7. Earth and Heavens Observed

NATURE AND DIVERSITY

The age of discovery was not merely the exploration and settlement of a new continent, the encounter with the world’s oceans, and the locating of Europe within them. It was also the unearthing of a new sense of nature and the universe. Christendom’s theologians believed that the natural order was subservient to God and that the created universe was a reflection of his divine will. God could use nature to stimulate us to magnify his greatness and be in awe of his creation and omnipotence. The continuing volcanic action on Mount Etna and the legendary salamander’s regeneration through fire were taken by St Augustine as examples of God’s intervention in nature to remind us that God could make human bodies burn for eternity. The biblical record was ample evidence that he could cause extraordinary events to occur in the natural world. Meteorites, comets, monstrous births and other strange phenomena should be taken as warning signs of God’s wrath or of imminent great events. At the least, they were an acknowledgement that nature was unpredictable, shifting and irregular.

In the Central Middle Ages Christendom recovered the teachings of Greek philosophers – particularly Aristotle and Galen – which coalesced with what was already known as the Ptolemaic geocentric universe. Nature became an ordered and comprehended space, part of the universal and divinely sanctioned truth alongside theology, things that we could know for certain and which constituted ‘knowledge’ (scientia). Because divine and human truth were the same thing, natural philosophy was an integral part of Christendom’s structures of belief. Given the complexity of the natural world (and the human body as a part of it), Aristotelian natural philosophy and Galenic medicine concentrated on general statements about the causes of certain phenomena. To have done otherwise would have risked compromising the certainty of knowledge, finding endless variants for which there was no explanation, and entering a world of dangerous uncertainty. So medieval philosophers created an Aristotle in their own image. They marginalized some works (the treatises on physics, meteorology, zoology, biology and natural history) in favour of others (the metaphysics). In a similar way, Galenic medicine (recovered through Latin translations of Islamic medical texts) offered explanations of human physiology and disease rather than the practica of therapeutic cures. Aristotelian forms, elements and the primal qualities of hot, wet, cold and dry (the basis of Galenic humoral pathology) made nature conform to ‘science’.

The demands of certainty, however, meant accepting that nature was not governed by inexorable ‘laws’. There needed to be room for the variants that occurred in the natural world. Nature obeyed ‘rules’ (regula) not laws. She was a divinely instituted ‘Artificer’, whose habits and inclinations explained the movement, gestation, generation and decay that occurred in the natural world. The Aristotelian-Galenic explanatory framework was reassuring. The large-scale picture (the macrocosm) mapped onto the smaller-scale one (the microcosm), a framework matching the local with the universal. In its homeostatic and organic universe nothing challenged God’s infinity and power. Its truth was confirmed by what could be observed by everyone and by what had been experienced in the past.

Human beings saw the heavens spinning in apparently circular motion above their heads, defining time. They equally expected things to be different on earth. There, some heavy things fell to the ground whereas others did not. Solid bodies acted differently from liquids and air. Aristotelian philosophy explained this difference between terrestrial and celestial behaviour. The spheres were composed of a single element (aether) whose natural motion was circular, and which might be denser or rarer, but never substantially changed. The heavens were, like God himself, eternal and changeless. The comets which appeared from time to time were ephemera, meteorological phenomena in the upper atmosphere. Earth, by contrast, was composed of different elements (earth, air, fire, water) whose essential behaviour, motion and transformation defined their differences one from another. The complexity of terrestrial matter was considerable but not infinite. It was encased by the celestial aether and its transformation and motion were limited. Everything was, relative to everything else, local. Heavy bodies might fall, but their velocity was defined, and they would eventually find the place of rest which the universe dictated for them. Solids might liquefy and liquids might vaporize, but their new condition was one that their ‘form’ defined and constrained. There could be no such thing as emptiness, since space itself was defined by that which gave form to a body – length, breadth and depth. Scholastic writers even attributed to nature a horror vacui, a force by which nature resisted allowing a vacuum to form.

The kind of nature that came to the forefront in the course of the sixteenth and early seventeenth centuries was different. It was a cornucopia, so diverse that it could not conceptually, methodologically or institutionally be embodied in a science in the way that Aristotelians understood that term. Sixteenth-century naturalists concentrated on the discovery of the particular. That was partly what humanist philology and palaeography had been about. The Greek ‘historia’ meant ‘learning by enquiry’, and natural history was part of the rhetoric of ‘discovery’. The best-known ancient natural history was Pliny the Elder’s. Pliny’s contemporary, the Greek physician in the service of the Roman army Dioscorides, also furnished an encyclopaedia of plants, animals and minerals with their medicinal uses. Both works attracted the attention of humanist editors. A similar focus on particularity occurred in the medical world. Physicians had always noted the symptoms which they encountered when diagnosing the ailments of their patients. But, in the newly edited texts of the ancient Greek physician Hippocrates they discovered a clinical doctor who emphasized the symptoms of a disease over diagnosing its causes.

The study of nature’s particulars followed from the texts themselves. In order to establish what the words used by Pliny and Dioscorides for certain plants meant, they had to be related to examples in the real world, which required hunting them out. Similarly, Hippocrates’s works stimulated physicians to write case-notes on their patients’ conditions and to study particular ‘cures’. The latter were often associated with thermal springs such as those at Padua. Each spa had healing properties which were specific to particular ailments. At the same time, there was a growing appreciation of botanical plants for medicinal purposes. Medical faculties sought to control the activities of apothecaries, practitioners whose commercial success attested to the success of applied knowledge of medicinal plants (‘simples’) and the preparation of medicines (‘compounds’). That oversight entailed emulating the apothecaries, and medical faculties began appointing professors of medical botany, such posts being commonplace by the 1550s.

Medicinal cures stimulated the foundation of botanic gardens. The construction of the one for the medical faculty at Padua, opened in 1545, was directed by the Italian architect Daniele Barbaro. Its circular garden was constructed around a rampart. Drawing on military architecture, tunnels provided access to the enclosed parterres. From the rampart, students looked down on the world of nature, laid out in geometrically interlocking shapes. The design incorporated a labyrinth, and it was inspired by Vitruvius, whose works Barbaro had edited. The plan was ingenious, but it implied that medical simples were an enclosed world in which there was no more to be discovered. Later university botanical gardens were more flexible. That constructed at Leiden in 1590 – its first director being Charles de l’Escluse (Carolus Clusius) – had a capacity for over 1,000 plants and fenced-off beds to protect the rarest species. The University of Montpellier’s garden used designs by Pierre Richer de Belleval to create local climates and increase the range of plants that could be grown.

Luca Ghini, professor of medical botany at the University of Pisa, was perhaps the first botanist in Europe to collect plant specimens, press them flat and dry them, and then attach them to card to form the equivalent of a botanical garden in a desiccated form, his ‘herbaria’. The resulting hortus siccus (‘dry garden’) was an encyclopaedia. The herbaria of the 1530s and 1540s described about 800 vascular plants (i.e. with tissues for conducting water). In 1623, the Basel botanist Caspar Bauhin’s catalogue enumerated over 5,000. Instruments for use as well as ornamentation, surviving herbaria from this period are annotated with cross-references and different vernacular identifications. Ulisse Aldrovandi, professor of fossils, plants and animals at Bologna, the moving force behind the creation of its botanical garden and the author of natural histories, described his own collections (which were opened in 1617 as Europe’s first public science museum) as a ‘digest of nature’ (Pandechio di natura). Visitors regarded them as an ‘eighth wonder of the world’.

These collections resulted from the exchange of information and specimens among naturalists by correspondence. Studying nature signalled one’s eligibility to belong to the ‘republic of letters’. The latter was a virtual community whose social composition was fluid (it included apothecaries, physicians, academics, printers, publishers, gentlemen-scholars and aficionados – with aristocratic women only at the margins). Part of the appeal of studying nature in this way was that it was immune to Europe’s political and religious divisions. Its virtuosi were unlikely to be accused of atheism, given that (as they emphasized) they discovered the evidence of God in nature. Naturalists themselves were aware they were engaged in a collective enterprise, conscious that they could not master nature’s diversity on their own. In the preface to his natural history of Spanish rare plants (Rariorum aliquot stirpium per Hispanias observatarum historia, 1576), Clusius at Leiden said that he was overwhelmed by the arrival of new specimens. His contemporary Adriaan van de Spiegel echoed his sentiments: ‘no human mind, however diligent, will ever achieve a wholly perfect knowledge of plants, for their variety is infinite’.

Plant anthologies (florilegia), emancipated from medicinal botany, grew more detailed and richly illustrated. The woodcuts prepared by Hans Weiditz II for Otto Brunfels’s Illustrations of Living Plants (Herbarum vivae eicones, 1532) could be used to identify a specimen. Leonhart Fuchs’s Natural History of Plants (De historia stirpium) of 1542 provided a small-format gazetteer for plants for use on field-trips. Seventeenth-century, large-format florilegia concentrated on particular regions or even specific gardens. Botanical commonplace books became essential for naturalists to manage the increasing volume of information.

In Rome, the aristocrat Federico Cesi spent his fortune on patronizing the new science. In 1603, he founded the Academy of the Lynxes, named after Lyncaeus, the sharp-eyed Argonaut. Its members collected specimens, examined and recorded what they saw and communicated their discoveries to one another in special cryptographic writing. The Lincean Fabio Colonna pioneered the use of etching for plant illustration which, even more than copper engraving, conveyed their morphology and texture. Galileo Galilei was elected an academy member in 1611. He counted on their patronage to protect his astronomical discoveries and sent fellow-Linceans his occhialino (microscope) in 1624. By inverting telescope technology, Galileo furnished a way of discovering that nature was even more varied than one could discern with the naked eye: ‘I have seen,’ he wrote, ‘those little animals in the grains of cheese, in truth a stupendous thing.’ The academicians used the microscope to study bees. The emblem of the Barberini, a powerful Florentine family, was a trigon of bees, and Maffeo Barberini had become Pope Urban VIII in August 1623. The opportunity to demonstrate to the pontiff that the Linceans could ally papal prestige with discoveries of God’s power in nature was not to be lost. The preface addressed to the new pope in the Melissographia (1625) explained that ‘great miracles have emerged . . . and the eye has learned to have greater faith’. In accompanying publications, the Linceans included pleas for tolerating their new approach. The microscope penetrated beyond the superficially visible to discover that, in the underlying structure, nature decomposed into geometrical shapes. The reticulations of the bees’ eyes mirrored the hexagonal cells of the beehive. In the Lincei portfolios, cross-sectional drawings reflect their concentration on these inward structures.

By the early seventeenth century, common-sense classifications of flora and fauna were breaking down. Naturalists’ methods emphasized the importance of morphological descriptions and differences, which accentuated the diversity in nature but did not help with classification. Plant nomenclatures, initially confused by a plethora of vernacular variants, were gradually subsumed into generic classifications. Local knowledge became something more universal. But classification on the basis of what one could superficially observe (colour, texture, size) seemed no longer to work. The more naturalists saw, the less observation on its own offered a secure basis for taxonomy. As Galileo and other natural philosophers insisted, the evidence of the senses was too subjective to reveal the hidden constants in the world of nature.

