Published in Nuremberg in 1543 the De Revolutionibus Orbium Coelestium by Nicholas Copernicus[1] ranks with Ptolemy's Almagest, Newton's Principia, and Darwin's Origin of Species as signifying the opening to an epoch in the history of scientific thought. The forthcoming Scientific Revolution of the seventeenth century is marked off from medieval science by this work though it was not received as such at the time and its effects were not immediate. Far from the work being ‘ahead of its time’, there were no technical reasons why the book could not have been written at any time since Ptolemy in the 2nd century A.D.
There is no doubt that the intellectual climate fostered in the Reformation was effectual in Copernicus's decision to publish and it had long been acknowledged that the Julian calendar required revision. This was due to the very slight difference between the mean solar day and the sidereal day (measured against the fixed stars) which had led to a discrepancy of some ten days by the sixteenth century. Providing a basis for reform of the calendar was one of his aims set out in the Revolutions. It is equally certain that the good Catholic paved the way for the mainly Protestant Scenic Revolution, chiefly in the works of Descartes, Galilei, Huygens, and Newton.
Copernicus (c.1473-1543) provisionally settled many astronomical questions until more and better information was produced; he showed way towards tackling others; and cleared away much of the cosmological bric-à-brac that had accumulated since the time of Ptolemy (c.100-c.165 A.D.) in trying to ‘save the phenomena’', that is, reconciling observed anomalies in the planetary system. The single most important ingredient the treatise was to establish the Sun at the centre of our universe, albeit circular planetary orbits rather than elliptical as Kepler was to determine 1609. The central problem of medieval astronomy concerned the ‘irregular paths’ of the planets (from the Greek for ‘wanderer’) and Copernicus reconstruction of the planetary arrangement in space paved the way for the complete replacement of the medieval world-view.
The Revolutions is a curiosity in being written by a devout Catholic wholly committed to the Church which provided his livelihood, whilst one of two prefaces was penned, but not signed, by a member of Luther's inner council, one Andreas Osiander the noted Hebrew scholar. As the Revolutions contained the basis for overturning the established Church's world-view it might be supposed that the Reformers would have acclaimed it immediately. But Philip Melancthon (1497-1560) in 1545 led the rejection in print and their condemnation was swifter than that of the Catholic Church which was prepared to accept the idea of heliocentricity as a hypothesis until the first trial of Galilei in 1616 when the Revolutions was placed on the Index Liborum Prohibitorum. It was reinstated in 1620 when minor ‘corrections’ were made to the text to reinforce the hypothetical aspect of the work and to avoid the claim that it was in harmony with the Scriptures.
A second oddity is that although the Revolutions signifies a turning point in scientific thought it was some sixty or so years before its delayed impact resounded in the scientific world and in the realm of theology. At which time Giordano Bruno (1548-1600), and particularly Johannes Kepler (1571-1630) and Galileo Galilei (1564-1642) provided much of the groundwork for Newton to work on to produce his universal world-view in 1687. The Italian astronomer Bruno was burnt at the stake in Rome in 1600 for promoting Copernicus's views; Galilei was placed under house-arrest in 1633 in Siena and later outside Florence for similar offences against the by-then crumbling world-view of the established Church; whilst the Protestant Kepler safely produced his work in northern Europe.
Both of these peculiar features of the Revolutions will be discussed in the second essay, sufficient to say here that Copernicus was a devout Catholic with a senior position in the Church administration for most of his life, working in northern Europe not far from Wittenberg, and with persona contacts in the reforming movement. This geographical and cultural location provides the context within which explanations may be found as to the source of the apparent anomalies. Before discussing what could be meant by the term in the time of the Reformation, what can be said to comprise a ‘world-view’? For the purpose of this essay it will be taken to denote the human perception of the world as it exists within the universe in space and time and embracing cosmology. ‘World-picture ’is descriptive whilst ‘world-view ’is interpretive. The ‘human perception of the world’ also includes notions as to the meaning of life, the whys and wherefores, and cannot be isolated from theological considerations in western European culture. If it is believed that ‘man is made in the image of God’, it is but a short step to find that there must therefore exist a sequence of correspondences linking man with God[2]. In this intellectual territory are to be found the justifications of astrology, the micro-macrocosmic analogy, the chain of being, and other related notions. This is not the place to delve into these aspects in any depth but they should be borne in mind as forming a significant part of the mindscape within which science and theology existed in Reformation times, for there were interactions.
The central features for a world-view during the Reformation for most people were those inherited from the thirteenth century and centred around certain points which were mainly: the literalness or otherwise of the Creation as described in Genesis[3]; the Earth as the centre of the universe; the size of the Earth and whether it turned on its axis; what, if anything, was beyond the furthest stars and how far away they were[4]; whether God created more than one universe; what kept the heavenly bodies in place. These ‘scientific’ questions (and many others) were interwoven with theological considerations including: the whereabouts of God in the universe; where our souls resided before birth and after death; where heaven could be if the universe was ‘full’; how miracles could occur if the universe was perfectly ordered — and surely it was for God made it; where God was before the Creation; and so on. Such theological questions were endless and provided bed and board for many a Scholastic. A lasting and continuing effect of Copernicus's insight was to dramatically increase the rate of clarification of what could be counted as observable facts and logical conclusions, and what remained in the domain of belief and faith.
