Despite the alternative history of magic and the occult sciences which, once one looks into it, seems to absorb all the energy and endeavour of the sixteenth century, most histories of science take the year 1543 – right in the middle of that century – as their starting date for what is known, with perfect aptness, as ‘the scientific revolution’. In that year appeared Nicolaus Copernicus’ On the Revolutions of the Heavenly Spheres (De Revolutionibus Orbium Coelestium) and Andreas Vesalius’ On the Structure of the Human Body (De Humani Corporis Fabrica). The first revived a heliocentric theory of the universe, but with better mathematics to support it than had been available to its first proponents in classical antiquity. The second put the study of human anatomy on to a firm observational basis for the first time. Prior to these two seminal works, most theorising about the natural world was derived from the frequently misleading authority of the ancients, found in Aristotle, Galen, Pliny the Elder’s Natural History (Historia Naturalis), and elsewhere. Among the first serious challenges to the standing of these great past authorities was a little book published half a century before Copernicus’ On the Revolutions of the Heavenly Spheres, in the year 1492 – a date more popularly associated with the transatlantic explorations of Christopher Colombus and the expulsion of the Jews from Spain. The little volume was called On the Errors of Pliny and Other Medical Writers (De Plinii et Aliorum Medicorum Erroribus) and it was written by one Nicolai Leonicini of Ferrara. It details the mistakes in Pliny’s Natural History, which had hitherto been regarded as both encyclopaedic and authoritative. Leonicini’s original aim had been to establish a correct text of Pliny’s book, into which many textual errors had crept over the centuries as a result of the mistakes, weariness, inattention or other lapses of successive generations of copyists. He entered into correspondence with Angelo Poliziano to discuss the matter, and the correspondence served as the basis of his book. In the process of writing it he had to deal with the question whether the errors were scribal or the fault of Pliny himself. He concluded that what Pliny wrote ‘was insufficiently researched and confirmed by him’.1 That was both a comment on the fallibility of the ancient authorities and a statement of scientific principle, and both constituted a major step towards modern science and the modern world.
Ensuring ‘sufficient research and confirmation’ came into its own as a principle in the century after Copernicus. This was the distinctive departure that made the scientific revolution. Employment of an empirical methodology and quantitative mathematical techniques allowed the later Renaissance’s enquirers to challenge the hegemony over thought not just of the ancient writers but – more importantly still – of religious orthodoxy; and as we have seen to disentangle science from the pseudo-sciences that aimed by quicker and easier means to achieve most of the same ends.
To accept the conventional dating of the beginning of modern science is not to withhold credit from the advances in science, mathematics and technology in the period from classical antiquity until the mid-sixteenth century, for there had most certainly been much of all three, mostly in India, the Middle East and (especially) China. Discoveries in these times and places were relevant to the rise of science in the sixteenth and seventeenth centuries. So too was the development of instruments, chief among them the telescope and magnifying lens, as already noted.
But the nature of progress in European scientific thinking from the mid-sixteenth century is of a different order from what had gone before, and fully deserves the name of ‘revolution’. One has only to look around at the world today, the manifest product of that revolution, to see how true this is. The crucial point is how it was done. Science is the work of many hands – to the names in the seventeenth century of Gassendi, Galileo, Huygens, Boyle, Newton and more, we would continue by adding the later names of Priestley, Volta, Faraday, Maxwell, Einstein, Bohr, Heisenberg, Dirac and still others who are rarely mentioned in popular histories of science. Together they represent the collegial, mutually critical, peer-reviewing, competitive and collaborative community which built a new understanding of the world. This collaborative enterprise took its full shape in the seventeenth century.
To appreciate just how revolutionary the scientific revolution was, it is instructive to compare the world-views prevailing before it began and after it was properly under way. The fullest comparison would be between the world-view of a reasonably well-educated contemporary of Luther’s in the early sixteenth century and that of a reasonably well-educated person today. But in fact the comparison can be made more tightly: between someone living when Henri IV of France came to the throne at the end of the sixteenth century, and someone living when Queen Anne sat on the throne of England at the beginning of the eighteenth century.
When Henri IV became King of France in 1589, what almost all Christian theologians, and certainly those of the Roman Catholic Church, regarded as an acceptable view of the universe – because it was conformable to scripture and sanctioned by the doctors of the faith – was a combination of Christian theology and Aristotelian philosophy. The principal author of this synthesis, magisterially achieved, was St Thomas Aquinas, in the system which has ever since been known as ‘Thomism’. Aquinas brought together the material and the spiritual by joining Aristotle’s science, Ptolemy’s astronomy and Galen’s medical theories – together offering a picture of the material aspect of man’s existence – with the Church’s teachings on the nature and destiny of the soul. He worked the thought of the ancients into a unified philosophy fit to be the servant of theology, not merely thereby constructing a system satisfactory for the faith, but protecting the faith from any apparent conflict with the more ancient (and philosophically much richer and deeper) traditions that preceded it.
This brilliant synthesis, highly elaborate and detailed, constituted the framework for thinking about the world for all denominations of Christian thinkers in the sixteenth century, not just the Catholics; and it provided ground-rules for what could count from a theological point of view as acceptable in philosophical (which meant also scientific) enquiry. It did this despite the fact that it had earlier left plenty of room for debate and dispute among the philosophers of the medieval schools. But in general design the theologically consistent outline of this world-view was what all protectors of orthodoxies regarded as acceptable.
In the sixteenth century as in all the centuries of the Christian era beforehand, revelation was the primary source for understanding God’s purposes and the nature of the universe itself. The Roman Catholic Church had since its beginning taken it as a matter of doctrine that revelation is a continuing process; the Church had licence from the deity to exert its own authority as a source of teachings regarding all matters. It was exactly this view that the proponents of the Reformation rejected in matters of theology and morality.
But both the Roman and Reformation theologians were silently agreed on a different and very significant point: that revelation is to have the final say in all questions of science. For Protestants revelation resides in scripture; for the Roman Catholic Church it lies both in scripture and in the continuous relationship of the Church with God. Scripture by itself was regarded by both as sufficient on such matters as the nature of the universe and its origins; it unequivocally stated that God had created the heavens and the earth, and had populated them with vast numbers of creatures (‘created beings’), including a host of angels, one-third of whom – if we follow the traditions adapted by Milton in his epic of the loss of Paradise – had rebelled and followed the archangel Lucifer, otherwise known as Satan, into hell, from whence they ceaselessly endeavour to upset God’s plan for humankind.
A key point about the religious view of the universe is that the most important consideration in it is the moral purpose for which, in its opinion, the universe exists. That is why the doctrines of the faith subordinated the little said about the origin and nature of the material world to its incidental role as theatre for the supposed grand narrative of the moral story. This story is familiar enough, but bears restatement, because in its incidents and details lie religious, anti-scientific bias.
God’s first human creatures were Adam and Eve, to whom he gave a beautiful garden as a home. Satan seduced them away from their obedience to God, with the result that the entire human race now suffers punishment for their fall. That was the first sin; ‘sin’ means ‘disobedience’; the disobedience in question lay in eating the forbidden fruit of the tree of knowledge of good and evil. That the first crime was disobedience to an injunction not to seek knowledge in a central area of human concern is a speaking fact, and one that connects directly to the disobedience of humankind represented by the scientific revolution itself.
The rebel angels, now in the character of demons, traverse the world in search of souls to capture for eternal damnation, by tempting them into such wickedness as heresy, greed and lust – and false beliefs. In his efforts to rescue mankind from itself God tried various remedies – drowning in a flood all but a handful of human beings so that he could start the enterprise over; sending teachers and prophets, too many of whom were ignored, or driven away, or even killed. Finally – so (most) Christian doctrine has it – God resorted to assuming human form and sacrificing himself as an atonement between himself and humankind. How people respond to that sacrifice will be assessed on Judgment Day, an event confidently regarded as imminent by almost every generation of true believers in Christian history.