What was true of botany was also true in zoology, where books on fishes (by the distinguished Montpellier physician Guillaume Rondelet) and birds (by the French ornithologist and traveller Pierre Belon) described and illustrated species on the basis of observations, relating those which they found to those discovered by the ancients and making sense as seemed best of the accretions of mythology and earlier Christian fantasy. As they confronted exotic nature from outside Europe, however, they were compelled to ‘undress’ the objects in nature which they had hitherto dressed up with emblematic meanings. In addition, as the animal kingdom grew larger, it posed a problem for those natural philosophers who sought to imagine what Noah’s Ark had been like. The Bible stories of the Garden of Eden, the Tower of Babel, Solomon’s Temple and the Flood were taken as defining the potential, but also the limitations, of human wisdom and the framing of the created order. The particularities of each story came under scrutiny, raising more questions than could be answered. To accommodate the new species in the Ark defied the laws of physics.

The conventional wisdom was that natural philosophers were ‘recovering’ the wisdom of the ancients. The title-page engraving of the Universal History of Plants (Historia plantarum universalis) of Johannes Bauhin, Caspar’s elder brother, and his fellow-botanist from Basel Johann Heinrich Cherler, published in 1650–51, depicted a garden, surrounded by ancient worthies (Theophrastus, Dioscorides, Pliny, Galen) whose example had inspired the ‘moderns’. In reality, however, the latter were discovering new knowledge, and in new ways. Natural history involved collecting ‘rarities’ from strange places. Finding specimens required travel, and physicians increasingly took their students on botanizing expeditions to out-of-the way places. A few naturalists travelled outside Europe (Francisco Hernández to Mexico, Leonhard Rauwolf to the Near East, Prosper Alpino to Egypt, Garcia da Orta to India), but the majority of animals and plants in the world beyond European space were known only indirectly through travellers’ accounts and specimens. Even so, the result was an accretion of data about species which had no equivalent in the records from Antiquity. They included walrus with curious teeth from Russia, elks that resembled no animal a European had ever seen before, remarkable carnivorous plants from South America, and birds of paradise which reportedly had no feet because they never landed on the earth. The banyan tree (Ficus indica) had branches that grew upwards and downwards at the same time.

The potential for new medical cures seemed infinite. The Spanish physician Nicolás Monardes published a study of medicinal plants encountered in the New World. His book Medical study of the products imported from our West Indian Possessions (1565) included the first account of the therapeutic benefits of what the Spanish named ‘tobacco’. Translated into English and published in 1577, the work was optimistically entitled: Joyfull Newes out of the Newe Founde Worlde. Only in the seventeenth century did naturalists begin to have extensive direct experience of the world beyond Europe and, with it, the capacity to separate out the untruths which their own emblematic world view, coupled with inadequate sources of information and their conception of the world outside Europe as ‘strange’, had perpetuated.

Nature also lay at their doorstep. Conrad Gessner went into the mountains to collect material for his botanical history. He described reaching the summit of Mount Pilatus near Lucerne as finding a new paradise. Gardens became a natural philosophers’ retreat. It was not in the university lecture-room or the pages of Aristotle that truth about nature was to be found, but in gardens, kitchens, the countryside and collectors’ cabinets. The study-space for nature expanded and so did its audience. The growth of urban gardens was an offshoot of the spread of urban space. Gentrified horticulture and arboriculture were a parallel development, the dominion over nature being expressed through the grafting of fruit trees or the cultivation of hybrids. Books about nature appealed beyond botanical aficionados to a wider market where the exotic and the novel in nature generated enthusiasm. In Rome, the Jesuit priest Giovanni Battista Ferrari published the first work devoted to ornamental flowers (De Florum Cultura, 1633). It included several illustrations of the ‘Chinese rose’ (Hibiscus mutabilis), which he cultivated for the first time in a European environment, and which changed colour in the course of a day. In the Netherlands, tulips became a commercial speculation. People were prepared to pay colossal prices for brightly coloured and rare varieties to put into gardens and window-boxes, until the bubble burst in 1637.

Princely courts fed the interest in the exotic. They were repositories for lions, tigers, Turkish hens, dwarfs, fools and automata of all kinds. Rarities, like religious relics, were treasured and became part of the pageantry of secular and ecclesiastical authority, divertissements from the boredom of court life. Aristocratic and courtly collectors were drawn to the power over the natural world which ‘possessing’ it afforded. Giuseppe Gabrieli, giving his inaugural lecture as professor of ‘materia medica’ at the University of Ferrara in 1543, emphasized how the subject was ‘not only for humble and lowly men, but people from every social class conspicuous for political power, wealth, nobility and knowledge such as kings, emperors, princes’. He praised the d’Este princes for their patronage, and said natural history had raised ‘its head from the most profound darkness’ to become the ‘only science of divine origins, given to men by the Gods’.

Rulers vied with one another to secure the services of naturalists. In 1544, Cosimo I de’ Medici, first grand duke of Tuscany, lured Luca Ghini from Bologna to Pisa to manage his botanical garden. The papacy realized the possibilities of presenting itself as head of a global Christianity which embraced the whole of nature. In the 1560s, Michele Mercati was invited to create the papacy’s botanical garden and to supervise a mineralogical museum (the Metallotheca). Mercati’s teacher, Andrea Cesalpino, who had succeeded Luca Ghini to the chair at Pisa, left the Medici to join the papal household after Mercati’s death in 1593, having already acquired a reputation for his precise classification of plants as well as a description of the circulation of the blood which prefigured William Harvey’s discovery. Not to be outdone, Philip II commissioned his physician, Francisco Hernández, to go to Mexico to collect plants, animals and minerals. In 1576, he despatched sixteen large volumes back to Spain, along with thousands of specimens and illustrations, commissioned from native Aztecs. So diverse was the material that it languished in the Escorial library, though part of it found its way to Rome, where it was published by the Linceans. Meanwhile, the Valois promoted the career of their Overseer of the Royal Collection of Curiosities at Fontainebleau, André Thevet. In the following century, Johan Mauritz of Nassau-Siegen established a zoo, botanical garden and museum in ‘New Holland’ (Dutch Brazil). He commissioned Georg Margraf to produce a natural history (published in 1648), copies of which Johan Mauritz used as gifts. Court artists presented the natural world in beguiling ways for their audience. Jacopo Ligozzi in Florence, Teodoro Ghisi at the Mantuan court, and Giuseppe Arcimboldo in the service of the emperors Maximilian II and Rudolf II evoked the natural world as an escape from political and religious divisions while the artists of the School of Fontainebleau created cornucopian visions of nature’s plenty, the richness of nature becoming a metaphor for the largesse of the French monarchy.

Collecting natural objects was a shared occupation and a means to comprehend and thereby exploit nature. Botanical gardens and anatomy theatres acquired ‘cabinets of curiosities’. Physicians, apothecaries and natural philosophers were joined by Counter-Reformed clerics (the Jesuit Athanasius Kircher, founder of the Roman College Museum) and magistrates (Nicolas-Claude Fabri de Peiresc in Aix) as the fascination for collecting broadened and deepened. The largest and most varied cabinets required princely resources. The most celebrated in the later sixteenth century were in the palaces of the Gonzaga in Mantua, the Upper Castle at Ambras, owned by Archduke Ferdinand II of the Tyrol, and those of emperors Maximilian II in Vienna and Rudolf II in Prague. The latter’s were so extensive that, after his death, his successor, Emperor Matthias, persuaded his brothers that the collection should be thereafter inherited by the eldest member of the family and kept in a special Treasury.

MONSTERS, MARVELS AND MAGIC

Within the medieval Aristotelian consensus, it was always possible that nature, while obeying its own ‘rules’, might produce accidental results – children with six fingers, comets in the upper atmosphere, and so on. Such happenings might be like the droughts, plagues of locusts, angelic manifestations and prophetic dreams in the Bible, signs from God to his chosen people. They might equally be the work of the Devil, whose ability to send ‘false prophets’ also had biblical attestation. Violent portents disturbed nature and so the temptation was to assign them to some demonic force. The appearance of ‘monsters’ (conjoined twins, for example) was transgressive, a sign that the Devil was responsible. Then again, it was possible that nature could produce ‘marvels’ which were simply ‘prodigies’, preternatural (against the natural order of things) rather than supernatural (divinely orchestrated miracles). The question was how to read the signs in the natural world.

That issue was a consequence of the emphasis on particularity and strangeness in nature, and it was not resolved before 1650. It was also a concomitant effect of the struggle to absorb new and apparently divergent phenomena from outside Europe. The New World was immense, but also marvellous and monstrous. Monstrosity signalled the breakdown of inherited, common-sense categories into which flora and fauna, as well as natural events, were classified. The emphasis on ‘prodigies’ in nature was another way of expressing the blurring of categories between what was ‘natural’ and what was not. In curiosity cabinets there were often ‘monstrosities’ whose deformities were the object of speculation. The Gonzaga collection in Mantua included a stuffed two-bodied puppy and a preserved human foetus with four eyes and two mouths. The objects at the Schloss Ambras included a painting of a ‘wild man’. The individual in question was from the Canary Islands, and he and his daughters suffered from a genetic ailment, resulting in a superabundance of bodily hair, which rendered them objects of speculation about monstrous barbarism. When the Linceans dissected a hermaphroditic rat or studied a deformed nestling, it was not apparent what distinguished nature’s rarities from its aberrations.

The literature about monsters and prodigies irrupted before the Protestant Reformation, especially in Northern Italy and Germany. In a crescendo of rhetoric about the need for spiritual reformation and knowledge of the Bible, unnatural events were interpreted as God’s anger at human sin. The survival of Christendom seemed to be at stake. Printed accounts of monsters and portents generated the impression that these were on the increase. The Protestant Reformation, coupled with the intensified Turkish threat (interpreted as God’s portent about Christendom’s imminent demise), transformed the culture of monsters and prodigies. The explosive events in Germany accompanying the Protestant Reformation seemed to its supporters to be God’s sign that the world was living in its Last Days. ‘This is now the last age, when the Gospels are resounding, and crying out against the Pope,’ wrote Luther. His opponent Johannes Cochlaeus depicted Luther in 1529 as the seven-headed monster of the Beast in the Book of Revelation. Lutheran propagandists responded with the ‘Seven-Headed Papal Monster’, a woodcut depicting a beast with its claws trampling the Gospels underfoot and its mouth (like a lion’s – a reference to Pope Leo X) threatening to swallow up countries. Reformation turmoil sensitized contemporaries to the signs in nature that what was happening was part of God’s providential plan.

