that started the Copernican scientific revolution: the transposition of the Earth and the Sun. This change did not initially affect the global structure of the Universe, which retained its spherical symmetry and its general arrangement of astronomical bodies at sufficiently large distances from its center. Yet this seemingly minor structural change of the cosmos resulted in a rich ‘ideological component’ of the Copernican revolution, in the Popperian sense; the importance of this component is generally regarded as a consequence of the tensions arising from apparent contradictions between this transposition and several Scriptural passages (mainly Joshua

’ John Henry Newman (1877) Via Media, 3rd edn, pp. Iv-&i. London. z Giorgio de Santillana (1955) The Crime of Galileo. University of Chicago Press, Chicago. j Pedersen, op. cit., p.24. 4 Ibidem. s Richard J. Blackwell (1991) Galileo, BeNurmine and rhe Bible. University of Notre Dame Press, Notre Dame. ’ Pope Pius IV (1863) Bull ‘Iniunctum nobis’ (13 November 1564). In: Enchiridion symbolorum, definitionurn, et declarationurn de rebus fidei et mown. H. Denzinger and Schoenmetzer (eds), 32nd edn. Herder, Freiburg im Breisgau (1963). English translation in: The Christian Faith in the Doctrinal Documents of the Catholic Church (1982), J. Neuner and J. Dupuis (eds). Alba House, New York.

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10: 12, 1 Psalms 19:5-6 and 104:5, Ecclesiastes 1:4-6, * and Job 9:6, 3 all of which refer to either the immobility of the Earth and/or to the motion of the Sun). The Reformers and, later, the Catholic Church reacted against Copernicus’ innovation; the severity of their reaction leaves the impression that the previous cosmological model was in perfect agreement with the Scriptures. Nothing could be further from the truth: the Eudoxian-Aristotelian and Ptolemaic cosmological systems were at odds with the entire first Chapter of Genesis and with numerous passages in Psalms and other parts of the Scriptures. Everybody knew it, yet the spherically symmetric cosmos had been firmly accepted by both the Church (since the 10th century 4 ) and the Reformers.

The scientific component of the pre-Copernican cosmological revolution, replacing the plane-parallel Babylonian cosmos with the spherically symmetric Universe of the Pythagore- ans and Plato, was a major global structural change in our views of the Universe. The flat Earth floating on the ocean was replaced by a spherical Earth containing some waters on its surface. The flat or tent-like heavens holding heavenly waters were replaced by waterless, spherically layered heavens; one of its layers was an icy crystalline sphere. One could no longer fall off the edge of the ocean into an abyss: the absolute up and down became an up and down that was relative to the center of the Universe, which coincided with the center of the spherical Earth.

The Babylonian model of the Universe 5 was the one used throughout the Sacred Scrip- tures. 6 It was essentially a plane-parallel model: a flat Earth floating on an ocean, and beyond the ocean’s edges lay an abyss. The pillars supporting the Earth stretched deep into the abyss. The whole world was covered by a vault (firmament) which separated the waters above the firmament from the waters (ocean) below it. The tent-like tabernacular Universe of rectan- gular shape, derived from this Babylonian model and from Scriptural passages, was popular for some time in the early Middle Ages in the East. Its popularity reached its zenith when an Egyptian monk, Kosmas Indicopleustes, described its details in ‘The Christian Topography’ (535). ’ It is interesting to note that this tabernacular Universe model was believed to be only allegorical by the Alexandrians. Clement of Alexandria (c. 200) suggested an allegorical interpretation of the world based on the Tabernacle and its furniture, a while Origen (185-254) interpreted the separation of waters by the firmament as a spiritual separation of us from evil. g Nestorians, however, accepted this Universe as a real model, as Plotinus said about Diodorus, bishop of Tarsus (d. 394), and Johannes Philiponus wrote about Theodore, bishop of Mopsuestia in Cilicia (d. 428).