These views of course included a plethora of fine details and nuances – details that sent many to the stake who could not agree with (or sometimes perhaps did not understand) them. Doctrine on these matters only began to take established form several centuries after the legendary death of Jesus, and involved much conflict over ‘heresy’ – a word chiefly denoting the beliefs held by the losing side in the argument. But the theories of the natural world adopted by the Church were far older than its theological doctrines, and were still fundamentally Aristotelian in the sixteenth century.
In this Aristotelian theory the physical world consists of combinations of the four ‘elements’ – earth, air, fire and water. There is a fifth element, the ‘quintessence’, called aether, of which the heavenly spheres and their passenger bodies are made. The four non-aetherial elements can manifest any two of the four respectively associated properties dry, cold, hot and wet. Their combinations give rise to the characteristic nature of physical entities: earth is cold and dry, water is cold and wet; fire is hot and dry, air is hot and wet. Each of the four elements has its natural place. Earth, because it is heavy, tends towards the centre of the universe. Water is also heavy, but not quite as heavy as earth, so it lies on the earth’s surface. Air occupies what would otherwise be the empty gap between water and fire, which latter is the lightest element. Fire is most at home above the earth; some later thinkers said it is what can be seen twinkling at night through the many little apertures in the spheres that surround the earth.
According to this theory we never encounter the elements in their pure and original form. They only ever come as alloys or mixtures. This is readily shown by experiments in chemistry, in which the elements are separated or rendered pure, chiefly by heating them. This is what gave rise to alchemy; if everything is a combination of the four elements, and if these mixtures can be separated out and then recombined in different ways, it must follow that precious metals such as gold can be formed from a base metal such as lead, and it must be possible to find the substance that would guarantee long life, perpetual youth or even immortality in the flesh. For example: gold is the most beautiful and desirable metal and – obviously – the most useful to own. This means that it must be a perfectly proportioned mixture of the four elements. Baser metals, consisting of unequal proportions of the elements, therefore need only to be reassembled into perfect proportions to become gold. It was further concluded that because gold is the perfect arrangement of the elements, it must likewise be the best possible medicine. This belief led to its being swallowed in liquid form as a cure for a wide variety of ailments.
Aristotle inferred from the ‘nature’ of each of the elements what their ‘natural motion’ is: earth and water have a naturally downward motion, while air and fire have a naturally upward motion. But this motion would occur only if something else applies a force to them, just as a person moves a pebble by throwing it. If the impulsive force ceased, so would the motion it produces. Accordingly there is no concept of inertia in Aristotle’s science. This was a major reason why a God was needed, to get things moving in the first place – the spheres of the stars and planets, for example – and then either to keep them moving or to arrange for agencies to do the work for him.
The theories of astronomy developed in antiquity were also adopted, more or less unchanged, by Christian thinkers. The heavenly bodies were thought of as orbiting a stationary earth occupying the centre of the universe; they were carried along in ‘crystalline spheres’ that had been set going by God and which were kept moving in their orbits – so some authorities taught – by a superior kind of angels (called ‘Intelligences’) whose duty it was to keep the stars and planets in their allotted courses. The spheres were made of crystal because they had to be both transparent and solid, and the only then known natural material combining these two properties was crystal. The beauty of crystal was a further recommendation for this important office.
The moon is the lowest and nearest of the sky’s residents, and the least refined; its sphere has the swiftest revolution around the earth. Then, in order of distance from the earth, come Mercury, Venus, the Sun, Mars, Jupiter and Saturn, each of them revolving more slowly than the one beneath it. They are composed not of earth, air, fire and water but of the fifth element – the ‘quintessence’ – and their orbits round the earth are perfect circles. They are themselves similarly perfect, and like Plato’s Forms they are unchanging. As they circle round the earth they pour out divine music – rather as a string hums when a weight is attached to one end and is swung round – which we humans cannot hear because of the baseness of our material bodies. The faithful who make it to heaven will be able to hear the music of the spheres on arrival.
The theory has yet further elaborations, from the medico-psychological theory of ‘humours’ – which we still refer to in talking of someone as melancholy or bilious, sanguine or phlegmatic – to astrological theories of personality and fate, and from there to the idea that the human world is a divinely ordered hierarchy from the highest king to the lowest serf. Indeed the theory of ‘degree’ extends even further than the human social hierarchy, for it runs from God all the way down to the humble worm. Human beings are situated halfway between, the link between angels and beasts, sharing a bit of the nature of each – and therefore acting as the link between earth and heaven. This theory also had its subtleties; angels know more than humans do, but humans are better than angels at learning; humans have more intelligence than beasts, but beasts have more strength than humans; and so forth.2
Most of this constituted the world-view of the educated and (perhaps in more rudimentary form) of the uneducated for many centuries, right through the sixteenth century and into the seventeenth. It is difficult now to imagine what it was like to think in these terms. In many respects it was a satisfying and even comfortable view – despite the devil and his agents constantly prowling about to ensnare one into eternal torment: a ghastly thought – for it put humankind and its world at the centre of creation and made it God’s chief interest and care; and it made man (here I use the masculine term advisedly) the lord of that world at least in temporal terms. To be confronted with a profoundly, even violently, different view of the universe; to be confronted with the highly unsettling idea that the earth is not stationary at the centre of things, but flies through immense tracts of empty space in a universe larger than imagination can grasp; that the universe is not actually about humankind or for humankind – this is not merely a blow to humanity’s self-esteem (no longer to be a possible hero in a cosmic and eternal drama is quite a demotion), but it is in itself vertiginous at least and positively terrifying at worst.
Worse still, these new theories directly challenged, indeed impugned, scripture in particular and the authority of religion in general. The proposal that we should view the earth as flying round the sun through great arcs of space seemed to the Church to be worse than a lie – it was a blasphemy; remember Cardinal Bellarmino’s warning to the Carmelite monk Foscarini: Psalm 104 verse 5 unequivocally states that God ‘set the earth on its foundations; it can never be moved’. Bellarmino had further warningly reminded Foscarini that God made the sun stand still as a help to Joshua in massacring his enemies – was this not conclusive proof that it is the sun, not the earth, that moves through the sky? No wonder that the Church was prepared to put to death those who refused to accept the scriptures as the repository of scientific truth.
The stage was thus set for conflict between, on the one hand, a new world-view based on commitment to observation and reason unconfined by the requirement to square with religious doctrine, and, on the other hand, the authority of scripture and the Church. It was a direct confrontation. The Counter-Reformation’s new shocktroops, the Jesuit order founded in 1534, which had astutely chosen education as its prime weapon in the war to recover Christendom’s lost souls for Rome, described its curriculum in its Ratio Studiorum (schedule of study) in the following unequivocal terms: ‘In logic, natural philosophy, ethics and metaphysics, Aristotle’s doctrine is to be followed.’ This instruction was issued by Francis Borgia – generally known as St Francis Borgia, General of the Jesuit order, in a memorandum which went on to state that no one is allowed to ‘defend or teach anything opposed, detracting, or unfavourable to the faith, either in philosophy or theology. Let no one defend anything against the axioms received by the philosophers, such as: there are only four causes, there are only four elements, there are only three principles of natural things, fire is hot and dry, air is humid and hot. Let no one defend such propositions as that natural agents act at a distance without a medium, contrary to the most common opinion of the philosophers and theologians . . . This is not just an admonition, but a teaching that we impose.’3
‘This is a teaching that we impose.’ It is not surprising therefore that the new ideas advanced by science were greeted with vigorous opposition and sometimes persecution. And this was despite the fact that the first advocates of the new ways of thinking did not venture them as alternatives to Church doctrine. In the preface to his classic work, Copernicus said only that a heliocentric hypothesis made better sense of observation and the associated mathematics, but it must be regarded as an heuristic device merely, not a claim that he wished his readers to take literally.4
There is therefore a stark contrast between the pre-scientific world-view which constituted orthodoxy at the beginning of the seventeenth century and the world-view that science has developed since then. The real contrast, of course, is between the kinds of thinking that respectively give rise to these ways of looking at the world. As Bertrand Russell said, it is not what one believes but one’s reasons for believing it that really matter; and what the seventeenth century put to work to its full and proper extent was a different way of acquiring beliefs about the natural realm. The repudiation of the obedience of faith in matters of enquiry was the clinching point; the contrast in the outlooks is most economically described as follows.