As the controversies of the Protestant Reformation deepened, so did the debate over monsters, prodigies and portents. Protestants saw them as warning signs from God, but Catholics interpreted them as false signs from the Devil. Religious tensions led both sides to enlarge the scope of divine intervention and to sharpen the distinction between what could be ascribed to divine forces and what might be explained by irregularities in nature itself. The natural histories of portents and prodigies, prolific from the later 1550s, contributed to a sense of apocalyptic anxiety. Their authors developed a pseudo-science of ‘teratoscopy’ (the study of prodigies in nature). Philipp Melanchthon’s relative Caspar Peucer published a synthesis in 1553, trying to separate out ‘holy prophecies’ from ‘natural predictions’ and the ‘ruses of Satan’. His objective was to demonstrate that, although the Devil had vitiated the certainties of divination, there were still signs and portents which could be ascribed to God. In Basel, Conrad Lycosthenes spent twenty years compiling a chronicle (Prodigiorum ac ostentorum chronicon, 1557) of prodigies and portents. He used the terms ‘sign’, ‘prodigy’, ‘miracle’ and ‘manifestation’ interchangeably to describe violent, hideous or strange events, all signs from God. And since a tenth of those which he recorded occurred in the period from 1550 to 1557, Lycosthenes saw his chronicle as proof that Christendom was under threat. The conjuncture between religious and political turmoil and a portent and prodigy literature continued into the first half of the seventeenth century, although in the salons of the virtuosi of the new science it was transposed into a culture of curiosity and divertissement, tinged with scepticism.

Contrasting explanations for unexplained phenomena also existed from among those who studied alternative currents in ancient philosophy. The works of the Epicureans, Stoics, Platonists and Pyrrhonists became available in printed editions, while Hebraists explored the esoteric philosophy and techniques of the Kabbalah. Amid this period of classical discovery, the life and works of Aristotle acquired a historical perspective. As the alternatives to Aristotelian philosophy came to the fore, they provided a credible basis from which to attack Aristotle himself. Neo-Platonists, in particular, thought that the ‘marvellous effects’ which occurred in nature could be explained by an alternative model of how the universe worked. Life-forces existed, immanent in nature, which could not be accounted for in terms of Aristotelian categories of matter and form. The world was a ‘feeling animal’. The ‘souls’ of animate nature were instruments of these energies. The latter (often described as a pneuma, not exactly matter and not quite mind) linked the microcosm to the macrocosm, bodiless and embodied things in a mystic harmony. These harmonies could be detected by an adept through the power of natural magic. Through music, mathematics and spiritual and psychological magic, the magus could enter a higher world of figures and celestial influences in which the deeper truths which God had placed in nature could be accessed by human imagination.

The agenda of natural magic was ambitious. In reality, Neo-Platonists differed from one another on both the definitions and the details of how one might proceed. They had no common platform. On their own, they could not supplant the Aristotelian consensus. They were always vulnerable to the charge of being cheats and impostors, deluding people with the pretence of understanding occult celestial forces. But their impact was real enough, at least until the demands for an explanation of the universe that relied on more transparent and imposed laws of nature began to make themselves felt towards 1650. Neo-Platonist explanations seemed to be supported by a more powerful mathematics, capable of representing complex relationships in geometrical and algebraic form. The adepts of the new chemical philosophy also found in Neo-Platonic explanations a language and vision of animist complexity which provided a basis for attempts to explain chemical change. Neo-Platonists used their anti-Aristotelianism as a rhetorical platform to their advantage. More, they offered a plethora of examples of their explanations at work in nature. They emphasized at every turn that (unlike Aristotelians) their aim was to bring about something practical. They believed in and practised experiments. Above all, Neo-Platonists had all-embracing explanations for natural phenomena that did not rule out God’s power in the universe. On the contrary, their picture of an animate nature reinforced the sense that God was close by, a great artificer in nature, at work in the forces of his universe. By the same token, however, Neo-Platonists had to admit that such life-forces were capable of being suborned by those who chose to be instruments of the Devil. And in the Manichean atmosphere of the Post-Reformation, the Devil was becoming a more significant enemy in what remained of Christendom.

In 1533, Heinrich Agrippa published an enlarged edition of his Occult Philosophy (De occulta philosophia) which, through its frequent reprinting and many translations, defined ‘natural magic’. Agrippa was an artful vulgarizer and drew on the works of Italian Neo-Platonists (especially Giovanni Pico della Mirandola and Marsilio Ficino), Jewish Kabbalists, Hermes Trismegistus, Pythagoras and Zoroaster, which he encountered during the six years he spent in North Italy in imperial service from 1512 to 1518. ‘That magic is natural,’ he wrote, ‘which having observed the forces of all things natural and celestial and having examined by painstaking inquiry the sympathy among those things, brings into the open powers hidden and stored away in nature.’ ‘Magic’ was that which ‘links lower things as if they were magical enticements to the gifts of higher things’. ‘Astonishing wonders thereby occur,’ he continued, ‘not so much by art as by nature to which – as nature works these wonders – this art of magic offers herself as a handmaiden.’

Magic was not what magicians do, but what nature accomplishes with their help. By describing magic as the link between lower and higher bodies, Agrippa emphasized astrology. ‘Magic is so connected and conjoined with astrology,’ he said, ‘that anyone who professes magic without astrology accomplishes nothing.’ Agrippa did more than anyone else to give respectability to ‘occult’ philosophy in the sixteenth century. To illustrate the potential of natural magic he interspersed his philosophy with experiments. He used magnets, heliotropes, basilisks, dragons, electric ray fish, mandrake, opium, hellebore and dragon’s wort (tarragon) to exemplify the strange powers in nature which he claimed to be able to understand and harness through natural magic.

Agrippa knew that such power in the wrong hands could become sorcery. His book was published in defiance of the Dominican inquisitors, alert to the spectre of demonology as witchcraft prosecutions became more prevalent. Agrippa was careful to include in the revised 1533 edition a recantation of magical philosophy, one which he had initially published seven years previously as part of his On the Uncertainty and Vanity of the Sciences (De incertitudine et vanitate scientiarum), another famous book which denounced human arts and sciences (especially astrology) as useless, particularly in the hands of scholastic theologians and avaricious clerics. Read in the context of the Lutheran Reformation, to which he was inclined, Agrippa wanted to say that there was no real knowledge beyond faith in Scripture. Set alongside his views in Occult Philosophy, the perplexity in which he left his reader made the book notorious, contributing to accusations of his supposed dealings with the Devil. Some details around the legendary Dr Faustus are attributable to Agrippa.

Occult philosophy was especially influential among the growing numbers of nonconformist thinkers in Europe whose careers as physicians, alchemists and astrologers provided them with a platform for their speculations. Girolamo Cardano, a trained physician from the universities of Pavia and Padua, established a name for himself as a mathematics teacher in Milan before setting up a successful medical practice. He already had a reputation as an algebraist who had probed the laws of probability before he published On the Subtlety of Things (De subtilitate rerum, 1550). The publisher’s blurb said that the book offered its readers ‘the causes, powers, and properties of more than 1500 varied, uncommon, difficult, hidden and beautiful things’. Cardano himself emphasized that reading his book was like going into a cabinet of curiosities, warning readers of its 1554 edition (by which time it had expanded to offer ‘2,200 very beautiful things’): ‘many will read, but few, if any, will understand everything written here’.

Cardano was a serious astrologer, deploying an observational knowledge of the movements of the sun, moon and known planets to predict and explain the history of the world, and to cast horoscopes for the alive and dead. At the same time, he knew the dangers that lay in store for his reputation. His ‘rivals’ would cause him ‘harm’ if his predictions turned out to be false. Always charge a high fee for astrological consultations, he advised, and never publish anything, ‘for those who do so make themselves infamous even when their predictions are true’. Cardano did not follow his own advice, however, and his first publication was a Prognostication (1534). The great conjunction of Saturn and Jupiter which occurred that year predicted ‘that the world must soon undergo a complete renewal. Pay attention. Sacred Scripture and astrology have shown us, without doubt, that our insatiable rapacity must soon come to an end.’ Four years later, he became the first astrologer to publish a collection of ‘genitures’ (or horoscopes) of famous people, alive and dead, based on the disposition of the planets at their birth. The result was a provocative work of literature, in which the faults and fortunes of the famous (they included Nero, Luther, Dürer and Savonarola) were exposed, but found to lie in the stars. The work invited the barrage of criticism which it duly received. But it also opened the door to invitations from princely clients (including King Edward VI of England) who were persuaded that it was better to know what the stars had in store before it happened to them.

Cardano distanced himself from Aristotelian natural philosophy. He wrote and rewrote his autobiography, examining his life as though it was a scientific subject in its own right. Occult powers had psychic as well as physical impact, and his interest in dreams as ‘an admirable form of divination’ was as considerable as his theories of metoposcopy (predictions of human behaviour from characteristics of the forehead) and chiromancy (predictions using palm-reading). Like Agrippa, he was aware of the dangers that could occur when magical power fell into evil hands. He emphasized that it was only when such knowledge was put to practical use to improve the condition of human life that it could be regarded as legitimate. Cardano’s On Subtlety was the object of an attack by another natural philosopher, Julius Caesar Scaliger, in 1557. When challenged, Cardano shrouded himself with the justification that mystic inspiration, beyond his own powers of explanation, led him on. That was not sufficient for the Inquisition in Bologna, however, which imprisoned him in 1570 because he had attempted to cast Christ’s horoscope.

The Elizabethan magus-mathematician John Dee was a devoted astrologer. From his days as a student in Louvain in 1547, he kept notes of planetary positions from which to cast horoscopes. In his first published work (a set of aphorisms on mathematical astrology) he compared the universe to the harmonious resonances of a lyre. Then, following in Agrippa’s footsteps, he explored the Jewish esoteric tradition of the Kabbalah. This taught that Creation descended from the perfection of God down to the imperfect material world. The letters of the Hebrew alphabet, which are also numbers, were the building blocks of Creation and the key to Holy Scripture. By making words numbers, and using Kabbalistic interpretive techniques, the underlying numerical harmonies in the universe could be detected. Monas Hieroglyphica (1564), his most acclaimed work during his lifetime, showed how a geometrical symbol (a hieroglyph) was one from which all other symbols could be constructed. It formed the key to a symbolic system and accompanying exegesis. In his Mathematical Preface (1570) to Henry Billingsley’s popular translation of Euclid’s Elements, Dee turned this Kabbalistic manipulation of symbols into a plea for the application of mathematics to the searching out of all knowledge.

That was a goal he shared with Johannes Kepler, who, abandoning his theological studies, became obsessed with applying mathematics to the discovery of heavenly harmonies. Inspired by a vision which came to him while teaching, Kepler conceived of a hieroglyph, analogous to Dee’s, with which to explain why God had decided that there were only six (known) planets, and why he should have determined that they have orbits. Kepler was district mathematician in Graz until he visited Rudolf II’s imperial mathematician, Tycho Brahe, in 1600 and became his assistant. Following Brahe’s death a year later, he succeeded him to that post in Prague, thereby inheriting his planetary observations (the Rudolphine Tables). Kepler sought an answer to the question about the number of planets and their orbits which explained why things were the way they were in the real world. His hieroglyph was based on the five, regular ‘Platonic’ solids. By the principles of Euclidean geometry, they were the only possible three-dimensional objects with all faces the same. So, when God inscribed those solids into the spheres of the planets, six was the only number of planets that there could ever be, and their orbits relative to each other were inscribed and circumscribed (he followed a Copernican heliocentric picture of the universe) by the shapes of those solids. He outlined this ‘geometrical Kabbalah’ in Cosmographic Mystery (Mysterium cosmographicum, 1596).

