‘On Subtlety’. It was over 900 pages in total - twice the length of the book it was reviewing - and it attacked Cardan vehemently for almost every aspect of the book. When Scaliger received no reply from Cardin he managed to convince himself that his efforts had caused his literary opponent to die of shame and decided to write him a glowing epitaph. According to the obituary, the late Cardan had been
gushed Scalinger. One can only imagine his horror when he found out Cardan was still alive and well and doubtless wondering why his opponant had so quickly changed his tune. This is just one of many entertaining anecdotes in the pages of
which I chuckled over as I read through it. Hence I will not be giving the author the Scaliger treatment, not least because it’s also one of the best narrative histories I have read in a long time.
God’s Philosophers begins with the famous quote by Issac Newton, that his achievements had only been possible because he was
‘standing on the shoulders of giants’ (in keeping with the tone of the book, we learn that it was actually
Bernard of Chartres who said this first in the 12th century). In contrast the Humanists of the ‘Renaissance’ era felt they were squatting on the shoulders of intellectual midgets; a menagerie of long winded medieval
‘logic choppers’ and
‘wordmongers’ who wrote in
‘barbaric’ Latin and had failed to properly understand the writings of the ancients. This scorn of their forebears began the longstanding myth that the Medieval period constituted an age of darkness and ignorance, a narrative which was adopted wholeheartedly in Enlightenment France and disseminated in the late 19th Century by the infamous
Andrew Dickson White. This impression of the Middle Ages remains alive and well today despite having been almost overwhelmingly discredited in the academic community. For example, leading historian of science
Edward Grant laments that ‘
the medieval period in Western Europe has been much underestimated and maligned, almost as if fate had chosen it as history’s scapegoat’. Another historian,
David Lindberg bemoans the fact that
‘the ignorance and degradation of the Middle Ages has become a kind of article of faith among the general public, achieving the status of invulnerability merely by virtue of endless repetition’. Hannam’s objective has been to reverse this trend by bringing the fruits of modern scholarship in the history of science to a wider audience and demonstrating that the natural philosophy of the Middle Ages contributed directly to the achievements of modern science.
In the popular imagination, the period from the fall of the Western Roman Empire in 500 to the arrival of the millennium in the year 1000 is a superb candidate for a Dark Age. Yet Hannam shows – by reference to the changes which took place in his home village of
Otham - that significant technological progress took place. Much of the classical heritage of Greece and Rome was cut off from Western Europe, but from the ruin of the Empire
there gradually arose a society sustained by improved agricultural techniques and powered by advances in machinery; the horse collar, three field crop rotation and the widespread use of water and tidal mills would ensure that Europe could support more people than ever before.

As intellectual culture was rekindled in the West on the wave of a population explosion and increased stability,
a great translation movement emerged which would bring the fruits of Classical learning to Europe through the works of Arab natural philosophers. Before this Medieval intellectuals, such as
William of Conches,
Adelard of Bath and
‘the mathematical Pope’,
Gerbert of Aurilliac, had to make do on scraps from the ill fated
Boethius and a few other authors. As the translated texts arrived from Spain and the Mediterranean, they were greedily absorbed into the medieval university; a type of legally autonomous corporation which could foster higher learning and carve out privileges from both secular rulers and the Church. The volatile and pugnacious
Peter Abelard had championed logic in his teaching; and, due to a series of calamities and quarrels, he ended up being nocturnally castrated, sentenced to perpetual silence and confined to a monastery. Upon his death, his ideas quickly dominated Christian scholarship. Natural philosophy would also gain an exalted status in the curriculum as the
‘handmaiden’ of theology; a guide to better preaching and a tool to combat the growing problem of heresy.
Yet the philosophy of the ancients was not straightforwardly compatible with the teachings of Christianity. Hannam is strong at outlining these issues and the subsequent efforts of
Albert the Great and the more famous
Thomas Aquinas to assimilate the new learning into a suitable framework. This came with the publication of the
Summa Theologiae which was
‘such a successful amalgamation of Aristotle’s philosophy with Christian doctrine that some Catholics have since failed to distinguish between the two’. Yet it was the conservative backlash represented by
the condemnations of 1277 which would delineate the boundaries between natural philosophy and theology and explore non Aristotelian physical and cosmological alternatives.

By this time, an international intelligentsia of scholars had emerged using the common language of Latin. They were able to enjoy considerable freedom under the cultural unity and political fragmentation of the period. This section of God’s Philosophers was perhaps the most enlightening, not least because so many of these figures remain undeservedly unknown or misunderstood. A chapter is devoted to demonstrating the syllabus of the medieval university through the life of
Richard of Wallingford, a figure who perfected the mechanical clock and ‘left a mechanical legacy without equal’.
Peter the Pilgrim became the first to realise that magnets have polarity (a critical insight for medieval navigation). Following in the footsteps of
Robert Grosseteste,
Friar Roger Bacon promulgated a strong rhetoric of experiment and provided a powerful synthesis of
optical theory. However, as Hannam shows, he has been mis-portrayed as a modern thinker. The principle motivation for his promotion of the sciences appears to have been his belief that the apocalypse was imminent and that the Jews and Arabs would have to be quickly converted to the true faith before the
anti-Christ and his minions showed up (one can compare this to the present day belief of
Richard Dawkins that the natural sciences must be used to convert everyone to atheism before the Christian fundamentalists and the Islamists bring on the apocalypse).
In the Fourteenth Century, a series of remarkable individuals emerged who would propel Medieval natural philosophy beyond the achievements of the ancients, combining mathematics and physics in ways that had not been achieved before. The setting for these scholars were the quadrangles of
Merton College.
Thomas Bradwardine, later Archbishop of Canterbury, tried to establish a formula to properly describe Aristotle’s laws of motion with the first use of a logarithm. Ultimately
Aristotle’s laws of motion were completely wrong, but Bradwardine had made an important step forward. Both he and the talented mathematician
Richard Swineshead adopted thought experiments and tried to think through the mathematics.
William Heytesbury is credited with the first use of
the mean speed theorem (though neither he nor his contemporaries had any idea of its immense significance).
Yet it would be Paris, not Oxford which would see
‘the apogee of Medieval Science’ as the ideas of
the Merton calculators crossed the channel. It was the rector of the University of Paris,
John Buridan, who rejected Aristotelian ideas concerning violent motion. In its place he formulated the concept of impetus and used it to describe how the planets keep moving in their orbits. He also came close to the modern principle of inertia. Perhaps inspired by Bradwardine, Buridan also compared the universe to a giant clock or
‘world machine’ which the creator had wound up, a forerunner of the later mechanical philosophy. One of the issues considered by Buridan was the possible rotation of the earth. This was an idea taken further by his pupil, the brilliant
Nicole Oresme who refuted most of the objections to a moving earth, but in the end went with the common sense approach contained in Aristotle and the Bible. His other major achievement was to prove the mean speed theorem in graphical form. This work would spread throughout Europe before
the Black Death swept in and decimated the intellectual culture of Europe.