Religion in the ideal offers us the supposed word of a deity or deities. Its chief requirement is that we believe in the benevolent government of the deity or deities and respond accordingly – which means, to worship and obey, not to doubt and question, but to accept: that is the meaning of ‘faith’. In two of the world’s leading religions, Christianity and Islam, this is a cardinal virtue. ‘Islam’ indeed means ‘submission’; in Christianity likewise submission to the authority of the deity is central – the prayer that all sects utter, the ‘Our Father’, includes the words ‘not my will but yours be done’ – and a trope of observance is ‘dying to oneself’ and ‘handing oneself over to God’. One of the worst sins is ‘pride’, which means relying on one’s own judgment and standing on one’s own feet, in this way repudiating the doctrine that the frailty of mankind in every respect requires the support and salvation of the deity. Faith as acceptance even in the face of reason and contrary evidence is a great virtue, as witness the story of Doubting Thomas in the Gospel according to John (chapter 20 verses 24–9), and the teaching of Søren Kierkegaard about ‘the leap of faith’ (more accurately, the ‘leap to faith’) needed to cross what Gotthold Lessing had described as the ‘ugly wide ditch’ that he could not leap over in order to believe in a religion based on claims about miracles. In this Lessing was a true child of the Enlightenment, one of whose leading figures he was. Had he known the witticism of his near-contemporary David Hume that the age of miracles was not over because the fact that people still held religious beliefs was a miracle in itself, he would doubtless have appreciated it.
Science is a markedly different matter. In the ideal it is an objective and impersonal endeavour that seeks to be as intellectually responsible as possible in devising and testing hypotheses, and in going where the evidence leads. It does not have a conclusion in advance, for which it seeks support; that is the way of the dogmatist. On the contrary, it does everything it can to exclude bias, and to conduct itself in openly scrutable ways, with its results being subject to public challenge, independent verification, and replication of results. Reliance on observation, rigorous reasoning, careful design of experiments and constant review by independent scrutineers are the standard commitments of scientific procedure, and together are the least that is expected of anyone seriously engaged in scientific enquiry.
If evidence were required for the success of science’s methods and norms, one need only say, si monumentum requiris, circumspice: look around at today’s world. The results of scientific endeavour are overwhelmingly endorsed by outcome. The application of science by means of technology is testimony to its success and – arguably – its advance towards truths about the world; even if, as must always be acknowledged, the benefits are not unmixed with problems that science and technology also bring.5
The relevance of this to the intellectual revolution under consideration is of course a straightforward one: the seventeenth century is the moment when one world-view was displaced by another because the scientific version displaced that of faith. ‘Displacement’ is the appropriate word. The universe revealed by science is toto caelo different from the various universes portrayed by religions. These latter offer us a small human-centred creation having an expressly moral purpose – that of serving as a testing-ground for human beings, preparatory to their real existence after bodily death in either a paradisical or hellish eternal reality. Here human powers of imagination impose the limits on what nature can be, whereas in science far more can be envisioned, though only through the lens of mathematics – a conceptual tool of much greater range and accuracy than human fantasy – and experiment. Scanning the horizon of modern science’s progress from Galileo and Newton to relativity and quantum theory, and adding to these their accompanying advances in chemistry, biology and technology, we see that science reveals the impoverishment of pre-scientific views of the universe, and the limits of human imagination.
One distinctive characteristic of the scientific mind-set is scepticism, accompanied by readiness to adjust one’s opinions when better evidence or more persuasive argument indicates that they are inaccurate, and to change them when they are shown to be wrong. For this reason science requires freedom both of expression and of enquiry; it cannot conform to a non-scientific agenda, no matter whether theological or political. If the effect of theological dogma on sixteenth-century science is not persuasive enough an example of this, consider ‘Soviet biology’ and in China the agricultural miracles of rice production in which yields were made to seem hugely increased – achieved, of course, by deceptively filling paddies with rice harvested from elsewhere, so that when top Party cadres drove by they could witness the miracle of agricultural fertility that Marxist-Leninist-Mao Zedong science made possible.
The Soviet and Maoist climate of pseudo-thought is closely analogous to what existed in the sixteenth century and beforehand, when the Church demanded, on threat of punishment, that scientific enquiry should not disagree with doctrinal orthodoxy. All too familiarly, the Church was prepared to persecute to guarantee observance of this requirement. The example always rightly cited is that of Galileo.6
The example of Galileo’s trial matters because it marks the last major attempt by the Church to prevent or at least control the scientific revolution. Like the story of modern science itself, the story once again begins with the publication in 1543 of Copernicus’ classic De Revolutionibus. The aim of that work, one recalls, in offering a heliocentric model of the universe, was to provide an easier way to characterise the movements of the stars and planets than had been provided by the geocentric model of Ptolemy. That model – formulated in the second century CE on the accumulated data of (literally) millennia of star-gazing – began from the assumption that the stars, sun, moon and the five planets then known all orbit the earth in perfect circles, the reason being that of all geometric figures the circle is most perfect.
But observations of stellar and especially planetary movements did not fit this assumption; too many anomalies and irregularities were observable. We now know that because the planets in our solar system follow elliptical orbits around the sun at different speeds and distances from it, some of them between earth and the sun and some far outside earth’s circumsolar path, they will appear to an earth-bound observer sometimes to speed up and sometimes to slow down, and even to go back on themselves at times. They wander across the majestically wheeling backdrop of the ‘fixed stars’ with apparently purposeful whimsy. To cope with their perceived variabilities, adjustments to the perfectly circling system had to be made.
Ptolemy therefore proposed that, although the planets indeed move in perfect circles, they do not do so around the earth itself but instead around points which themselves travel in perfect circles around the earth. These local orbits within their larger earth-orbit are called ‘epicycles’. The points themselves each sit in the plane of a crystal sphere, and these crystal spheres also move in perfect circles, but again not around the earth itself but around a set of points called ‘equant’ points which are situated just a little way from earth.
These refinements are obviously ad hoc, indicating that the model is jerry-built; all the adjustments and embellishments are invoked to square antecedent assumptions (‘the heavenly bodies must of course move in perfect circles’) with recalcitrant observations. They are like the extra Maoist rice in the paddy field. A much older idea, put forward by Aristarchus in the third century BCE (500 years before Ptolemy), that the sun sits at the centre of the universe with the earth and other bodies orbiting it, seemed simpler to Copernicus, and when he tried it he found that it fitted the observational data more accurately and effectively.