Three years later, Kepler began work on his masterpiece, the Harmony of the World. When it was finally completed and published in 1619, Kepler expanded his Neo-Platonic conception of the universe to include the Pythagorean harmony of the spheres. His explanation began with an analysis of musical harmony. There was also a long section on astrological harmonies affecting sublunary nature, for Kepler was a convinced astrologer, albeit critical of simplistic notions as to how planetary conjunctions might dictate what happened on earth. By then, and on the strength of his and Brahe’s astronomical observations, he had convinced himself that planetary orbits were not circular but elliptical, but he managed to explain that too within his Neo-Platonism.

To understand the motions of the planets around the sun, Kepler had recourse to something like magnetic force, as examined by William Gilbert, physician to Elizabeth I, in his On the Magnet (De Magnete, 1600). Scornful of Aristotelian learning, Gilbert acknowledged his debts instead to the mathematical and navigational practitioners in London – those ‘who have invented and published magnetic instruments and ready methods of observing, necessary for mariners’ work and those who make long voyages’. But it was Cardano who led him to his ‘magnetic philosophy’, in which the earth was infused with a hidden energy, a giant magnet, alive and self-moving around its own axis. To prove the case, Gilbert turned to the ‘microcosm’ of the world, the lodestone, and it was at this point that the practitioners provided him with the instruments to carry out ‘experiments’ (his preferred term) by which to tease out what navigators had already discovered for themselves, namely the existence of magnetic North, and the declination of the compass needle at different longitudes.

Astrologers, astronomers, magicians and mathematicians, like cosmographers and naturalists, became respected figures at European courts. Pope Paul III was one of several occupants of the papal throne in the sixteenth century to employ a resident astrologer. Michel de Nostredame (Nostradamus), who acquired a reputation as a medical practitioner at Salon in Provence, began producing his annual almanac in 1550. His Prophecies (or Centuries) followed in 1555. Catherine de Médicis, then queen in France, had been brought up at the Florentine court, which made her particularly well-disposed to judicial astrology and the power of natural magic. She asked Nostradamus to prepare royal horoscopes for her children. When she became queen mother and regent in France, she secured his appointment as court physician and consulted him about propitious moments for her family. Queen Elizabeth’s coronation was held on 15 January 1559, following the horoscope cast for her by John Dee. The queen held him at arm’s length thereafter, but he busied himself as a consultant to the English Muscovy Company and the adventurers colonizing North America. Complaining of slanders against him and protesting that he was innocent of ‘unchristian’ practices, Dee succumbed to the enticements of a Polish aristocrat (Albrecht Łaski), who accepted him for the great magus that he claimed to be, and fell under the influence of an impostor (Edward Talbot, alias Edward Kelley) posing as a spirit medium.

Dee then turned to Emperor Rudolf II and, in August 1584, he and Kelley moved to Prague. He had an audience with the emperor, telling him that through his medium (Kelley) he enjoyed conversations with angels who told Dee that he was God’s chosen prophet. He offered to make the emperor a party to these conversations. If Rudolf repented of his sins and believed in the message that Dee would convey to him, he would triumph over his enemies, defeat the Turk, and become the greatest emperor in the world. The emperor indulged his fascination for clockwork automata, his search for perpetual motion, his alchemy, and his predilection for mineralogical and botanical collecting, attracting to his court the most prominent occult philosophers and alchemists of the day. ‘His Majesty is interested only in wizards, alchymists, Kabbalists and the like,’ said one enemy. Dee, however, was disappointed. Rudolf wanted to maintain religious peace in the fragile political situation of the empire. Dee angled to be the emperor’s magician-confessor, revealing secrets in return for action and commitment. But Rudolf’s interests in magic grew out of passive resignation and spiritual pessimism. At the insistence of the papal nuncio, who was convinced Dee was a ‘conjuror and a bankrupt alchemist’, the emperor expelled him in 1586.

In retrospect, the last years of the sixteenth century were the high-water mark of respectability for astrologers at European courts; their courtly influence declined thereafter. The hidden homologies of the universe, on which their science depended, seemed out of place or irrelevant in the Thirty Years War, where political and military conflicts, the course of which they had failed to predict, were so immediate. Their science required substantial reworking in order to embrace a heliocentric cosmology. Mathematicians offered a more applicable and secure science, not least in relation to ballistics. Astrology and divination remained popular, but learned astrology could hardly survive the mechanistic models of the universe which followed in the wake of the widespread acceptance of Copernicanism. Then again, the Counter-Reformed Catholic Church turned decisively against leading Neo-Platonists at the turn of the century, condemning the writings of their leading philosopher (Francesco Patrizi), burning another (Giordano Bruno) and imprisoning a third (Tommaso Campanella). Even in Protestant Europe, there was a rejection of the occult formulations of its practitioners. Meditating upon Dee’s Monas Hieroglyphica, the Protestant divine Méric Casaubon gave up in despair. ‘I can extract no sense nor reason (sound nor solid) out of it,’ he wrote.

By the early years of the seventeenth century, natural magic had helped to break down the Aristotelian consensus. Natural magicians had extended the intellectual space and respectability for practical knowledge and discovery and created a more positive relationship between philosophers and technical practitioners. The natural magic tradition had broadened the scope and significance of mathematics as a way of understanding the universe. Above all, natural magic had countered the tendency in the Post-Reformation period to regard everything which happened that was out of the ordinary as a supernatural event – a warning sign from God or a demonological force. Magic enlarged the space for understanding the natural.

THE ALCHEMICAL REFORMATION

Alchemical skills and practices acquired great significance. They were essential to the ‘silver age’. The mercury amalgamation process advertised the possibilities of transmutation of base metals into rarer ones. Mint-operators as well as silversmiths and goldsmiths needed the techniques of assaying and cupellation. Alchemists’ know-how was essential to manufacturers of guns, saltpetre, glass, printing ink, bleaches and dyes. Alchemical techniques were increasingly significant in medicine too. But there were no formal alchemical qualifications. Techniques were acquired by a combination of experience and reading the broadening range of manuals, both skills books explaining particular recipes, and compendia of authoritative (often Arabic) texts from the Middle Ages.

Alchemy also became more than an assemblage of techniques and procedures. It formed the basis of a chemical philosophy and medicine. Chemical philosophy linked itself with astrology and natural magic, offering an understanding of God as a divine chemist. The Creation was a chemical process, and the end of the world would be a chemical culmination. Chemical medicine openly challenged the pre-eminence of Galenic medicine. The response of the medical establishment was predictably hostile, exploiting the notoriety which traditionally surrounded alchemists, saying they were fraudsters. The fortunes of chemical medicine and philosophy were inextricably linked with those of the Protestant Reformation, and one person in particular.

The individual was Theophrastus Bombastus von Hohenheim, who advertised himself in an early publication, the Predictions Pronounced upon Europe (1529), as ‘Paracelsus’ – i.e. ‘Surpassing Celsus’, the physician of ancient Rome. In his life and career he rejected the prevailing knowledge establishment. Born at Einsiedeln, a small town near Zürich, he moved with his father, a physician, to Villach in Austria, where he worked as an apprentice in the nearby Fugger-owned silver mines before training as a physician, serving as an army surgeon, and becoming physician by appointment to the city of Basel. He drew on his experiences in publications on miners’ ailments, new ways of treating wounds and the cure of syphilis. He proclaimed that true knowledge came not out of medical textbooks but from ordinary people (‘I have not been ashamed to learn from tramps, butchers and barbers’) and from practical experience (‘I tell you, one hair on my neck knows more than all you authors, and my shoe-buckles contain more wisdom than both Galen and Avicenna’).

His appointment at Basel entitled him to lecture on medicine at its university. To the scandal of the medical faculty, he refused to wear an academic gown, lectured in his German-Swiss dialect rather than Latin, ignored the textbooks and, in a gesture of public defiance redolent of Luther’s five years earlier, threw one of them (Avicenna’s Canon) on a bonfire. Not long after he was expelled, resuming an exotic life of travel which his later publications exalted as the only true way of finding things out. ‘According to me, and not according to you’ was his taunt to the medical establishment. He had already visited Italy, Holland, Prussia, Poland, Scandinavia and the Levant. Now he made his way through Alsace, Bavaria, Bohemia and Austria, which is where he died (in Salzburg). He did not, however, live the life of the conventional wandering scholar. There were stories: of his excessive drinking, filth and possible madness; of his turning up dressed as a beggar, or a peasant or a noble; of his preaching unorthodox doctrines to Swiss peasants (Appenzell, 1533), and raging against the authorities.

For Paracelsus, medicine was a form of protest. Prognostications, based on conjunctions, eclipses and comets, account for the majority of the works printed under his name before his death. Christ’s birth had been heralded by a new star and the turmoil of religious change and (as he saw it) the likelihood of imminent social collapse would necessarily be reflected by portents in the sky, signs of the coming Day of Judgment. Such a new star (Halley’s Comet) had made its appearance in 1531. Paracelsus sighted it on 21 August in the sky above St Gallen. ‘All destructions of monarchies . . . are announced by portents and signs,’ he wrote. Yet Christ had worked healing miracles; so a return to the true word of Christ involved a recovery of Christian healing. Medical reformation must begin with a cleansing of its temple and the exposure of the greedy and incompetent medical fraternity. In his two short tracts on syphilis, he contrasted doctors offering an ineffectual but expensive remedy (guaiacum, an American wood, whose supply was controlled by the Fuggers) with simple therapies (laudanum as a pain-killer and mercury for syphilis, mainstays of Paracelsian treatments). Vanity and avarice were Paracelsus’s twin enemies of a medical reformation in which service to the common weal and care for the least privileged in the community with simple remedies lay at the core. Reacting to the contemporary taunt that he was the ‘Luther of medics’, he responded: ‘Am I a heresiarch? I am Theophrastus . . . the monarch of physicians,’ who had turned his back on the ‘stone-church’ of the medical establishment in favour of peasants (in support of whose cause, Paracelsus had briefly been arrested).

The majority of Paracelsus’s prolific writings did not see the light of day until after his death. ‘Paracelsianism’ was guaranteed a long afterlife by their gradual publication and by the controversies surrounding their reception. When he fled from Basel, he left many papers in the hands of his amanuensis, who became the publisher Johannes Oporinus. Oporinus disliked Paracelsus’s private life and saw no point in publishing his outpourings in Swiss-German. They languished until Adam von Bodenstein, the son of a radical Protestant and physician, became a convert to Paracelsian chemical medicine after being cured of a tertian fever by its means. Expelled from the University of Basel for his ‘heretical and scandalous books’, he published Paracelsian treatises. A physician in Strasbourg, Michael Schütz, became another convert to the cause, collecting and publishing Paracelsian works. Not until the early years of the seventeenth century was the Paracelsian corpus available in print, mostly written in rebarbative Swiss-German and peppered with strange jargon. A cottage industry of Paracelsian lexicons emerged to make sense of the new ‘chymiatria’ (iatrochemistry). Little by little, however, the key Paracelsian notions became clear – notably the three ‘principles’ in nature (sulphur, mercury and salt), the equivalent of the Trinity. The fundamental chemical process was separation, and it explained processes in the macrocosm (the Creation) as well as the microcosm (the digestive system). ‘Chrysopoeia’ and ‘argyropoiea’ (Paracelsian mumbo-jumbo for making gold and silver) were about progressive distillation and the removal of slag during the refining of metals.