I This was first pointed out by Luther in 1539, cf. Martin Luther: Tischreden, Weimar: H. Bohlaus, 1912-1921, volume IV, no. 4638. 2 This was pointed out by Christopher Clavius: “In spheram Ioannis de Sacro Bosco commentarius” (1570) In: Opera methematica. Moguntinae, 191 I-1912, volume III. 3 This was pointed out and interpreted in favour of Copernicanism by Diego de Zuiiiga of Salamanca. In: Commentary on Job. Toledo, 1584. English translation in: Richard J. Blackwell (1991) Galileo, Bellurmine and the Bible, appendix II, pp. 185-186. University of Notre Dame, Notre Dame. 4 From about the 9th century and most definitely since the pontificate of Sylvester II (999-1003), cf. J. L. E. Dreyer (1953) A History of Astronomy from Thales to Kepler, chap. X. Dover Publications, New York. s Thorklid Jacobsen (1957) Enuma Elish - ‘The Babylonian Genesis’. In: Theories of the Universefrom Babylonian Myth to Modern Science, M. K. Munitz (ed.), pp. 8-20. The Free Press, Glencoe. 6 For analogies and differences between the Babylonian creation story Enuma elish and the creation in Genesis 1 see: Stanley L. Jaki (1992) Genesis I Through the Ages, chap. 1. Thomas Moore Press, London. 7 Kosmas Indicopleustes (1897) In: The Christian Topography of Cosmas, an Egyptian Monk, J. WE. McCrindle (tr. and ed.). Hakluyt Society, London. Cosmas Indicopleustes (1968-l 970) Topographiechrttienne. (Sources chritiennes, Nos 141 and 159). Editions de Cerf, Paris. ” Clement of Alexandria: Strom&cl, 1. V, cap. 6. y Origen (1733) In Genesim Homiliae. In: Opera, Delarue (ed.), volume II, Paris. Homilies on Genesis and Exodus (1982) R. E. Heine (tr. and ed.). The Catholic University of America Press, Washington.


The Biblical plane-parallel Universe gradually gave way to the spherically symmetric Pythagorean-Platonic cosmos throughout the early Middle Ages. ’ 2 Two main cosmological problems were extensively discussed throughout the period of this transition: the presence of waters above the firmament, and the existence of the antipodes. Basil the Great (c. 360) introduced the interpretation of supercelestial waters as a cooling agent to screen the world from the heat of celestial fire (the ‘outer fire of Olympus’ ). 3 Cyril of Jerusalem 4 stressed the reality of the waters, while Severianus, bishop of Gabala, Ambrose, bishop of Milan (d. 397) and Augustine, bishop of Hippo (354-430), affirmed their cooling effect, suggested by Basil. Ambrose discussed stability problems encountered when liquid water extended over a spherical firmament, ’ but Augustine pointed out that those waters could be vapors lighter than the clouds, 6 and Venerable Bede (c. 673-c. 735) suggested that they could be ice.’ After the debates died down, what was left of the supercelestial waters was the 9th heaven, a crystalline sphere located between the stellar firmament and the primum mobile made of ice rather than fluid, as Aquinas wrote. 8

The question of the antipodes was almost always addressed when discussing the sphericity of the Earth. Much had been written about the impossibility of walking upside-down, particularly by the adherents of the tabernacular model of the Universe with its absolute concept of up and down. However, the authors who accepted the Earth’s sphericity were concerned with the lack of evidence of the antipodes’ inhabitance; they debated whether the antipodes were even covered by dry land above the ocean. g The possibility of the antipodes’ being inhabited was clearly argued for by Virgilius, bishop of Salzburg (d. c. 785).