Copernicus was Polish (not German as Fontenelle had it), born in Toruń on the Vistula river. His father, who was a wealthy man, sent him to study in Italy where, in the early years of the sixteenth century, he absorbed humanist culture, learned Greek as well as Latin, and made translations of texts from one to the other. He had gone to Italy to study medicine and law, but appointment to a sinecure as a canon of Frombork Cathedral at home in Poland allowed him to dedicate his life to study instead.7
His interest in astronomy was sparked during his time in Italy, when he read a summary of Ptolemy’s system published together with observations and questions by the German savant Regiomontanus (Johannes Müller; his scholarly name is a Latinised obeisance to the city of his birth, Königsberg). In his commentary Regiomontanus discussed a long-recognised problem with Ptolemy’s geocentric model, which is that it does not accord with what we see of the moon, whose apparent size does not fluctuate as the Ptolemaic model says it should. That model would have the moon regularly seeming to get larger and smaller as it first approached and then withdrew from earth – which it would do if it were moving in a perfect circle round its equant point. Copernicus solved the problem by hypothesising that whereas the moon indeed orbits the earth, it and the other planets, together with the crystal sphere of the stars, all together orbit the sun. This gives the happy result that the universe has a single centre, this being the sun, rather than a rash of equants near the earth.
But it introduces problems of its own. If the earth is flying round the sun, why do we not feel the wind of its movement blowing in our faces? Why do the oceans not rise and flood over the land just as the water in a bucket spills over the edges when the bucket is swung round? If the sun is at the centre of everything, how is it that the earth and planets do not fall into it? If the crystal sphere of stars orbits the sun too, it must be extremely far away from the planets, leaving a yawning gap between themselves and the solar system. Why would God create such an oddly shaped universe?
There was too little knowledge in the sixteenth century to provide answers to these puzzles. But other aspects of Copernicus’ model made it compelling. One is that it allowed Copernicus to answer a different awkward question, which is: Why can Venus and Mercury only be seen at dawn and dusk whereas Mars, Jupiter and Saturn are visible at any time? Ptolemy’s answer had been that Venus and Mercury accompany the sun on its voyage round the earth, but Copernicus saw that the difference must imply that Mercury and Venus have orbits inside earth’s orbit, placing them closer to the sun, while the other three have orbits outside the earth’s orbit. Accordingly he was able to place the planets in their right order by inferring it from the pattern of their heliocentric orbits relative to the earth: outwards from the sun the order is Mercury, Venus, earth, Mars, Jupiter, Saturn. This simple result is beautiful science.
Although Copernicus arrived at these ideas as a young man he did not publish them, recognising their dangerous implications, until the very end of his life. Indeed it is said that a finished copy of his book reached him from the publisher as he lay on his deathbed. It is a touching but probably untrue tale. He was persuaded, against his inclinations, to publish by his friend Rheticus (Georg von Lauchen), the Professor of Mathematics at Wittenberg University. Rheticus had published an outline account of Copernicus’ system years before, in 1540. A Lutheran minister named Andreas Osiander was hired to prepare Copernicus’ full manuscript for the press, a task for which he became solely responsible when Copernicus fell into his last illness. The book appeared a quarter of a century after the Reformation began, and just a year after the Roman Catholic Church launched its eventually anti-science Counter-Reformation at the Council of Trent.
Osiander was the author of the much quoted preface stating that Copernicus’ system is not to be taken as describing the true layout of the universe, but instead should be regarded merely as a model or hypothesis. He did not put his own name to the preface, so allowing it to be believed that Copernicus himself had written it. Osiander’s motive is easy to understand: he knew that if the theory were claimed to be true it would invite condemnation. But despite the disclaimers he inserted in the preface, his fears were soon confirmed as justified.
An historical oddity attaching to this story is that when Copernicus first developed his ideas, more than thirty years earlier in 1510, he made a synopsis of them and circulated them to acquaintances in a manuscript entitled Commentariolus (A Little Commentary). The pamphlet excited admiration, even in the Vatican, where it was the topic of a talk given in the presence of Pope Clement VII by a papal secretary named Johann Widmanstadt. A cardinal present at the talk, Nicholas von Schönberg, wrote to Copernicus urging him to publish a more complete version of the theory. When Copernicus’ book appeared in 1543 the cardinal’s letter was printed at the beginning, a figleaf which proved inadequate to protect those who were later persecuted – even burned to death at the stake – for accepting the Copernican view.
The year in which Copernicus published the early sketch of his theory, 1510, lay in the lull between the end of the excesses of Torquemada’s Spanish Inquisition and the nailing of Luther’s Theses to the church door at Wittenberg. It was the era of Erasmus’ influence, whose fame, and the irenic nature of whose humanism, had a positive although only temporarily calming effect on the European mind. It was not a time when zealous attention was paid to recondite works of natural philosophy in the hope of detecting heresy.
Just thirty years later matters were very different. Copernicus’ hesitation about publishing is a speaking fact. So is Osiander’s attempt to disguise the heliocentric theory as merely a mathematical heuristic. Osiander knew his Bible; he knew Psalm 104, he knew that in chapter 10 of the Book of Joshua it says that the sun stood still for an entire day, and the moon likewise. Copernicus and God were therefore authors of competing accounts, so unless Copernicus could be represented as saying that he did not seek to challenge the veracity of scripture, there would be trouble.
But of course there was trouble anyway. It was inevitable that the implications of Copernicus’ model would attract the Church’s notice. It is perhaps surprising that it did not happen earlier, but the second half of the sixteenth century was a time of much distraction and anguish arising especially from the wars of religion. It took a particular incident to obtrude the implications of Copernicus into the Church’s awareness, and until then his views were ignored or overlooked. That incident was the trial for heresy of Giordano Bruno, and his execution in Rome in February 1600.
Bruno was not a discreet man. Like many of his contemporaries in the late sixteenth century he had a wide-ranging and miscellaneous set of interests in Hermeticism, mysticism and much besides, but he also openly stated his acceptance of the Copernican model as a correct description of the universe. He did this in full consciousness of the danger; but he did it anyway. When it became apparent during the two decades after Bruno’s execution that increasingly many savants were persuaded by the literal truth of the heliocentric theory, Copernicus’ De Revolutionibus was put on the Vatican’s Index of Forbidden Books where – along with most of the rest of the world’s greatest and most influential literature, which the Index has inadvertently raised to prominence – it shed its undimmed mathematical radiance on the scientific revolution that followed.
The event that precipitated this typically heroic act by the Church was the attempt by Foscarini, already described, to persuade the Church that scripture and Copernicus were not at odds. Bellarmino’s response on behalf of the Vatican could have been written at any time in the preceding thousand years, but it could not have been written a mere fifty years later. It would be hard to believe that Bellarmino and his colleagues in the hierarchy of the Church were not conscious that the current of history was against them, were it not that the Church remained so obdurately wedded to its beliefs for centuries afterwards despite no longer being able to compel others to believe likewise. Although the Church was unwilling to tolerate theories that disagreed with scripture, it was even then increasingly reaching a position where it had little choice in the matter. Its silencing of Galileo on this point, by threatening him with death, was in effect its last throw of that die.
Galileo had been a problem for the Church for more than two decades when it finally indicted him before the Inquisition on the Copernican question. Trouble had begun early, in 1604, when he lectured on Kepler’s supernova observations, demonstrating that it had to be as far away as the rest of the fixed stars, and that therefore it had to be one of the fixed stars undergoing change – which contradicted Aristotle’s (and therefore the Church’s) view that the stars never change. Galileo’s lecture also therefore had troubling implications about the size of the universe.
Then Galileo constructed his own telescope and made astonishing discoveries by its means. He had heard that someone in the Netherlands had made a powerful ‘spyglass’, so, using his considerable gifts as both a craftsman and a mathematician, and putting what he knew of the laws of refraction to work, he made one for himself. This was in 1609. His first telescopes had a magnification of approximately four, but he was soon grinding lenses that yielded a magnification of eight or nine. He had entrepreneurial as well as scientific talents, and turned this work into cash by persuading the Venetian Senate that he was the inventor of the telescope and that it had great potential in military, commercial and maritime respects. The Senate gave him a generous sum for the right to manufacture his ‘perspicullum’. He had to quit Venice very hastily when the Venetians learned that he was not the telescope’s inventor, and had no rights to the patent they had bought from him.8
Although Galileo was alive to the commercial value of his version of the telescope, he was more acutely alive to its scientific promise. Through it in December 1609 he saw something that put the seal on humanity’s changing conception of the universe. He saw mountains on the moon, sunspots, a vastly more numerous array of individual stars in the Milky Way, and several moons orbiting Jupiter. He immediately gave the name ‘the Medicean stars’ to these moons and sent news of their discovery and their names – along with a good telescope – to the Medici ruler of Florence, the Grand Duke of Tuscany, Cosimo II. As a reward the Duke appointed Galileo ‘Ducal Mathematician and Philosopher’ at a large salary.