Despite opposition from medics (among his most vocal critics was Thomas Erastus at Heidelberg), the influence of Paracelsian medicine grew in German lands in the years before the Thirty Years War. The remedies attached to his name seemed to work, and chemical physicians offered the prospect of uniting hands and minds in the discovery of the secrets of nature to the public good. Chemical physicians and alchemists enjoyed the patronage of German princely courts. Ernst von Bayern, archbishop of Cologne, was a great Paracelsian supporter. Duke Julius of Brunswick-Wolfenbüttel was a patron to Paracelsians. He regarded alchemists as key figures in his efforts to exploit the mineral resources of his dominions, rationalize the state and maximize its economic potential. Elector August of Saxony invested heavily in alchemical books for his own and his wife Anna’s use. His promotion of chemistry, chemical medicine and horticulture was reflected in Dresden’s court festivals. Not to be outdone, Duke Frederick of Württemberg established a mining city (Freudenstadt) and built himself a chemical research facility in the ducal gardens at Stuttgart. The chemical reformation increasingly became the preserve, however, of Protestant courts and an agent in their struggles.

Conventional physicians in Germany accommodated themselves to chemical medicine, excising the magic and religious unorthodoxy of Paracelsian ideas and their attack upon Galen, while quietly adopting the iatrochemistry. Outside Germany, the medical opponents of Paracelsianism concentrated on discrediting its proponents and debunking its credentials. In France, Henry IV’s physician, Joseph Du Chesne, tried to show how Paracelsus’s three principles could be found in Hippocrates. Published in 1603, his book was denounced by the Paris medical faculty. The turf-war between Du Chesne’s supporters and his detractors was still being fought a generation later, Richelieu cautiously sustaining the chemical physicians against the medical establishment. Meanwhile, other opponents of Paracelsus assaulted his alchemy. In the same year that Du Chesne published his book, Nicolas Guibert printed his Alchemy Impugned by Reason and Experience, in which Paracelsus was described as ‘the most foul and absolute prince of liars who ever was, is, or will be, excepting the Devil’.

A similar battle was underway across the Channel, where the Galenist-trained physician Thomas Muffet returned from Basel as a Paracelsian acolyte. Muffet proposed Paracelsian remedies for the London College of Physicians’ licensed Pharmacopoeia. He also specialized in that part of the natural kingdom whose variety most baffled contemporaries: insects (‘Little Miss Muffet’ of the nursery-rhyme being his daughter). But his proposed changes were not implemented and, by the later 1620s, conservatives had the upper hand at Charles I’s court as well as in the college. Charles’s physician was William Harvey, and he ‘did not care for chymistry’, dismissing newfangled medics (‘neoteriques’) as ‘shit-breeches’.

These quarrels masked the extent to which Galenist physicians quietly adapted to new remedies. That was particularly the case in the Low Countries, where chemical philosophy had an impact on medicine, chemical research and industrial processes. Faculties of medicine could control curricula and license physicians but they could not stifle public interest. Galenic medicine felt under threat. In Germany, debates became dominated by pure-of-heart Paracelsians in the early seventeenth century. Reflecting contemporary religious and political tensions, Johann Valentin Andreae, the Lutheran pastor from Württemberg and author of Christianopolis, composed a spoof pamphlet entitled the Chemical Wedding of Christian Rosencreutz. Published in 1616, it used alchemical allegories to represent Protestant hopes for a new golden age. By then, several publications, circulating from Kassel and perhaps also by Andreae, had introduced the public to Christian Rosencreutz, a talented alchemist and member of a secret Brotherhood of the Rosy Cross. Under the fiction of this brotherhood and its mythical adept, the chemical reformation became a dream for a more fundamental transformation of society. Repackaged, the dream would resurface on English shores in the wake of the English Civil Wars.

SEEING AND BELIEVING

One of the criticisms levelled against the mythical Rosencreutz was that he was too ‘curious’. Curiosity, the cousin to libertinism and atheism, was ‘the vanity of the eye’. That was the title of a book by an English cleric, George Hakewill, published in 1608 and written for someone who had gone blind. Contemporaries celebrated all that could be discovered in the world around them, just by looking. Hakewill countered by blaming sight for everything that was wrong in it: ambition, gluttony, theft, idolatry, jealousy, contempt, envy and witchcraft. He had spent time in Calvinist Heidelberg where the Protestant Reformation was acutely conscious of the dangers of idolatry, Catholic rituals being regarded, wrote Hakewill, as ‘superstitious worship-in-the-eye service’.

Theologians and moralists were not sure how to respond to ocular hegemony. In Counter-Reformed France, some advocated spiritual withdrawal from the world, a way of not ‘seeing’ it, while the Lutheran superintendant of Hamburg, Joachim Westphal, lectured the clergy about the importance of avoiding meddlesome curiosity – in politics, religious controversy, but also in natural philosophy. For his part, Jean Calvin, who opposed Westphal on the subject of predestination, issued his warning against astrologers in 1549. Calvin did not deny that the heavens influenced what happened on earth, but he was convinced that human beings could not interpret what the signs meant, because God had not chosen to share that knowledge with us. We should adopt a ‘learned ignorance’, rather than presume to trespass on the Almighty’s providential disposition. To imagine that we could explain portents and predictions was to step into a ‘labyrinth’ and open the door to the Devil’s deceits.

Curiosity corroded Christendom. For all that philosophers, naturalists and alchemists celebrated the art of looking, the reality was that it was not straightforward. Everyone knew that vision could be radically impaired, and that humoral imbalances could result in delusions. Jugglers and artists could persuade the eye that it was seeing something that was not really there. What were perspective drawings, anamorphic representations, theatrical sets and prisms if not delusions? Optical effects were a common feature of magic – and telescopes and microscopes were no different from other optical magic. Francis Bacon provocatively included both ‘perspective houses’ (i.e. observatories) and ‘houses of the deceit of the senses’ (i.e. theatres) among the research facilities in Solomon’s House on New Atlantis. The Devil was especially adept at deceiving us into thinking that what we had seen was real. How else did witches, known to be in bed, fly off to attend their sabbaths? The difficulty in interpreting what had been seen was the problem for interpreting apparitions and monsters; but it equally existed when it came to the perplexing issues of ghosts and dreams. The insecure status of how to interpret what we saw posed a danger because it confused the true from the false. Both the Protestant Reformation and the ‘new learning’ were about distinguishing one from the other.

Ocular hegemony was asserted in the anatomy theatre. Physicians engaged with greater enthusiasm in dissection, jostling with surgeons and demonstrators. Anatomical theatres constructed for teaching purposes in medical faculties increased after the publication by the famous Flemish anatomist Andreas Vesalius of his On the Fabric of the Human Body (1543). The book was based on his own anatomical lectures, attended by students, to whom he played the showman. He allowed the audience to handle the organs as he removed them from the body: ‘Surely, lords, you can learn only little from a mere demonstration, if you yourselves have not handled the objects with your hands.’ ‘I see’ is a refrain in the text, especially when Vesalius proved that Galen had passed off information taken from animal anatomies as something which occurred in the human body. Almost ninety years later, a prosperous physician and magistrate in Amsterdam, Dr Nicolaes Tulp, commissioned a portrait of himself and several surgeons engaged in an autopsy from a young artist, Rembrandt van Rijn. The resulting picture is not a simple celebration of what could be seen. The painter depicts Tulp not looking at the body himself, but rather holding the splayed-out muscles and ligaments of the corpse’s hand in his own (the artist reflecting an engraving in Vesalius’s anatomy), an anatomist in meditation. His companions stare intently, but at a copy of an anatomy book to one side. Rembrandt depicted a lesson in contemplation of how wonderfully God made nature and man.

Celebrating God in nature was the way by which contemporaries justified their curiosity in the world around them. By the end of the fifteenth century, ‘natural theology’ was used for the argument that the defence of the beliefs which underlay Christendom could be based on the evidence of God as Creator. The argument was pertinent when it came to converting Muslims, Jews or even Indians in the New World, since it represented a starting-point with which they could all agree. It was also the title of an early printed book by Raymond Sebond, made famous in the sixteenth century by Michel de Montaigne’s translation of it into French in 1569. Montaigne conceded that natural theology raised a big philosophical issue, since it relied on the evidence of the human senses, which could easily be misled. So his Apology for Sebond’s natural theology, composed in the 1570s, constituted the longest contribution to his Essays (1580). Christianity, Montaigne argued, depends on faith and grace, and not on reason. The human senses are fundamentally flawed and capable of being deceived, and by nature itself. Human reason was equally fallible. We can no more control our minds than our bodies. ‘To judge the appearances that we receive of objects,’ he wrote, ‘we would need a judicatory instrument; to verify this instrument, we need a demonstration; to verify the demonstration, an instrument. We are thus in a circle. Since the senses cannot decide our dispute, being themselves full of uncertainty, it must be reason that does so. No reason can be established without another reason: there we go retreating back to infinity.’ Elsewhere, and especially in his later writings, Montaigne suggested that whatever truth we might establish lay with simple people – the Brazilian Indian, for example, ‘fit to bear true witness’ because he was ‘so simple that he has not the stuff to build up false inventions and give them plausibility’. Truth lay, as Paracelsus (and Rabelais) said it did, in the mouths of tramps, butchers and barbers.

Montaigne’s circular argument was derived from a book, published in 1562, by Henri Estienne. It was a Latin translation of the Outlines of Pyrrhonist Philosophy (Sexti philosophi Pyrrhoniarum hypotyposeon), the doctrines of Pyrrho as put together by a Greek philosopher and historian, Sextus Empiricus. At the heart of its various propositions was the denial that sensory experience could lead to a scientific knowledge of the external world. It was not simply that our five sensory receptors are limited and inaccurate but that (as Montaigne said) one person’s are inaccurate in a different way from another’s, and there was no way of reconciling them. Radical doubt along these lines became something of a preoccupation in French intellectual circles in the first half of the next century, reflected in the controversial On Wisdom (De la sagesse, 1601) of Pierre Charron and, most famously, in René Descartes’s First Meditation, written in the 1630s. If we could no longer agree among ourselves as to the evidence of our own eyes, what chance was there for agreeing about what a citizen’s role in the state was, or about what was right and wrong? Those were questions which the politico-religious conflicts of the later sixteenth and early seventeenth centuries raised. In their wake, the answers seemed to lie, not in engaging with the world and collaborating as citizens to make the commonwealth a better place, but in separating faith and reason and in detaching oneself from the political world, leaving rulers to keep the peace by force of arms and to determine what was public morality.

Scepticism was taking root, however, at a time when contemporaries ‘knew’ more and more. There were more facts around, and the European sense of ‘fact’ (as something that occurred, or was seen to be the case) made its first appearance in Italy in the later sixteenth century. For Galileo, de facto (di fatto) meant just that. ‘Facts’ were what, for Francis Bacon, experiments could prove. There was a recourse to factual representation of the real world too: paintings from life, true engravings and veritable histories. At the same time, there was more awareness of paradox, in the sense of something that was contrary to what was commonly seen, or regarded, as fact. The paradox at the heart of disintegrating Christendom was that, as Europeans knew more, it made less sense to them.