For the common person there was little choice in their world-view as they were in receipt of beliefs and opinions passed on by the practitioners and teachers of the conventional faith who in turn had chosen a traditional form for their philosophy of life. For those who questioned the received wisdom must be said that this was done entirely within the theological framework and although the tradition may now be termed ‘radical’ as individuals they were not so — at least in their public utterances, though the tension can be sensed underneath in, say, the Opus Alaius of Roger Bacon (c. 1214-1292).
The term choice is important in the study of things at a distance from earth because ‘sufficient proof’ was impossible to provide in Copernicus time, whereas inference and conjecture were readily elicited from unaided observations. Similarly for the world at large and including small thin below the threshold of human sight, for it was held that only the effects God's work are perceptible, in a mirror as it were, and not His actual workings. Copernicus could only ‘choose’ his interpretation of the universe for it was impossible to prove with adequate rigour what was scientifically true without the use of the telescope for astronomical observations. Not only was Copernicus concerned to accurately describe and to succinctly explain, but he was also motivated by the notion that God acts in the simplest way possible (that is to our comprehension). He had a neat turn for the paradox contained in producing simple explanations from the complexity so obvious in the world about us:
Just as it [Nature] especially avoids producing anything superfluous or useless, so it frequently prefers to endow a single thing with many effects[5].
In these few words can be seen the rationality of the ‘razor’ conceived by William of Ockham (c.1285-c.1349) which was later to form the cornerstone of Newtonian and Positivist philosophy. With the imprimatur of Copernicus this fundamental and medieval concept was launched into the modern world. In choosing, or adopting, this reductive approach to scientific investigation Copernicus illustrates what has come to be called the ‘conditional nature of scientific knowledge’ and that such knowledge is circumscribed by human sense reception and understanding. This issue was taken up vigorously and influentially by Immanuel Kant (1724-1804) who likened his own conclusions in philosophy to a Copernican revolution.
To try to describe the world-view at any one time in history is at best simplistic for there can always be distinguished at least three main strands. It has proved too tempting for many authors to describe — with the doubtful benefit of hindsight — that view which most closely approaches or foreshadows future developments. Few modern authors achieve the balance of theological and scientific understanding which shows that these two were bound up one with another like a double helix, and were even indistinguishable at times.
At the time of the Reformation the three main strands may be summarised: firstly, the biblical accounts and later Christian and Jewish enrichments appropriate (it was thought) for the common people without much formal education; secondly, including the approved Aristotelian science of the Church among the clerics and masters of arts at the few universities and these were under the ultimate authority of the Church; and finally, the third being the critical or radical tradition, also within the ambit of the Church.
At the simplest level the world-view was seen in the statuary and stained glass windows of the great medieval cathedrals which may be described as ‘God's picture book’[6]. In sermons and other discussions something of orthodox science would have percolated into the common domain, but it is unlikely that seriously critical aspects would have moved further downline than to only very few of the clerics and academics. Not until Copernicus was the primacy of faith over reason (logical or empirical) seriously brought into question.
The received world-view for the entire sixteenth century throughout western Europe was the traditional and theologically approved version found in the popular encyclopedias such as Caxton's Myrrour of the World published in 1481[7] to be distinguished from treatises specifically on ‘the globe’ and on astronomy not so much because they are written in a simplified form but rather because they tend to gloss over the difficulties which engaged the leading thinkers both theological and scientific. Interlocked with ‘factual ’accounts of the known world should be mentioned Dante's Divina Commedia (c.1310), but further reference is not appropriate here.
The standard work elucidating Aristotle's world-view was De Sphera by John Sacro Bosco (c.1190--c.1236. otherwise Holywood or of Halifax), in four short chapters (books) which formed the basis for many, probably the majority, of later compilations. Aristotle's world-view was derived from the Greek theoretical, idealist, tradition of Pythagoras and Plato and had the earth at the centre of the universe surrounded by 55 concentric celestial spheres for the planets and stars together with the means of transferring complex (inexplicable) motions. At some time during the very early medieval period these spheres were reduced to eight (sometimes 9 or 10) with additions such as the Empyrean sphere for whatever was thought to lie beyond the universe. The sequence of the planets most usually found medieval treatises is: Earth, Moon, Mercury, Venus, Sun, Mars, Jupiter Saturn, and the fixed stars[8]. The planets were conceived as being fastened on, or in, the spheres and moved by the love of God — ‘love makes the world go round’[9]. Everything beyond the moon was ‘perfect’ whereas in the sub-lunary sphere all was chaos — this accorded with the common experience. The spheres were generally thought of as crystalline (because they can seen through) and solid[10]. Book IV of Sacro Bosco's De Sphera simply peters out when the point came to detail Ptolemy's universe. Ptolemy's Almagest was too difficult for students in the liberal arts courses and the was filled by an anonymous author probably around 1260-80 and probably in Paris. Several hundred manuscripts of Sacro Bosco's De Sphera and the anonymous Theorica Platenorum exist from the thirteenth to sixteenth centuries and they are often bound together. Thus, in medieval treatises are found Aristotle's conceptual model and Ptolemy's mathematical model of the universe.