Galileo published his telescopic discoveries in his Sidereus Nuncius (The Starry Messenger). This short book made him famous everywhere in Europe. Yet his most fascinating discoveries were yet to come. He continued to gaze through his telescope, making more accurate observations of Jupiter’s moons. While pondering certain inconsistencies in the data he thus collected, he realised that he had to take account of variabilities in his own position relative to the motions of the planets and their satellites, variabilities which could be explained only if the earth was itself moving round the sun. This constituted powerful evidence that Copernicus’ model was much more than a mere heuristic, but rather a literally correct description of the solar system.
Galileo had in fact been convinced of this since at least 1598; in that year he had written to Kepler saying that he was a Copernican. But he did not say anything publicly at this juncture, aware of the implications; he continued to enjoy plaudits and honours, including election to a fellowship of the prestigious Accademia dei Lincei in Rome.
But the Copernican theory would not lie quiet. One of Galileo’s former pupils, Benedetto Castelli (1578–1643), a professor of mathematics at Pisa University, was invited by Cosimo II and his mother the Grand Duchess Christina of Lorraine to give a lecture on the contradictions between the Copernican model and scripture. In his lecture Castelli defended the Copernican model, and afterwards wrote to Galileo to tell him that he had done so. In reply Galileo said what he thought: that scripture should always be interpreted according to the discoveries of science, not, as the Church required, the other way round. Somehow copies of his letter got into the hands of the Inquisition. At that point the Inquisitors did nothing, most likely waiting for a better moment to make life difficult for Galileo.
Unwisely, Galileo was made bolder by their inaction, and himself wrote to the Grand Duchess Christina in 1616 saying,
I hold that the Sun is located at the centre of the revolutions of the heavenly orbs and does not change place, and that the Earth rotates on itself and moves around it. I confirm this view not only by refuting Ptolemy’s and Aristotle’s arguments, but also by producing many on the other side, especially some pertaining to physical effects whose causes perhaps cannot be determined in any other way, and other astronomical discoveries; these discoveries clearly confute the Ptolemaic system, and they agree admirably with the Copernican position and confirm it.9
This letter in its turn also fell into hostile hands, and now the Church felt compelled to act. Pope Paul V ordered Cardinal Bellarmino to refer the question of Galileo to the Sacred Congregation of the Index (the Inquisition’s official label). Its cardinals considered the matter in February 1616. They took evidence only from theologians; neither Galileo nor any other scientist was invited to testify, nor was he or any other scientist asked to submit written evidence. Unsurprisingly the cardinals concluded that the Copernican theory must be condemned, pronouncing the heliocentric view not merely ‘foolish and absurd’ but heretical, adding that the idea that the earth flies through space is ‘at very least erroneous in faith’.10
‘Erroneous in faith’: this phrase, offered in rebuttal of scientific observation, might have an alien ring now, no longer carrying the threatening weight of authority as it did then; but alas there are too many still for whom it retains significance. That this can still be so in the twenty-first century illustrates a problem to be solved. But in the seventeenth century it was the scientific view, not the concept of the trumping truth of doctrine, that seemed to the Church to be the problem.
Cardinal Bellarmino accordingly summoned Galileo to an interview, reported what the Sacred Congregation had concluded, and told him that he was therefore and thenceforth forbidden to hold, defend or teach the Copernican theory. Some historians suggest that neither Bellarmino nor Pope Paul V wished to see Galileo in trouble. They even (some go on to add) wished him to be free to continue teaching the Copernican theory, and for this reason their version of the ruling did not contain a prohibition against teaching it. But when Bellarmino informed Galileo of the Sacred Congregation’s ruling, he did so in the presence of its members, who were eager for an opportunity to prosecute Galileo further. They had inserted the prohibition against teaching in order to see whether he would agree. Because they were present, therefore, Galileo had to agree, and Bellarmino’s attempt to spare him the prohibition was foiled. This embellished story goes on to claim that Galileo was immediately afterwards invited to an audience with Paul V who assured him that while he, Paul, was on St Peter’s throne, Galileo would be safe.
This pleasant story does not, alas, have much truth to it. If Bellarmino and Paul V were Galileo’s allies, and by extension therefore friends to the Copernican theory, Foscarini would not have been admonished, and Galileo would not have kept so loudly silent for the remainder of Paul V’s life. He would almost certainly not have waited to publish his next important work, Il Saggiatore (The Assayer), a disquisition on scientific method, until a new pope – a positively Galileo-friendly pope – was in the Vatican.
This was Pope Urban VIII, installed on St Peter’s throne in 1623. Before then he was Cardinal Maffeo Barberini, and had been a friend to Galileo’s work for a long time. Galileo now published his Assayer and dedicated it to Urban. It contained a passage that became and remains famous:
Philosophy is written in this grand book, the universe, which stands continually open to our gaze. But the book cannot be understood unless one first learns to comprehend the language and read the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures without which it is humanly impossible to understand a single word of it; without these one is wandering in a dark labyrinth.
Pope Urban laughed uproariously at Galileo’s digs at the Jesuits in The Assayer when it was read to him. He invited Galileo to a total of six audiences, showing him favour and friendship, and thereby leading Galileo to believe that he could resume teaching the Copernican theory openly, not least in the magnum opus he was then busy writing, his Dialogo sopra i due massimi sistemi del mondo (Dialogue Concerning the Two Chief World Systems). His work on the book was slow because interrupted by bouts of recurring ill health, which delayed its completion until 1629. When it was finished he sought permission for its publication by the Accademia dei Lincei in Rome; but because it happened just then that the Academy was in turmoil following the death of the ‘Chief Lynx’ – its president – and even though he had the censor’s approval, Galileo decided to publish in Florence, where after yet further delays – this time caused by outbreaks of the plague – it at last appeared in 1632.11
There was no trouble at first, but Galileo’s enemies were waiting for their chance, and they soon spotted it. Galileo’s principal enemy was a Jesuit named Christoph Scheiner – rather aptly because he had written about sunspots (aptly but, according to Galileo, ineptly – thus attracting Galileo’s scorn, which had filled Scheiner with resentment. They each accused the other of plagiarism, and otherwise crossed swords; history has been unkind to Scheiner, who after all was quite an expert on the sun, and invented the pantograph). Scheiner and his allies found their chance in the fact that Galileo had printed the censor’s preface to his book in a typeface different from the main text, thus distancing himself from it, and moreover had given the dialogue’s defeated disputant a remark to the effect that the Copernican system was merely an hypothesis. This cautionary observation had been recommended to Galileo by Urban VIII himself, as a way of protecting the book. Galileo’s opponents persuaded Urban that attribution of the words to the unsuccessful because less intelligent contender in the debate was an insult to Urban, who was accordingly angered.
The Jesuits now had their chance. They scoured Galileo’s writings in search of further damning evidence, and there it was in the 1616 judgment forbidding Galileo to hold, defend or teach the Copernican system, which he was manifestly doing – doing all three – by giving the exposition and defence of it to the Dialogue’s winning party.