THE ADVANCEMENT OF LEARNING

Scientific certainties were taught at the universities, the forefront of Christendom’s intellectual life. By 1500, there were seventy-eight institutions that offered a studium generale – a place where students from anywhere in Christendom could study under professors within a teaching programme that offered not only arts subjects (the trivium of grammar, rhetoric and logic, followed by the quadrivium of arithmetic, geometry, music and astronomy), leading to a degree as master of arts, but at least one of the higher faculties (theology, law or medicine), where students studied for a doctorate. The majority of these universities were old foundations, established by bulls from the papacy or charters from the emperor. But over thirty of them were not a century old, founded by princely patrons who understood that university education had become an important part of the formation of young men in the upper social echelons. Universities had no difficulty in attracting increasing numbers of Europe’s notability in order to educate the state officials, lawyers, physicians and clergy of the future. Moreover, their students became imbued with the humanist values which gradually permeated through arts faculties. Germany stood out in the establishment of new schools of learning. The major universities were, to varying degrees, connected to the Church. In Paris, Oxford and elsewhere, theology was the pre-eminent higher faculty. That was because scholarship was about truth, the rational foundation for the belief-community at the heart of Christendom. A degree from a university was studied for in similar ways, and in accordance with a curriculum that was recognizable throughout Christendom.

University expansion continued at a brisk pace beyond 1500, driven by the same pressures that had been at work in the previous century. By 1650, the number of establishments had more than doubled. The student cohorts probably increased even more. But by 1650, a university degree was no longer universally recognized, the result of religious and political division. The Holy Roman Emperor refused to acknowledge the University of Leiden, founded by the Dutch in 1575, and so did Philip II, in whose name the university claimed a (forged) deed of foundation. Religious dissidents went abroad to study, their influx leading to the foundation of new establishments (Irish Catholics in colleges and seminaries in France, the Low Countries and Rome; Huguenots in Geneva, Sedan and Orange). Rulers used institutions of learning to validate religious change. In 1527, the Landgrave Philip of Hesse established a college without papal privilege or imperial approval in order to train the clergy for the Lutheran Reformation. Trinity College Dublin was founded in 1592 as a Puritan educational adjunct of the Protestant English ascendancy. Sweden established or re-founded colleges of higher education and universities as part of its attempts to integrate the conquered territories of northern Germany and the Baltic into its state.

In addition to universities, there were other institutions that offered tertiary education, many of which did not award degrees at all. This was especially the case in Protestant Europe. German emperors refused Calvinist high schools the right to confer degrees. For their part, Genevan pastors and magistrates staked their claim to be different from traditional universities by establishing an ‘academy’, delivering simply a testimonial of Protestant beliefs and behaviour at the conclusion of a period of study. By not awarding degrees, faculties became less important and the possibilities for pedagogic and curriculum innovation greater. One of the most influential models was that put in place by Johann Sturm at the Strasbourg school which he directed for over forty years from its inception in 1538. He drew on his teaching experience in the colleges of the University of Paris. Strasbourg’s academy was like a secondary school and further education college rolled into one, offering a humanities school, organized into classes, with a university-style superstructure of liberal arts teaching on top, delivered by university chair-holders giving courses of instruction in different subjects on a rotating basis. The aim was to integrate sound learning and humanist values with Protestant piety and the ability to analyse material and construct persuasive arguments – a key skills-set for the administrators, teachers and preachers of the next generation in the commonwealth.

Although more universities with rights to award degrees existed in Catholic Europe, there too the range of higher educational provision broadened. The Jesuits also borrowed from the Paris collegiate model. Lagging initially somewhat behind Protestant foundations, by 1600 they overtook them, their colleges offering the most widespread and coordinated programme of further and higher education in Europe, one that universities could not match. But where the Jesuits had higher educational facilities, they were generally limited in nature, having an arts faculty with a faculty of theology tacked on. Only a small minority became degree-awarding institutions (for example, Olomouc in 1581, Bamberg in 1648). Other Catholic orders involved in higher educational provision (seminaries, for instance) chose mostly not to establish universities awarding degrees.

In both Protestant and Catholic Europe, those seeking an education for their sons readily understood the differences in objectives and attainments of these various establishments, aware that study at an academy (such as the flagship academy at Herborn in the Calvinist Wetterau counties of Rhineland Germany) might count for more than a university degree. They sought a ‘general education’ (Paedagogium) for their offspring, promoting ‘learned and eloquent piety’. Only a small minority of students were expected to go on to study in the higher faculties. The objective was not the construction and transmission of an edifice of scientific certainty. They did not need the elaborate scaffolding of Aristotle’s Logic (the Organon) to achieve their goals.

Fortunately, more elementary primers were to hand. In Lutheran Europe, Melanchthon wrote several Dialectics, which became very popular. In Calvinist Europe, it was the Dialectics of a teacher at the University of Paris, Pierre de la Ramée (Ramus), that swept the board. Ramus had taken his Master’s degree there in 1536, defending as his thesis: ‘Whatever is affirmed from Aristotle is contrived’. Eight years later, he published a frontal assault upon Aristotle’s Logic, and then his substitute for it, the Dialectics (Dialecticae Partitiones, 1543). Ramus offered something simpler – a tenth the size of Aristotle’s text. He sought to make logic into an instrument of communication (‘dialectic . . . an art which teacheth to dispute well’). Rhetoric was separated off, leaving the student to concentrate on how to define the topics of a discourse and then arrange them. Students were taught the basics: to proceed from the general to the specific, from definitions to examples. Ramus’s practice of dividing subjects into two main parts, and then further subdividing each of them (creating dichotomized tables) became, in the hands of Ramist-educated students, over-contrived. His proposed reform so incensed the teachers in Paris that they prosecuted him for undermining philosophy and religion. The king ordered a royal commission which, in 1544, prohibited Ramus’s books and banned him from teaching. He turned to mathematics, and had a hand in another pedagogical reformist treatise, the Rhetoric (1548), of his former student Omer Talon.

The ban on his teaching was eventually rescinded and in 1551 he became professor of philosophy and eloquence at the prestigious institute for humanist learning, established by Francis I, the Collège de France. From that haven, Ramus launched frontal assaults on the University of Paris, where professors purchased their posts and the costs of a college degree were beyond those of modest means. Venal professors took bribes in return for dissecting dead Scholastic doctrines. His solution was to recruit professors on a competitive basis, pay them from the public purse and reform the syllabus. He created many enemies, and his Protestantism made him a target for them at the massacre of St Bartholomew, where he died in the bloodshed. The success of the Ramus/Talon textbooks was considerable. They would be the foundation-stone of the education at Herborn (and other Calvinist academies), where one of its philosophy professors, Johann Heinrich Alsted, researched an ambitious encyclopaedia of the sciences, rooted in Ramist pedagogy but drawing on other traditions too, with the aim of coordinating knowledge and reformation. There would be some 800 editions and adaptations by around 1650, and almost half that number again of textbooks by other Ramist educators, all for use in Protestant, mainly Calvinist, Europe.

The success of Ramist pedagogy was matched, in due course, by that of the Jesuits. Their model curriculum (the Ratio Studiorum, 1599) was widely followed by colleges – to the degree that they had competent teachers to deliver it. Because it elevated the significance of the quadrivium (arithmetic, geometry, astronomy and music), it needed teachers with specialist skills. Partly because of confessional competition, the range of curriculum and teaching innovation in Europe’s academies and colleges was impressive. Generations of articulate and versatile Europeans were educated. But such innovation threw the spotlight back on universities, where the demands of the higher faculties for a traditional formation restricted change. There was more evidence of change than was apparent from the outside, but it did not stem the rising tide of criticism against universities for defending an ‘old’ learning.

That critique began from a central plank in the humanists’ platform, which was that they were recovering ancient texts and learning which had been ignored by medieval Scholastics in a barbarous ‘Middle Age’. The humanist history of learning was an inverted curve of ancient greatness, medieval decline and contemporary renaissance. The rejection of Scholastic learning in favour of Antiquity became a rhetorical commonplace especially to promote subjects which were not traditionally seen as scientific. In Andreas Vesalius’s treatise on anatomy, as in Giorgio Vasari’s Lives of the Artists, ‘old-fashioned’ Scholastic learning became a foil to advertise what was exciting in humanist rediscovery. ‘Let us imagine a teacher of a university who died a century ago, and now returned among us,’ declared Ramus in a public lecture, published in Paris in 1564. ‘If he compared the efflorescence of humanist learning and the sciences of nature in France, Italy and England as they have developed since his death, he would be shaken and astonished’ by the changes. ‘It is almost as if he raised his eyes from the depth of the earth to the heavens and saw for the first time the sun, the moon and the stars.’

By 1600, the critique went a stage further. The learning of the ancients was not simply being recovered, but being surpassed. New worlds, devices, technologies and philosophies had been discovered, and they were commodified as ‘novel’. A series of engravings was issued in Antwerp in the early seventeenth century to designs by Jan van der Straet under the heading ‘New Discoveries’ (Nova Reperta). The frontispiece illustrating the first series depicted the Americas, the compass, gunpowder, the clock, guaiacum, distillation and silkworm cultivation. Later sheets illustrated the manufacture of cane sugar, finding longitude by the declination of the compass and copper engraving. There was the beginnings of a debate between the ‘Ancients’ and the ‘Moderns’ (one in which George Hakewill staged an appearance on the side of the ‘Moderns’). Novelty was not a curse and the advance of learning could be seriously promoted.

The Proficience and Advancement of Learning (1605) was the title of Sir Francis Bacon’s first prospectus for ‘discovering’ new knowledge. The son of Sir Nicholas Bacon, a prominent Elizabethan courtier and Keeper of the Great Seal, Francis was trained in the law, and he expected to follow in his father’s footsteps. Unfortunately, his career stalled and so, like others of his day, he occupied himself with projects which might interest the state and promote his fortunes. They included plans for a state-sponsored research library, botanical gardens, a laboratory and a museum of inventions. He was frustrated when these came to nothing. With the advent of King James I (who promoted himself as ‘Solomon’, a divinely inspired royal sage), he published a prudent ‘mixture of the new and the old’, linking the discovery of the New World to a reform of learning. ‘Proficience in Nauigation, and discoveries,’ he wrote, ‘may plant also an expectation of the further proficience and augmentation of all Scyences, because it may seeme that they are ordained by God to . . . meete in one Age.’ He cited a prophetic verse from the Book of Daniel: ‘Many shall run to and fro, and Knowledge will be increased.’ Meanwhile, he wrote the outline of what would appear fifteen years later in Latin as the Novum Organum (New Organon, 1620). By that date, however, Bacon was a busy man, having been appointed attorney general in 1613, and Lord Chancellor in 1618. The book, dedicated to James I, was unfinished; but that was the point. The preface said that he aimed to provide the equivalent of a compass to point the way across an unknown ocean, comparing the voyage to be undertaken to that of Columbus. The book’s frontispiece was of a ship in full sail, passing through the twin Pillars of Hercules (carrying the motto ‘Plus Ultra’) to discover new lands of knowledge.