The fifteenth century saw Europe begin to regain it’s poise and the arrival of
Nicholas of Cusa, a Cardinal who saw clearly the need for effective measurement in natural philosophy and whose cosmological speculations seem remarkably pertinent. It also saw the emergence of the humanist movement and their efforts to reintroduce ancient Greek into Europe; although as Hannam shows, they were also
‘incorrigible reactionaries’ seeking to
‘recapture an imaginary past’ who destroyed vast numbers of manuscripts and discarded many of the advances made in the Medieval period. Luckily the onset of printing ensured that the natural philosophy would reach the next generation of scholars, even as it was being systematically eliminated from the universities.
God’s Philosophers concludes with a broader sweep through the 16th century to show how
Copernicus,
Galileo and others used the achievements of the Middle Ages in their work. The term Renaissance after all, was coined partly to contrast the
‘rebirth’ of culture with medieval ‘stagnation’; although as Hannam points out, the Renaissance was
‘as much an age of faith as the Middle Ages and, if anything, more superstitious and violent’. Magical thinking became widespread and astrology and alchemy loomed large in the thought of figures like
Jerome Cardan,
John Dee and
Paracelsus, or to give his full name, Theophrastus Philippus Aureolus Bombastus von Hohenheim. In the case of Cardan, this led to an ill-advised attempt to draw up a horoscope of Christ. Their efforts led to advances in algeba, astronomy and new ideas of medicine which challenged the
Galenic tradition. Human dissection emerged in the Medieval period (Hannam shows the Church never banned it, in stark contrast to the taboos in effect in much of classical antiquity).
Vesalius attempted to perfect the work of Galen with his ‘On the Fabric of the Human Body’ but laid the groundwork for his overthrow. It would be
William Harvey who would demonstrate the circulation of the blood and seriously weaken the Galenic edifice. The reader of God’s philosophers may well, as I did, breathe a sigh of relief that things in medicine have moved on. Medical instruction manuals of the period advice doctors to always say that the patient is sick, since if he recovers ‘
you will be praised more for your skill’ and if he dies
‘his friends will testify that you had given him up’ (although with
NHS cut backs
on the way, perhaps this might be revived)
.
Elsewhere the towering figures of
Ptolemy and
Aristotle were being severely questioned. Both
Peurbach and
Regiomontanus had realised that Ptolomy’s astronomical system, with its complex geometry and clumsy equant had serious problems, yet it gave undeniably precise predictions. It would be the Polish clergyman
Nicholas Copernicus who would defy expert opinion and propose a heliocentric universe. His motivation for placing the sun at the centre of the universe may have sprung from occult theories about the sun, but his arguments for the rotation of the earth come straight from John Buridan and find their echoes in Nicholas of Cusa. Unsurprisingly, Copernicus was a product of the intellectual culture of the time, although he has so often been portrayed as a lone genius defying all that had gone before.
Another figure often depicted as marking a break from the past is
Galileo Galilei, yet as Hannam points out
‘Discourses on the New Sciences’ represents
‘the culmination of four centuries of work by medieval mathematicians and natural philosophers’. In his discussion of free fall, Galileo seems to be familiar with the work of the
Merton Calculators and reproduces the conclusions of
Oresme and
William of Heytesbury. His discussion of Projectile Motion builds on the conclusions of
Buridan,
Tartaglia and
Cardan. His observations on falling objects repeat those made a thousand years earlier by the Byzantine scholar
John Philoponus and more recently by
Simon Stevin. Galileo’s triumph was to produce an erudite synthesis of what had gone before and provide powerful experimental demonstrations. Similarly his contemporary
Johannes Kepler was able to build upon the European Medieval tradition and solve two of the greatest problems of the Middle Ages, the movement of the planets and the explanation of vision.
Modern science emerged as the triumph of three civilizations; Greek, Arab and Latin Christian, yet the last of these is so often left out of the narrative. God’s Philosophers restores the credit the medieval period deserves and has forced me to revise my belief that there was something which could justly be called a ‘scientific revolution’ in the Early Modern period. Hannam’s book persuasively argues for continuities and shows how the achievements of Keplar, Copernicus, Galileo and others were deeply rooted in the intellectual culture which had preceded them. The Middle Ages displayed none of the
‘general decay and degeneracy’ and
‘complete decadence of philosophy and the sciences' which
Condorcet and
Voltaire unjustly derided it for, rather it prepared the ground for the intellectual successes which would follow.