The spherical shape of the Earth and the heavens was affirmed by Basil the Great, Ambrose, Augustine, Isidorus Hispalensis (c. 570-636), Venerable Bede, and others; this view became generally recognized in the West by the 9th century and firmly established after the pontificate of Pope Sylvester II (999-1003). Duhem lo points out that John Scotus Erigena (833-880) and his followers, Pseudo-Bede (9th century) and William of Conches (12th century), advocated a modified Heraclidean Universe, which was a forerunner of the Brahean cosmos. Erigena wrote: “I want to talk about Jupiter, Mars, Venus and Mercury, which, incessantly, circulate around the Sun”. l1 l2 Several Roman encyclopedists in the 4-5th centuries (Chalcidius, l3

i For historical details of this transition see J. L. E. Dreyer (1906) History of the Pkmetary Systems from Thales to Kepler, ch ap. IO. Cambridge University Press, Cambridge. 2 See also Stanley L. Jaki (1992) Genesis I Through the Ages, chap. 3, pp. 70-108. Thomas Moore Press, London. J St Basil the Great (1721) Homiliae novem in Hexameron. In: Opera omnia, volume I. Garnier, Paris. Exegetic Homilies (1963), A. C. Way (tr.), homily 3,3. The Catholic University of America Press, Washington. 4 Cyril of Jerusalem (1703) Catechesis. Opera, IX, p. 116. Oxford. s St Ambrose (1704) Hexuemeron, 11.3, Col. 26, Paris. Hexameron. Paradise, and Cain and Abel (1961) J. J. Savage (tr.), homily I, pp. 23, 72. Catholic University of America Press, Washington. s St Augustine (401405) De Genesi ad liiieram libri duodecim, book II, chap. 5. The Literal Meaning of Genesis (1982) J. H. Taylor (tr.). Newman Press, New York. ’ Bede the Venerable (1848) De natura rerum. In: Venerubilis Bedue Opera, Giles (ed.), volume VI, chap. VII, London. s St Thomas Aquinas (1967) Summa Theofogiue, W. A. Wallace (tr. and ed.), volume 10, p. 81, London. ’ St Augustine (1924) De civitnte Dei Contra Pagunos, J. E. C. Weldon (ed.), book XVI, chap. 9. The Macmillan Co.. York. The Works of Aurelius Augustine: A New Translation, volumes I and II: The City of God, M. Dods (tr. and ed.), pp. 1871-1872. T. and T. Clark, Edinburgh. “‘P. Duhem (1913-1959) Le SystPme du Monde - Histoire des Doctrines Cosmologiques de Plato ci Copernic, volume III, p. 1 IO. Hermann, Paris. ” John Scotus Erigena (1853) De divisione naturae. In: Patrologia Latina, Migne (ed.), volume 122, cols 439-1022, Paris. Quoted after Duhem, op cit. r2 In the Hera&dean model only Mercury and Venus orbit the Sun. is Plato Timaeus a Calcidio translatus commentarioque instructus, J. H. Waszink and P J. Jensen (eds), London, 1962.

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Macrobius, ’ and Martianus Capella 2 ) described the Heraclidean model; through their works the model was kept alive indeed, Duhem is of the opinion that the majority of writers on astronomy between the 9th and 12th centuries were familiar with the Heraclidean cosmological model. 3 With the rediscovery of Euclid, Aristotle and Ptolemy, the spherically symmetric Aristotelian Universe replaced all other models of the Universe (Scriptural or Greek, Her- aclidean included), and it became the official, although non-Scriptural, cosmological model of the Church. 4 While there was much controversy about motion and the Celestial Movers, about Eudoxian spheres and Ptolemaic eccentrics and epicycles, and about Aristotelian philosophy in general and physics in particular, there was no quarrel with the overall structure of the model Universe. The controversy about Aristotelian philosophy and physics culminated in the 1277 (and 1284) condemnations of the Averroistic version of Aristotelianism in Paris and Canterbury. Among the 219 articles that were condemned not a single one refers to the Uni- verse’s spherical symmetry or any other non-Biblical property. 5 Indeed, even Arthur Koestler, who cannot be accused of any sympathy towards the Church, admits that he is “not aware of any recorded instance of a cleric or layman being indicted for heresy in this heresy-ridden age because of his cosmological views”. 6

We have traced briefly the transition from the tabernacular plane-parallel Babylonian model to the spherical Platonic and Aristotelian cosmos. As we did it, one major point became clear: this transition took place at different times in different places in Christendom, and was by no means revolutionary: the pre-Copernican revolution had a very insignificant ‘ideological component’.