Galileo was again required to appear before the Inquisition. He delayed as long as possible, pleading illness. His former protector at Florence, Cosimo II, had died some time before, and the new young Grand Duke did not know how to play at politics with the Vatican. Galileo eventually had to give in and go to Rome.
He arrived in February 1633, and was immediately put on trial. The outcome was never in doubt; Galileo was sixty-nine years old – a grand age in those days – arthritic, almost blind, ill and weak. He recanted. He was obliged to say, ‘I abjure, curse and detest my errors,’ and to deny that the earth moved. He thereby saved himself from execution. Instead he was condemned to life imprisonment, and, as mentioned earlier, the sentence was commuted to house arrest at his home in Arcetri. He spent the closing decade of his life there, fruitfully engaged in writing his last book, the Discorsi e dimostrazioni matematiche, intorno a due nuove scienze (Discourses and Mathematical Demonstrations Concerning Two New Sciences), which described and summed up his life’s work. It included accounts of the pendulum, inertia and mechanics, and expanded his views on scientific method. He was visited in his retreat at Arcetri by many men of distinction, including Milton and Hobbes.12
Galileo undoubtedly knew that although he had lost a battle, science had won the war. His Dialogue and especially his Two New Sciences were immensely influential among learned men everywhere in Europe, and fuelled the scientific advances that followed. Italy, in contrast to the rest of Europe, was scientifically paralysed by the Inquisition’s condemnation of Galileo, and became a backwater.
The history of seventeenth-century science moves seamlessly from Galileo to Harvey, Huygens, Boyle and the great achievement of Newton, taking the formation of the Royal Society in 1662 on the way. Theories that failed are left out of account because they are not signposts on the high road to the present. But it is of significance to note that there was for a time a competitor as a new physics: the system devised by Descartes.
In the second half of the seventeenth century and afterwards Descartes’ scientific theories were much debated. What attracted attention was not his philosophical views as studied in universities today, but his physics, and specifically his theory of ‘vortices’. Newton challenged Descartes’ theory at the close of Book II of the Principia in preparation for setting out his own account of how the motion of bodies occurs ‘in free space without vortices’.13
Descartes’ theory was that the universe is a plenum – a solid continuum – of matter in different states. There is no vacuum; space and matter are the same thing. For objects to move they have to be moved by something other than themselves. Descartes argued that this entails that there must be indefinitely many local vortices or swirls of matter in different grades of coarseness or fluidity, the matter at the outer margins of each vortex moving more swiftly than the matter at the centre. Because of the nature of the matter at the centre of vortices, where it forms as fluid around bodies, the centres of vortices are suns, and their outward pressure on the universal fluid is what we experience as light when our eyes are turned towards them. The heavenly bodies are made of coarser particles of matter, and are transported by the vortices – the earth itself does not move, being without its own principle of motion, but it is carried round the sun by the fluid vortex encompassing and supporting it.
Descartes explained motion in the vortices according to his theory of mechanics, which uses only the concepts of size, speed and rest or motion. These latter two states of bodies depend upon the mechanical interactions between bodies, imparting motion or change. Vortices contain three types of matter: aether, consisting of very fine fast-moving particles of the kind that constitutes the sun and stars; tiny, smooth spherical particles which Descartes called ‘celestial matter’; and lastly larger irregular particles that aggregate or stick together to form planets and comets.
Although Descartes’ theory looks like an ingenious way of being Copernican without being theologically unorthodox – in his theory the earth indeed orbits the sun, but does not itself move, for it is carried passively along in its vortex – its main basis lay in adherence to the principle that there is no vacuum. The subsequent history of science shows that Descartes was wrong about this, but his mistake had two fruitful consequences. The first relates to his theory of vision, which is that vision is the result of pressure on the eyeball by the universal fluid. The sun, for example, is the centre of a vortex, and its outward pressure on the universal fluid translates into pressure on any eye directed towards it. (Newton offered a refutation of this by saying that if vision is caused by pressure in this way, anyone could see in the dark by running fast enough. Descartes has an answer: no one can run fast enough to see in the dark.)14 Descartes’ idea is an antecedent of thinking of light as waves emanating from a source, rather like the ripples caused by a stone thrown into a pool. This idea was explored later in the seventeenth century by Christiaan Huygens; Descartes was on to something right.
Secondly, the theory of vortices had a great negative utility in being what Newton rejected in the search for his own theory of gravitation. Newton’s theory involves accepting ‘action at a distance’, in contrast to the seemingly more sensible theory of Descartes that there can be no such thing. The resulting controversy between the Cartesians and Newtonians was fierce. The Cartesians adhered to the common-sense idea that physical interactions must be the result either of collisions between particles describable in terms of mechanics, or (as in Descartes’ theory) of the fact that everything is physically connected to everything else in the plenum, so that pressure and motion is transmitted by contiguity. The competing idea that there can be action at a distance without such contiguity led to the concept of the field, eventually of great importance in Maxwell’s work on electromagnetism in the nineteenth century, and in the whole subsequent development of physics. But at the time Newton’s claim that gravity acts instantaneously at any distance without a mediating physical link seemed like an invocation of ‘occult powers’, a notion that the Cartesians vigorously opposed.
Newton’s rejection of the Cartesian vortex theory was, however, well founded. For one example, he showed that Descartes’ view conflicts with Kepler’s third law – the ‘Harmonic Law’ which relates two quantities, one being the time it takes for a planet to orbit the sun, the other being the planet’s mean distance from the sun. In direct contrast to what is entailed by Descartes’ theory, Kepler’s third law states that the planets closest to the sun move at the greatest speeds and have the shortest orbital periods. According to Descartes it should be the planets furthest from the sun that move fastest. Further, Newton showed also that unless there is a constant input of energy at the centre of each vortex, vortices could not sustain themselves in being; Descartes had failed to consider this problem.
Descartes’ foremost achievement was, arguably, to help solve a quite different problem, one that was every bit as important if not more so. It was the familiar and pressing problem of the relation between science and religion. As the case of Galileo demonstrated to anyone who thought about it, there was a serious need to separate, or find a way of separating, the spheres of religion and science, given the apparent impossibility of making them compatible, or otherwise achieving peaceful cohabitation between them. The alternative to finding a solution to this problem was the suffocation of scientific enquiry, as so vigorously attempted by the Church to that point. This was a separate problem, but it was every bit as urgent, from the methodological problem of separating science from the magia, alchymia, cabala entanglement that continually threatened to misdirect it.
An idea that attracted those eager for a solution was to argue that religion and science are not competitors for the truth in the same regions of enquiry. If religion could attend exclusively to matters of heaven and spirit, while science restricts itself to the sublunary world, there would be no need for the Church to be anxious about the hypotheses and discoveries of science, and science would be able to proceed without incurring the sometimes mortal danger of upsetting religious sensibility.
The challenge of arguing for a separation of the spheres of science and religion was accepted by the same two major figures who had argued for the disentanglement of science and occult philosophy: René Descartes and Francis Bacon. Precisely because Descartes had made significant contributions to mathematics and science, it mattered to him personally that his scientific work should not be seen to impugn the Church’s teachings. This was based on his anxious desire to please the Jesuits, in particular, who he hoped would adopt his books as texts for their schools, for they were still teaching Aristotelianism and Thomism, which he emphatically opposed. Although Descartes had been a pupil of the Jesuits at La Flèche, and perhaps their servant in the espionage of the Thirty Years War, he was disappointed in this hope; his books were soon to find their way on to the Vatican’s Index of Forbidden Books – like that of Copernicus, and just as much of an unintended honour.