The work was divided into two books. The first was a scathing attack on the ‘vices’ of traditional learning (‘phantastical’, ‘superstitious’, ‘contentious’), with Aristotle the target. In the second book, he offered his alternative (‘middle’) way. To explain it, he drew an analogy from the bee. It ‘gathers its material from the flowers of the garden and field, but then transforms and digests it by a power of its own. And the true business of philosophy is much the same.’ Discovery was a collaborative process in which diligent human beings collected information about the real world in store-houses of ‘natural histories’, turning it through the art of experiment (learning the ‘secrets of nature’ by ‘constraining it’) and logical induction into fruitful and productive knowledge. Bacon deliberately wrote his ‘logic’ as a series of disjointed ‘aphorisms’ – each one designed to detonate thoughts in the brain. Aphorism 124 ran: ‘For I am building in the human understanding a true model of the world, such as it is in fact, not such as a man’s own reason would have it to be; a thing which cannot be done without a very diligent dissection and anatomy of the world . . . Truth therefore and utility are here the very same things.’ If Bacon hoped to engage Solomon in his enterprise, he was to be disappointed. Within a year of the publication of the New Organon, his enemies secured his impeachment by Parliament and he was disgraced. Appreciated on the continent of Europe for its ferocious attack upon Aristotelianism, Bacon’s project became, in a popularized form, a platform for those who sought change in England at the time of the English Civil Wars.

COPERNICAN COSMOLOGY

Nicolaus Copernicus’s On the Revolutions of the Celestial Spheres was published in 1543. Copernicus had studied in Cracow and Bologna, but retired to Frauenburg, a cathedral city on the Polish Baltic coast, in 1503. Astronomy was part of the core curriculum, taught from textbooks that explicated the Ptolemaic model of an earth-centred universe in which the planets moved around the earth on epicycles, whose centres inscribed the circles that constituted the bodies of the planetary spheres. The epicycles (and associated ‘equants’, formulae for planetary movement during the epicycle) accounted for variations in the speed and brightness of planets and for their periodic retrograde movement. Ptolemy’s Almagest was available in Latin and Greek versions, but it was regarded as difficult and rarely studied directly. Humanist scholars worked to provide an introduction to it that would make it comprehensible. They also added new observations and calculations since Ptolemy’s were very limited.

Copernicus’s work offered a solution to two problems, one theoretical and the other practical. The theoretical one was the discrepancy between Aristotle’s account of motion (which was that it must always be linear and uniform) and that of Ptolemy (which was an explanation for why planetary motion was non-uniform). Ptolemy’s epicycles and equants created planets whose movement was different from everything else in the universe, like (said Copernicus) a monster whose arms and legs moved separately from each other. The practical problem embarrassed the Church. Ptolemaic astronomy could not accurately compute the calendar and the dates for Easter, and in 1514 Copernicus was invited to Rome to advise upon a solution. He declined, saying that it could not be set right until the problems of the motion of the sun and moon had been solved. Copernicus perhaps knew that part of his eventual solution had already been proposed by Arabic astronomers. But he discovered that you could not displace one part of the planetary system without ‘disordering the remaining parts’. He therefore remodelled all planetary motion with the earth involved in a uniform triple motion (rotation around its axis, revolution about a point near the sun and directional rotation upon its axis) which corresponded to that of the other planets.

Copernicus did not regard this as an armchair exercise. His preface insisted that what he proposed was physically true. The celestial bodies revolved around the sun and in physical spheres, just as they carried the earth. That, however, placed his system at odds with Aristotelian physics, Holy Scriptures and daily experience. Copernicus was reluctant to see the work published and it was only after a visit from Georg Joachim Rheticus in 1539 that he released his manuscript. Rheticus was trained at Wittenberg, where Philipp Melanchthon dictated the approach to natural philosophy. Melanchthon wanted to understand God through the natural world to reveal a Creator and providential God and a model for social order too. Fallen man was surrounded by corruption, but the heavens were unaffected by the Fall. In cosmology, the observer could discover the will of God, especially since human beings, created in God’s image, still had traces of capacities for knowledge with which God had endowed Adam. The publication of Copernicus’s tract through the agency of a Wittenberg-trained Lutheran in Protestant Nuremberg was therefore not surprising. Even so, Copernicus’s text was issued with an anonymous preface, written by a Lutheran theologian, Andreas Osiander, which readers took to be by Copernicus himself. Concerned about its consequences for Aristotelian physics, Osiander emphasized that Copernicus’s astronomical system should not be taken as a representation of reality. On the contrary, it was just a mathematical way of seeing things. A reader who took it as offering a true account of the physical universe risked ‘departing from this discipline more foolish than he came to it’.

Copernicus’s text was a technical astronomical treatise. The specialists who read it followed Osiander’s advice. Only a handful accepted the physical truth of the Copernican theory before 1600, and only four came out in print in favour of it. Even the Danish astronomer Tycho Brahe rejected the triple motion of the earth (in 1587), proposing instead a compromise in which all the planets circled the sun, while it moved around a stationary earth. In Rome, those responsible for the Gregorian Calendar (adopted in 1582), a central plank of the Counter-Reformed Catholic Church’s claim to lead a global Christianity, used Copernicus’s calculations, but only because it made them more accurate.

The Dominican Giordano Bruno was the most notorious of those who made no secret of their Copernicanism. In Platonic-style dialogues he explored the possibility not only that the world revolved around the sun, but that the universe was infinite and that there was a plurality of inhabited worlds. Which particular heresy provoked his arrest in Venice in May 1592 is unclear, though in the hostile environment towards Neo-Platonism in Counter-Reformation Italy it was important to watch what one said. That explains why a professor of mathematics, appointed to a temporary post at the University of Pisa in 1589, Galileo Galilei, kept his Copernicanism initially to himself. In August 1597, however, he wrote a letter out of the blue to Johannes Kepler, whose book on the Cosmographic Mystery he had just read. It had delighted him, he said, because he himself had long been a Copernican. ‘With this hypothesis’ he had ‘been able to explain many natural phenomena which under the current hypothesis remain inexplicable’. He had even written a treatise in defence of Copernicanism, but could not conceive of publishing it while such views were held in derision.

Galileo’s natural phenomena emerged during his experimental programme investigating motion. Working with his sponsor, Guidobaldo dal Monte, the military brother of a cardinal and a marquis, Galileo proved to his satisfaction (using inked balls thrown across an inclined plane) that the path of a projected object was a symmetrical curve, a parabola or hyperbola. It looked like a chain, suspended between two points. For him, this answered one of the objections already foreseen by Copernicus to the physical possibility of the earth’s rotation: why was it that an object, dropped from a tower, fell in a straight line at its foot, and not to the west of it? The answer for Galileo was that, like his projectile or chain, it described a symmetrical curve. That was the beginning of Galileo’s perception of the relativity of movement, the possibility of motion being a uniform, dynamic force, capable of being explained mathematically. By the time of the letter to Kepler, Galileo had also developed another argument in favour of the earth’s movement about its axis, based on the movement of the tides. Galileo’s Copernicanism was that of a convinced anti-Aristotelian, attracted to its mathematical elegance and determined upon proving its reality.

In 1609, Galileo deployed his technical skills to produce a telescope. He made one which could magnify twenty times. Four years later, he manufactured tubes that magnified thirty times; by 1615, a hundred times. With such an instrument he had the potential to attract princely patronage as well as discover evidence in support of Copernicanism. That potential was realized when Galileo published The Starry Messenger (Sidereus Nuncius, 1610) in Florence. He dedicated the work to the duke of Tuscany, Cosimo II de’ Medici. That same year, Galileo moved to a well-paid post in Medici service. Galileo observed the four largest moons of Jupiter and used them as evidence of the physical reality of the heliocentric system. He christened them ‘the Medicean stars’ and set about persuading everyone of the reality of what he had seen. That was not so easy because the small number of high-powered telescopes which he had manufactured was already spoken for, and the instruments were not straightforward to use. But he had a two-pronged strategy for convincing those that mattered, notably in Rome. It involved convincing the experts and neutralizing the sceptics.

Initially things worked according to plan. The leading astronomer in the Jesuit College in Rome, Christopher Clavius, announced that he had seen the four moons rotating around Jupiter in November 1611. The ground was laid for Galileo’s triumphal visit to the papal city. Galileo announced supplementary discoveries: the phases of Venus, sunspots and the irregular face of the moon, all, as he hoped, confirming the Copernican hypothesis. The second prong of the strategy, however, was tougher. His opponents had inherited wisdom, orthodoxy and people in high places on their side. Even in Florence, there were those who harboured doubts, probably with reason, about his religious orthodoxy. The Inquisition began its inquiries, reporting in due course to Rome. When Galileo visited that city in 1615, he had to fight his corner in a curia dominated by a conservative pope who instructed Cardinal Bellarmine to issue a warning to Galileo to abandon the physical reality of Copernicanism. Galileo was not as good a courtier as his opponents, who held more cards. It was almost impossible to prove Copernicanism from astronomical observations, especially when there was a Tychonic alternative to hand. In his efforts to neutralize the supporters of that alternative, he antagonized the Jesuits, weakening his position. Galileo returned from Rome thinking that he could continue to argue for Copernicanism, albeit without prejudice to the Ptolemaic system.

Galileo’s optimism was misplaced. Initially, his prospects improved when the Florentine Maffeo Barberini was elected Pope Urban VIII in 1623. That encouraged him to carry on working on a treatise in which the arguments for and against heliocentrism were compared. The result, published in Italian in 1632 as Dialogo sopra i due massimi sistemi del mondo (Dialogue concerning the Two World Systems – the two systems in question being the Ptolemaic and the Copernican), was a masterpiece. It was imagined as an academic debate spread over four days between three colleagues. Two of them tossed arguments to and fro, but their persuasion was in only one direction: towards the reality of the heliocentric system. The third (‘Simplicio’) was the fall-guy, who kept feeding in old arguments which the others knocked down. Far from being ‘without prejudice’, Galileo’s Dialogue ridiculed his opponents, and Urban VIII thought it made fun of him too.

That was especially dangerous in the international politics of the year 1632. Urban had spent much of his career as the pope’s representative in France. He thought that country was the only guarantee against the power of Spain in Italy and Europe. But, in June 1630, Sweden, encouraged by France, entered the Thirty Years War and 1632 was the year of Swedish triumph. If France was the pope’s ally, then so were the Protestants. Urban did not want to fall out with the Florentine grand dukes but the latter were, by inclination, pro-Spanish. With his loyalties divided, Urban did not need the Galileo issue as a further matter of dispute. Galileo’s trial for heresy (1633) before the Roman Inquisition resulted in a suspended sentence. He was condemned to ‘abjure, curse and detest’ heliocentrism, sentenced to life imprisonment (commuted to house-arrest), and the Dialogue was placed on the Index.

Although Galileo was silenced, the Dialogue was translated and published in Latin north of the Alps through the offices of a French Protestant, Élie Diodati, who was a friend of Galileo’s. Galileo’s physics also circulated extensively and with it the vision of a universe dominated by mathematically abstracted ‘axioms’ which explained the real world. That was thanks to a Minim friar and mathematician in Paris, Marin Mersenne. He was an ‘intelligencer’ who put himself at the centre of a network of academics and antiquarians who treated natural philosophy as an alternative to the divisions in the world around. Virtuosi (the word came into vogue in the 1630s) had a constructive role. Stoic obedience to the powers that be might be the order of the day in politics, but in matters of natural philosophy, it was different.