We should therefore ask the pertinent question: why did the pre-Copernican cosmological revolution not have any significant ‘ideological component’? The tentative answer to this question is that the transition from the Babylonian to the Aristotelian Universe did not appreciably affect any of the important religious messages carried in the Sacred Scriptures. God could have as well created an Aristotelian or, for that matter, a Ptolemaic Universe rather than the Babylonian.

It has been argued that in the literary genre used in Genesis 1 the creation message refers to the totality of things, whatever they are, and whatever their internal structure might be. ’ The Old Testament description of the Babylonian Universe is quite fragmentary:

The Old Testament leaves undefined the outer confines of the waters above the firmament and is equally unconcerned about speculating on what held together the waters on which the Earth was resting and very firmly at that. The only real specific in the biblical world view, the world-tent, had around it an aqueous envelope whose boundary was not specified even to the extent of being called an envelope. 8

The Universe is referred to as a whole by listing its constituent parts. This description uses the familiar “method of conveying the whole by reciting its essential parts as well as the chief constituents of each part,” and emphasizing “that dynamic aspect of the world view of Genesis

’ Commentary on the dream by Scipion, W. H. Shah1 (tr. and ed.), verse 422, New York, 1952. 2 De nuptiis philologiae et Mercurii. E Eyssenhardt (ed.), Leipzig, 1866. Partially translated in A Source Book in Medieval Science, E. Grant (ed.), Cambridge, MA, 1974. 3 Duhem, op. cit., volume III, p. 110. 4 See e.g. Edward Grant (I 978) Cosmology. In: Science in the Middle Ages, David C. Lindbergh (ed.), pp. 265-302. University of Chicago Press, Chicago. s For the list of condemned propositions see Ernest L. Fortin and Peter D. O’Neill (tr.) (1963) In: Medieval Political Philosophy: A Sourcebook, Ralph Lerner and Muhsin Mahdi (eds), pp. 335-354, Toronto. ’ Arthur Koestler (1959) The Sleepwalkers, p. 93. Grosset and Dunlap, New York. ’ Jaki: op. cit., chap. 8. R Jaki: op. cit., p. 284.


1, namely, its being about an all that may forever remain the Creator’s privilege to know in a strict sense even in its measurable properties.” l

If the Old Testament refers to the Universe as a more or less unspecified whole, which could be depicted easily by either the Aristotelian or Babylonian models, then why couldn’t this whole, this totality of things, be described just as well in the opinion of 17th century churchmen by the Copernican model? It could, provided such a change of model would have no bearing on any of the religious messages contained in the Scriptures; however, unlike the pre- Copernican cosmological revolution, this was not the case. And the 17th century churchmen knew it. Although the global properties of the Copernican and Aristotelian Universes were initially the same, the transposition of the Earth and the Sun would decentralize both the Earth and the human race and thus seemingly put in question the Biblical message of the cosmic relevance of human beings. One may argue that being transposed to the ‘third heaven’ was to be closer to the Empyreum - closer to God - but at that stage it was no longer the Aristotelian conception of the Universe that determined cosmic meaning in this controversy, but a post- Diggesian cosmic irrelevance in an infinite Universe. 2

The issue of centrality of mankind in the God-created Universe was the key difference between the two cosmological revolutions and their respective ideological components. At the time of the Copernican revolution, there was no conceivable alternative to a geometric conceptualization of this centrality. That is why geometric decentralization was fought against with such intensity. It took three centuries and a radically different cosmological paradigm to find another, anthropic 3 form of understanding this centrality, after it was seemingly lost for such a long time.

’ Jaki: op. cit., p. 293. z Francis R. Johnson (1937) Astronomicni Thought in Renaissance Engfund, pp.161-169. Johns Hopkins University Press, Baltimore. 3 cf eg. B J. Carr and M. J. Rees (1979) The Anthropic Principle and the structure of the physical world. . . . Nature 278, 605-612, or John D. Barrow and Frank J. Tipler (1988) The Anthropic CosmologicalPrinciple. Oxford University Press, Oxford.