The solution to the problem of the competing spheres of religion and science lay in a theory Descartes advanced in his Meditations on First Philosophy. In it he argued that mind and matter are essentially different substances – using these terms in their technical philosophical senses: essential denotes ‘of the essence or defining nature’ and substance denotes what is metaphysically basic and fundamental. He put the contrast by defining mind as thinking stuff, res cogitans, and matter as spatial stuff, res extensans. This division between mind and matter caused his philosophical successors serious problems, most especially with the question of how the two substances can interact. As Princess Elisabeth asked, how can mental events cause bodily events – how does the thought ‘It is time to get up’ result in my body rising from the bed? – and how do bodily occurrences result in events in consciousness such as feelings of pain and pleasure, emotions and memories?
Despite these problems, the theory nevertheless offers a solution to the problem of whether Church doctrine is threatened by treating the physical world exclusively in terms of scientific law. That solution is to treat the material realm as a mechanism which God had invented and set going, thereafter running in accordance with the laws – the laws of science – that he had laid down. The seventeenth century’s dominant scientific analogy was clockwork, as described by Fontenelle in his Conversations on the Plurality of Worlds. Matter was visualised as composed of atoms or ‘corpuscles’ (‘little bodies’) interacting on mechanical principles. Descartes’ separation of the realms was intended to serve as a licence not merely for the scientifically minded to get on with their investigations of the mechanism of nature, but for the devout to let them do it without anxiety. Scientific enquiries, he implied, would not touch the great spiritual truths; instead they are a celebration of the handiwork of the divine.
An even more robust line on the question of science’s relation to religion was taken by Francis Bacon. He wished to specify techniques of enquiry that would yield truth and practicality, as described in an earlier chapter, but it is easy to overlook the significance of his achievement in this regard. He effectively unseated the antecedently prevailing view that was premised on two things: the belief that the ancients (not just the philosophers of classical times but the Cabalists, Hermeticists and magicians too) knew more than the moderns, and the alleged certainties of revelation and Church authority. Earlier enquirers and the Church were thus taken as the two fountains of truth, telling us how things are. As we saw, Bacon opposed this view by arguing that, through observation and experiment, enquiry should begin again on a different foundation with the aim of discovering how things are in themselves. He also argued that the outcomes of scientific enquiry should be used to advance the practical interests of humankind. We now take it for granted that scientific research, technological invention and advances in the techniques of both have practical applications as their major aim; but we also take it for granted that pure research, the pursuit of knowledge for its own sake, can often turn out to have highly useful applications. When Bacon pointed this out it was by no means the commonplace it has since become. In his day knowledge, if the quest for it were permissible, was either conducted for its own sake entirely, or it was regarded as providing support for the orthodoxies of faith.
Practical people – the farmers, blacksmiths, shipbuilders, carpenters, masons and others mentioned earlier – had of course always observed and learned from the world, as a result inventing technologies and improving the ones they already possessed. Bacon wished to re-establish the connection between theory and practice; that is one underlying tenet of empiricism outside the ivory tower. And the point is that the practical endeavours of blacksmiths and carpenters had never been in conflict with dogma; indeed carpentry had a most respectable lineage in this regard.
Another significance of Bacon’s contribution is that it helped to change thinking not just about the nature of knowledge but about the possibility of its acquisition. It was as if his immediate predecessors among thinkers lacked confidence in their capacity to make original advances in knowledge. Bacon changed this. He represented an aspect of the Renaissance mind which did not think it was confined only to rediscovering and copying, but was capable of discovering and making new advances.
Once again, the fundamental point was that all this is possible only if scientific enquiry can proceed in freedom. That meant drawing a clear line between the business of religion and the business of science. Bacon’s emphatic view that it is always a mistake to ‘commix together’ science and religion played a major part in liberating enquiry from the demand for doctrinal conformity.
The argument between science and religion in the seventeenth century was an argument about authority – authority over minds and outlooks. At the beginning of the century the Church was prepared to kill in order to keep control of what can be thought; by the century’s end this was no longer possible in Europe. Alas, it remains possible in a number of regions in today’s world – a state of affairs which shows that those parts of the world still await their seventeenth century and its offspring, the following century’s Enlightenment.
But the change of view about what is to have intellectual authority is central to the emergence of the modern mind itself, as witness how the idea that observation and reason are those authorities – rather than the Church’s teachings or the supposed wisdom of the past – came to be an assumption of the Enlightenment. Note this: an assumption, not a hope or a claim, but something taken for granted, so far had minds been freed from the trammels of dogma. The scientific attitude – the attitude of rational enquiry controlled by the facts and dedicated to understanding the universe and relating it to practicalities – had come to displace the previous intellectual authorities as what must supervise thought and action.
This change is the key to understanding the Enlightenment of the following century, which at its core is shaped by the idea that the methods and concepts of science should be applied in all domains of enquiry, as far as is consistent with the subject matter in question. Newton was enough of a scientist, despite his occult interests and hopes, to close his Optics (published in 1704) with the words, ‘if natural philosophy in all its parts, by pursuing this Method [i.e. scientific method], shall at length be perfected, the bounds of moral philosophy will be also enlarged’. By ‘moral philosophy’ he meant, as his contemporaries meant likewise, all of ethics, politics, economics, psychology and history. This is what makes the Enlightenment what it was: an extension of the scientific approach to wider domains of interest. It is the idea that underlies the Encyclopédie of Diderot and d’Alembert. Its consequences include among them the major political revolutions of the eighteenth century. Writing in the mid-eighteenth century David Hume noted that there had been ‘a sudden and sensible change in the opinions of men within these last fifty years, by the progress of learning and liberty’.15 At the time he wrote those words they were more true of England than most other parts of Europe, and of the British colonies in North America; but they were true enough everywhere to be an important part of the explanation for the great revolutions that transformed politics and society in those colonies and France, and eventually large parts of the world.
A point on which Bacon repeatedly insisted was that science should be a collegial affair, and that there should be institutions dedicated to co-operative scientific research. He decried the habit of the supposed cognoscenti who kept as close to their chests as possible whatever secrets they learned about nature. From the 1590s he broached the idea of an academy of science; when James I came to the throne he argued that the ancient universities should be encouraged to set up science research institutes, and when it became clear that this was unlikely to happen he resumed the case for a self-standing such institute. This is one of the chief reasons why he is cited by the founders of the Royal Society of London as an inspiration.
Attempts had been made to establish scientific societies as early as the sixteenth century, in imitation of the ancient academies of Plato and Aristotle, which had been closed after nearly a thousand years of existence by the Christian Emperor Justinian in 529 CE. Justinian’s reasons were these:
We wish to extend the law that we and our father, of blessed memory, formerly made against all still-remaining heresies – we call ‘heresies’ those beliefs which hold and assert anything other than the teaching of the catholic and apostolic orthodox church – in order that the law should also apply to Samaritans and pagans, so that, because they do so much harm, they should no longer have influence, or respect, or serve as teachers of any subject, in case they drag the minds of simple people into their own errors, and in this way take the more ignorant among them away from the pure true orthodox faith. Thus we permit only holders of the orthodox faith to teach and to be paid from public funds.16
The principal sixteenth-century effort to establish a specifically scientific academy – there were already literary and humanistic ones – fared no better. Founded by the polymath Giambattista della Porta in Naples under the name Academia Secretorum Naturae – the Academy of the Secrets of Nature – its membership was open to anyone who could present ‘a new fact in natural science’.17 The Inquisition investigated it in 1578, and as a result Pope Gregory XIII ordered its closure on suspicion of sorcery. The suspicion was doubtless deepened by the mere title of della Porta’s book, Magia Naturalis (Natural Magic).
The next effort was the founding of the Accademia dei Lincei – the Academy of the Lynxes – by Federico Cesi, son of the Duke of Acquasparta. Cesi was a devotee of botany, but with his fellow founders he wished to extend enquiry into all forms of science. They named their academy after the picture on the front cover of della Porta’s Magia Naturalis, which was of a lynx, together with a legend adverting to the lynx’s legendarily sharp eyesight which enabled it to observe everything in the minutest detail – even through walls and stone – just as a scientist should.