But this system (or, rather, collection of dubiously related details) ran into two provinces of difficulty early in the thirteenth century. The first having to do with lack of congruence of Aristotle's world-view with biblical accounts and the second with Ptolemaic/Arabic observational astronomy [11]
From at least as early as 1210 Aristotle's world-view in the words of his commentators, and especially Averroës (ibn Rushd), was under heavy fire in the bishopric of Paris because of deductions, inferences, or conclusions which were at variance with Church teaching. Whilst Aristotle could be forgiven because he predated Christ, the subsequent commentators were not only in error if they did not follow the Bible, but also the most notable were Islamic or Jewish and were odious theologically. These shortcomings in Aristotle and/or the commentators fell into certain groups among which were, that: the world was eternal — which effectively denied God's creative act; an accident or property could not exist apart from material substance — which clashed with the doctrine of the Eucharist (transubstantiation, such a crucial element in Reformation England); the processes of nature were regular — which eliminated miracles; and, the soul did not survive the body — which denied the fundamental Christian belief in the immortality of the soul.
During the thirteenth century there were several attempts to ban aspects of Aristotle's work[12] leading to the Summa contra Gentiles (1259-64) and Summa Theologica (1266-74) of Thomas Aquinas (1225-74) and the Parisian Condemnation of 219 Propositions in 1277. These works, with others over the prior period of about 60 years, attempted to ‘cleanse’ Aristotle (384-322 B.C.) from his later commentators bringing his science into some degree of concordance with theological acceptability, though with deep-rooted problems which were certain to resurface.
The general thrust of Aristotle's natural philosophy survived in Church doctrinal thinking largely because there was so much else of his which was acceptable and simply could not be jettisoned. So, after about 1277 the Church having been forced to accept Aristotelian natural philosophy together with Ptolemaic astronomy (and including many of the conflicting aspects) into its theological framework, it became highly resistant to any suggested change to what had been achieved by so much compromise. Denial of any of the 219 Propositions resulted in prompt excommunication so the Condemnation of 1277 was effective immediately and long-lastingly — not least in the subsequent failure to sufficiently acknowledge and give credit to Arabic scholarship as reclaimers, translators, and commentators of ancient Greek texts. Debts of the thirteenth century revival, of humanist studies and the so called Renaissance of the quattrocento to first millennium Islamic scholarship have even now not been adequately acknowledged.
The second set of problems concerned observational astronomy and the supporting mathematics associated with Ptolemy. Without going into too much detail here, the nature of the problems arose from the orbits of the planets not being circular, the planets travelling at different speeds (each planet's year is different), and that the Earth spins on its own axis at an angle to the plane of the orbits. Venus and Mars were always seen in close conjunction with the sun and were assumed therefore to lie between the Sun and the Earth, but they did not appear to pass in front of the Sun. Because of the elliptical paths and varying speeds of the planets at different points on the orbit (faster nearer the Sun) the planets often showed ‘retrogade motion’ (appearing to go back-wards due to the relative positions and speeds of the planets) which was quite inexplicable with a simple geocentric universe.
In attempting to reconcile these and other anomalies astronomers had sought from earliest times to ‘save the phenomena’ by inventing endless combinations of individual motions for the planets resulting in incoherent complexity. The root of the problems lay in the belief that the Earth was at the centre of the universe and in ‘thinking the unthinkable’ Copernicus's insight and intellectual courage played the pivotal role in re-forming the medieval world-view in the direction of the modern conceptual model.
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How scholars within the Church — such as William of Ockham, Jean Buridan (c. 1300-c. 1358) and Nicole Oresme (c. 1320-1382) — sought a route through the trip-wired minefield of scientific research and theological conformity will constitute the introduction to the work of Nicholas Copernicus in Part 2, The Celestial Ballet.
© Bruce Marsden
Emile Mâle, L'Art Religieux du Xllle Siècle (Paris, 1902). Throughout.
First written in Latin in France in about 1245, translated into French in 1464.
But there were variations on this sequence by earlier Greek astronomers, mainly Heraclides (c.390-c.310 B.C.) and Aristarchus (c.310-c.230 B.C.). As these foreshadow Copernicus's heliocentric system they will be discussed in the subsequent essay.