Galileo’s Discourses and Mathematical Demonstrations Concerning Two New Sciences was published in Leiden in 1638 and translated into Latin by Mersenne the following year. It offered another dialogue between three people, only this time written in a style that imitated an open-ended discussion among its protagonists, each of them struggling to match the mathematical axioms proposed to the complexity of the real world. The subjects at issue ranged from the resistance of materials (the first ‘new science’) to motion (the second). But this second subject was interspersed with treatises on different sorts of motion. Galileo wanted to say that these were matters on which there was certainty: that motion was uniform, acceleration being distance travelled as the square of the time, and projectile motion being a symmetric curve. Galileo’s mechanics cemented his growing reputation. It was also a sign of the gathering respectability of the Copernican proposition and the emerging attractiveness of a mechanical picture of the universe.

Also in 1638, an English clergyman and virtuoso, John Wilkins, published The Man in the Moone, a pastiche of a work by Francis Godwin. It popularized Copernicanism while also inventing the genre of science fiction. Three years later, Wilkins plagiarized another of Godwin’s works in Mercury, or the Secret and Swift Messenger (1641), showing ‘how a man may with privacy and speed communicate his thoughts to a friend at any distance’. It was a treatise on the science of cryptography, signalling on land and sea, secret inks, mind-reading, and a prospectus for a ‘real character’ or scientific language. The possibilities for virtuosi remaining in contact with one another had never seemed greater, despite the forces of the Catholic Church. Aristotelianism was not dead, but the Aristotelian consensus was at an end. What would replace it remained opaque.

A MECHANICAL VISION

‘Mechanical’ in 1500 meant things that were practical and people who were manual. In the sixteenth century, however, the word acquired a different resonance: it described everything to do with machinery. That was partly because of the revival of the mechanics of Antiquity, particularly associated with Archimedes. But it was mainly because machines played a greater part in people’s lives. The machinery in question – astronomical and navigational instruments, compasses, surveying equipment, pumps and hydraulics, logarithmic devices, clocks and sundials, spectacles, maps, fortifications and guns – almost always required mathematical calculation for its manufacture and use, as well as proper training for its correct operation and maintenance.

Machinery also became a world view. Clocks, for example, were not particularly reliable time-keepers, but they were automata which stood as a model for God’s universe. In the new clock for Strasbourg cathedral, completed in 1574, the device stood in the south transept like a temple, 59 feet high. Fitted with a celestial globe, astrolabe and astronomical mechanisms as well as a terrestrial timepiece, it was designed to present the divisions of time from centuries to minutes. An angel turned a sandglass at each quarter hour, the four ages of life passed in front of Death during each hour, and at the last hour of each day, Christ appeared. Clockwork planetary models graced grandees’ curiosity cabinets. Juanelo Turriano spent twenty years designing a mammoth one for Charles V, to whom clocks were a passion. It was incomplete by the time of the emperor’s death, and was modified to take account of the calendar reform. In 1561, Eberhard Baldewein, clockmaker to Landgrave Wilhelm IV of Hesse-Kassel, produced an astronomical timepiece based on the latest planetary tables. Jost Bürgi, christened ‘a second Archimedes’ by Wilhelm, manufactured another in around 1604 for Emperor Rudolf II. Calibrated for the Gregorian calendar, it displayed the most important saints’ days and included two dials, one presenting a geocentric planetarium, and the other a heliocentric one. Kepler said that a later generation would rate Bürgi’s work as highly as Dürer’s paintings. On a clock presented to Duke Frederick III of Schleswig-Holstein in 1642, the figures of Copernicus and Tycho Brahe are engraved on the case. The legend under Tycho reads: ‘Quid si sic?’ (‘What if it be thus?’) and that under Copernicus: ‘Sic movetur mundus’ (‘Thus the world is moved’).

Mechanical objects were a component in Europe’s relations with the rest of the world and the drive for a global Christianity. Handsome clocks were commissioned from Augsburg manufacturers by the emperor to present to the Ottoman sultan as part of the annual tribute he owed from 1548. In a letter of 1552, Francis Xavier wrote that missionaries to Japan should have good scientific knowledge because the Japanese were fascinated by astronomical and geographical information: ‘They pester us with questions on the movements of the heavenly spheres, the eclipse of the sun, the waning and waxing of the moon, and the origins of water, snow, rain, hail, thunder, lightning and comets. Our explanations of these things have great influence, so that we win the souls of the people.’ The Jesuit Matteo Ricci, who was given permission to spend time in Chao-ch’ing, west of Canton, in 1583, captured the attention of Chinese scholars not merely by learning their language but through the scientific objects he brought with him. In 1584, he presented the governor with a copy of a map of the world, adjusted to Chinese sensibilities, and a sundial. In subsequent years, he presented spheres, globes and sundials to mandarins, prior to his teaching cosmography, mathematics and physics in Nanking and being invited to the imperial court at Beijing in 1605. The shape of the earth, the existence of the poles, the order and movement of the stars and planets and the use of globes were used as knowledge capital: ‘Through it,’ Ricci wrote, ‘many avowed . . . today that their eyes were opened to very significant things, to which they all previously had been blind.’

The mechanical analogy was commonplace by 1600. Comparing the confused contemporary politics at the beginning of the Thirty Years War with the stability of the heavens, the German Lutheran pastor Johannes Geyger wrote in Political Horology (1621): ‘how much wiser and ingenious must this Master be who . . . indeed has created by his omniscience the whole heavenly firmament and clockwork . . . ?’ ‘Surely the sky is the great Wheele of a Clocke,’ wrote the Huguenot scholar Philippe Duplessis-Mornay. ‘My goal,’ declared the astronomer Johannes Kepler, ‘is to show that the celestial machine is . . . like a clock.’

What began to change around the year 1600 was the degree to which mathematically derived axioms provided generalizations about the real world such that they could predict how it would always and everywhere behave. The behaviour of bodies in liquids, liquids in tubes, pendulums, levers under tension, projectiles, percussive hammers, strings, objects dropped from high places – the possibilities grew larger. In 1618, a young René Descartes joined the army of the prince of Orange, camped at Breda on the border with the Spanish Netherlands, to learn the art of war. While there, he met the local natural philosopher Isaac Beeckman. Together they tried to solve physical problems using mathematics. Like Galileo, whose work was as yet unpublished, they established a law for describing the fall of moving bodies. Beeckman’s ‘mathematico-physics’ inspired others as well, particularly from France. By the time Descartes returned to the Dutch Republic in 1628, he had defined his objective: how, on the basis of applying mathematics to physical problems, to use similar reasoning to explain everything known to the human mind?

He began writing down his notions (and dreams) in a notebook which Beeckman had perhaps given him. Probably thinking of joining Mauritz of Nassau’s army en route for Bohemia, Descartes recorded on 10 November 1619 – but the existing copy may be defective – that he had discovered the foundation of a ‘marvellous science’. His system was rooted in a metaphysic of human knowledge that supported his mathematical physics and his attempts to explain human behaviour. He believed that his method ensured certainty because it grounded natural knowledge on a few axioms whose certainty could be guaranteed by intuition, self-evidently true like proofs in geometry. Aristotelian distinctions of heaviness, lightness, hot and cold, wet and dry were banished. Nature was matter; and the essence of matter was extension, its only properties being the geometrically derived ones of shape, size, position and motion. His famous cogito ergo sum (‘I think, therefore I am’) was the dream-induced method by which Descartes hoped to establish that his intellect existed, and from which it was possible to proceed logically to prove the existence of God, the rules which he had established for the universe, the existence of matter and the solution to physical problems in the real world.

Elaborating the dream in the form of a treatise, which is what he published as the Discourse on Method (Discours de la Méthode, 1637), was easier than realizing it, for that meant studying the real world. In 1629, he told Mersenne: ‘I want to begin to study anatomy.’ A few months later, he wrote: ‘I am now studying chemistry and anatomy simultaneously; every day I learn something that I cannot find in any book.’ He undertook his own dissections, studied human and animal physiology, explored chemical medicine and geometry. Rather than being a fully fledged ‘method’, the Discourse became an introduction to three exemplifications (optics, meteorology and geometry) of a mechanist approach to the world, whose ramifications he would flesh out in publications over the next decade.

What Descartes offered was a model for a new world-system, constructed around the laws of motion and impact. His mechanical philosophy demanded a non-anthropomorphic universe and a willingness to consider God’s role in nature as that of a trustworthy clockmaker, at arm’s length from his creation. How the soul fitted in, and what connected it with the body, became a major critique of Descartes’s system. For it required a radical disjuncture between mind and body since material objects could no longer be seen as containing ‘sympathies’, ‘harmonies’ or ‘occult’ qualities, implanted in them by God. Ideas were not part of the universe. They were in our heads, and to be judged critically and rejected if reality contradicted them. The universe was an automaton: ‘There is a material world machine,’ he wrote, ‘or, to put it more forcefully, the world is composed like a machine of matter.’ His frequent references to ‘the machine of our body’ were intentional. ‘There are certainly no rules in Mechanics,’ he thought, ‘that do not also belong to Physics [i.e. physiology] of which it is a special case: it is no less natural for a clock composed of wheels to tell the time than for a tree grown out of a given seed to produce the corresponding fruit.’ His conviction that the laws of mechanics applied to the human body was reaffirmed after a discussion of the functioning of the heart, when William Harvey’s demonstration of the circulation of the blood provided him with an analogy of a pump for the human organ.

The eye was part of that machine. His dissections had revealed its physiology, his geometric skills explained its optics and his laws of physics determined the nature of light and colour. He could explain that it worked like a camera obscura. What we actually ‘saw’ in our brains bore no resemblance to the image that was focused onto the retina. Our brains received a decomposed signal which only our brain’s cognitive processes turned into ‘vision’. So Descartes’s mechanical vision short-circuited debates about the mismatch between vision and reality, and rendered irrelevant scepticism about what we could know. If we saw monsters, miracles, dreams and apparitions, they were the result of our own cognitive processes. They did not exist outside our heads. What we knew for sure was the world around us: its shape, size, extension and motion.

For Descartes’s contemporary Thomas Hobbes, the scientific study of optics was also a central preoccupation, and this ‘mechanical vision’ lay at the heart of his understanding of human society. He based his social philosophy on the primary concepts of movement and matter. Like Descartes, he drew on the discoveries of William Harvey, the circulation of the blood being a ‘vital motion’, the heart a ‘piece of machinery in which . . . one wheel gives motion to another’. The state was no longer a commonwealth with a soul. It was an ‘Artificiall Man’ with a heart, explicable as a mechanical device. The motions that caused apparitions in humans moved from the senses to the brain. The cognitive perception of them was received by the heart, from whence we had the notions of pain and pleasure that constituted the motive forces of human society. The Leviathan’s famous frontispiece of the ruler as a composite image of all his subjects was probably inspired by an optical device that Hobbes had seen in Paris in the 1640s. Jean-François Nicéron, a member of Mersenne’s circle, had designed a polygonal lens from which an image of Louis XIII was recomposed from bits of the portraits of fifteen Ottoman sultans. The state was a kaleidoscope of our own imagination. What held the political world together, like the natural world and the universe, were imposed laws. We had to make of them what we would.