The Lincean Academy effectively died when Cesi did, in 1630 (though while it was still engaged in publishing a monumental multi-volumed account of the flora, fauna and pharmacopoeia of Mexico it kept going, until 1651. The Academy was revived in the nineteenth century and now occupies the handsome Palazzo Corsini in Rome). But while it lasted it promoted the ideal of observation – Cesi’s motto was minima cura si maxima vis, ‘care of the little things yields maximum results’ – and Galileo was proud to become a member of it.
Some of Galileo’s students were among those who founded the Accademia del Cimento in Florence in 1657. Unlike other scientific societies the Cimento never organised itself on a formal basis, but remained a group of friends who, under the patronage of two sons of Cosimo II de’ Medici, pursued their investigations independently and jointly. Nevertheless they had a significant impact on scientific procedure, stating adherence to the experimental method, making instruments for laboratory use, standardising systems of measurement, and insisting (as their motto had it) on Provando e Riprovando – ‘try and try again’ (or ‘prove and again prove’). The group published a manual in which they described experiments, the highly accurate instruments they had made for the purpose of those experiments, and the carefully calibrated systems of measurements they had devised in order to record weights, times, temperatures and pressures. The book – Saggi di naturali esperienze fatte nell’Accademia del Cimento – took more than five years to write and is handsomely illustrated with drawings of instruments along with instructions for their use.18 Members of the Cimento corresponded with members of other societies around Europe, but because it never put itself on to an institutional footing it eventually disbanded as the individual members grew old, drifted away or died.
Matters were otherwise with the Academia Naturae Curiosorum, founded in Schweinfurt in 1652, and better known as the ‘Leopoldina’. It still exists as Germany’s national scientific academy, until recently known as the Deutsche Akademie der Naturforscher Leopoldina. It therefore lays claim to be the oldest continuously existing scientific academy in the world, and the first to publish a journal, the Ephemeriden or Miscellanea Curiosa. From the outset the society had a primary interest in medicine and physiology. It was only after the First World War that it acquired a permanent home, until then being located wherever its current president happened to live. (It is now based in Halle.) The blot on its copybook is its expulsion of Jewish members in the Nazi period, among them Einstein. There is no doubt that this is something most of its extraordinarily distinguished roll-call of members would regret: in addition to Einstein it includes Goethe, Darwin, Max Planck, Ernest Rutherford and Otto Hahn.
In France an informal academy of science sprang up around Henri Louis Habert de Montmor, writer and polymath, who was one of the founding members of the Académie Française in 1634. He wished to set up a parallel academy for science, and invited friends to join him. He was a serious scientist; he edited the complete works of Gassendi after the latter’s death, and in imitation of Lucretius wrote a poem called De Rerum Naturae on Cartesian physics. Some of the men who joined his informal Montmor Academy were very distinguished – they included Pierre Daniel Huet, Adrien Auzout, Girard Desargues, Samuel Sorbière, Claude Clerselier (the associate of Descartes), Jacques Rohault, Gilles Roberval and Christiaan Huygens.
The society lasted until 1664, dispersing as a result of quarrels among some of its members, but one of them, Auzout, persuaded Louis XIV – or more accurately, his chief minister Jean-Baptiste Colbert – of the need for a publicly funded observatory and associated academy. In 1666 the Académie des Sciences came into existence as a result. At the outset it had, like the Cimento, no formal constitution and no rules apart from a prohibition on discussing religion and politics. It met informally in the King’s library. In 1699 Louis XIV at last gave it the equivalent of a Royal Charter: a set of rules, the right to call itself the Académie Royale des Sciences, and a home in the Louvre.
In the vicissitudes and changes of France’s always interesting political life, the adjective ‘Royale’ came and went several times, as did the academy itself when the Revolution incorporated it into a new structure of academies. Its membership was not always exclusively scientific; Napoleon was elected to it, and indeed became its president (on the strength of having been to Egypt). Its own worst blot is that it did not admit women to membership until 1979 – which meant that Marie Curie, twice winner of a Nobel Prize, was excluded.
The Royal Society of London is often regarded as paradigmatic of what an academy of science should be. It grew out of the so-called Invisible College of the 1640s in England, the period of the Civil War, and came into more formal existence in 1660 when Sir Christopher Wren, then Professor of Astronomy at Gresham College in London, together with a group of friends, decided to set up ‘a Colledge for the Promoting of Physico-Mathematicall Experimentall Learning’. Besides Wren the early members included Robert Boyle, John Wilkins and Sir Robert Moray. The members employed Robert Hooke as their first Curator of Experiments, and met weekly to witness experiments and discuss ideas.
Sir Robert Moray told King Charles II about the society, and the King took an interest. In 1662 he granted it a Royal Charter incorporating it as ‘The President, Council, and Fellows of the Royal Society of London for Improving Natural Knowledge’. The Society adopted the motto Nullius in Verba which in effect means ‘don’t take anyone’s word for it’ – that is: look and think for yourself, go to the facts, test and examine. Among its first publications was Hooke’s Micrographia.
The idea of a ‘Colledge’ specifically for the pursuit of scientific enquiry was not derived from the idea of an Oxford or Cambridge college – though the members of the Invisible College of the 1640s had largely been based in Oxford – but instead came from Bacon’s idea for ‘Solomon’s House’ in his New Atlantis, published in 1627. A character in the book says, ‘Ye shall understand (my dear friends) that amongst the excellent acts of that king, one above all hath the pre-eminence. It was the erection and institution of an Order or Society, which we call Salomon’s House; the noblest foundation (as we think) that ever was upon the earth; and the lanthorn of this kingdom. It is dedicated to the study of the works and creatures of God.’ Among the duties of the ‘Fellowes, or Brethren’ of this institution is that of venturing abroad to learn everything about the knowledge and productions of other societies: ‘there should be a mission of three of the Fellowes or Brethren of Salomon’s House; whose errand was only to give us knowledge of the affairs and state of those countries to which they were designed, and especially of the sciences, arts, manufactures, and inventions of all the world; and withal to bring unto us books, instruments, and patterns in every kind’.
Developments in military technology and in scientific discovery were often closely connected. Studies of the movement of planets and the movement of cannon balls were related, the telescope brought moons and opposing armies equally into focus, new engineering principles were applied in fortification building. The access of power and technique brought by these advances is well illustrated by the difference between the Ottoman sieges of Vienna in 1529 and 1683 respectively. In the first, the Turks were only just beaten back, and they remained in possession of a large slice of central Europe and the Balkans after it. Centuries later residents of these regions would still refer to a journey across the old frontier as ‘going to Europe’.19 The Ottoman invasion of 1683 was a very different affair. One hundred and fifty thousand Ottoman troops were met by a Polish–German force of 68,000, and were comprehensively defeated by them. The clinching Battle of Zenta fourteen years later saw over 20,000 Ottoman troops killed for the loss of 300 in the Imperial Austro-Hungarian army, with all the Turkish artillery and supplies lost (along with ten members of Sultan Mustafa II’s harem). The Battle of Zenta was a significant moment: it ended the ambition of the Ottoman Empire to increase its possessions in Europe. The date of the battle is resonant: 11 September 1697. Moreover it was on 11 September that the siege of Vienna was lifted in 1683, at the beginning of the final war waged by the Turks to conquer Europe. Those who find significance in such things – and there are plenty who over-emphasise coincidences – naturally take it that those who flew the fateful aircraft into New York’s Twin Towers and Washington’s Pentagon on 11 September 2001 chose that date for this reason, as presaging the return to power of their view of the world.
The superiority of weapons that at last drove off the Ottoman threat is part of a larger story about the relation of science and war in the seventeenth century. It is told in the next chapter.