Was Leonardo a Christian?

‘Leonardo formed in his mind a conception so heretical as not to approach any religion whatsoever ... perhaps he esteemed being a philosopher much more than being a Christian.’

Vasari, 1560

In the account of Leonardo’s life in the first edition of Giorgio Vasari’s Lives of the Italian Artists (1550) this sentence follows a brief description of da Vinci’s enthusiasm for ‘le cose naturali’ – what nowadays we might call his scientific researches. Mysteriously Vasari omitted these words from the second edition of 1568, although he kept the rest of the passage. Many admirers of Leonardo (1452-1519) find the passage hard to swallow: could the artist responsible for some of the best known images of Christian art not have been a Christian himself? Could the same hand which so beautifully depicted the ‘Virgin of the Rocks’ and the ‘Virgin and  Child with Saint Anne’ have been a sceptic? Some have therefore maintained that the suggestion that Leonardo preferred to be a philosopher than a Christian (as was also said of his contemporary Machiavelli) must have been malicious gossip, which Vasari removed when he realized how false it was.

Even in his own day Leonardo was something of a mythical figure, a man of such genius that he could never be properly understood. Through the later sixteenth and seventeenth centuries this myth centred on his paintings. Only later did the generation of the Industrial Revolution discover in Leonardo a great mechanic and inventor as well as an experimental student of nature, who brought the artist’s keen eye to observe the little details of living things – including human anatomy – and the artist’s skill in exposition to describe what words could not.

Tall and handsome, a talented musician, a lover of fine horses, Leonardo evidently impressed all who knew him, even if they found his apparent indecision, and what they saw as a whimsical inability to finish so many projects, infuriating. The illegitimate son of a young lawyer Piero da Vinci, who took his family name from the little town from which they originated, and where they still held property, Leonardo was always something of an outsider. Leonardo’s mother Caterina is usually assumed to have been a peasant girl, who later married a local man who worked a lime kiln. He was still young when his father had married a suitable bride and took Leonardo to Florence. The marriage was childless, as was a second, after the first wife died young, which may have helped Piero to consider his firstborn a true member of his family, even a possible heir. Whether or not the young Leonardo’s potential as an artist was evident we cannot tell but he was apprenticed to Verrocchio, whose workshop was one of the leading art establishments of Florence. His apprentice years remain somewhat obscure; the earliest dated drawing, a landscape, was done when he was already twenty-one. Apart from formal entry into the appropriate guild, the event that has created most interest was a charge of homosexual misconduct. This was a capital offence but most of those accused were discharged after interrogation without any further proceeding or, if charged at all, found not guilty. No further action was taken in Leonardo’s case.

He left Florence in 1482 for Milan where he stayed for seventeen years. Ludovico Sforza, the younger son of the first Duke of Milan was effectively in charge, as a kind of regent and guardian for his nephew who had the title of duke but conveniently died young, so that Ludovico eventually had the title too.

Probably Leonardo had begun to interest himself in engineering and ‘le cose naturali’ while still in Florence, but it was at Ludovico’s court that his personality and his genius matured. There he painted his one great fresco, ‘The Last Supper’, as well as the most original of his Virgin and Child pictures. He began to study geometry, which was regarded as the greatest of the mathematical sciences; he tried to teach himself Latin; he began to collect a library, in the hope of mastering all the knowledge of the past, even if he always resented those who depended on what they had read in ancient books and despised artists as mere artisans. For Leonardo, keen observation, mathematical reasoning and testing everything by practical ex­perience outweighed all such scholarship.

A substantial body of mechanical invention on paper already existed by this time.  The idea that geometry is the key to understanding machinery – and, therefore, countless new inventions can be devised, and current machinery improved in performance – does not originate with Leonardo, but it did find in him by far its greatest exponent. More than that, he came to believe that if geometry is the key to mechanics, mechanics is the key to the whole of nature – including human nature. That is why he called mechanics ‘the paradise of the mathematical sciences’, so that an understanding of the mechanisms that enabled birds to fly might make it feasible to design a machine for flying. All he needed was to grasp the problem with his mind through sketches of real birds on the wing, and men need no longer be tied to the earth.

In recent generations, anatomy had become a subject with which artists were to have some acquaintance. But Leonardo now pursued his researches far beyond the call of duty. He wanted to understand how the human body worked, not just the bones and muscles, but nerves and heart and that mysterious, ominous, dangerous topic: the origin of human life in sex and the sublife of the foetus. He himself describes how unpleasant, how scary it was to cut up decaying bodies, flayed and dismembered, often at night, by candlelight which threw fearsome shadows all about.

He spent his most productive years in Milan, but this came to an abrupt end when Ludovico encouraged the king of France to invade Italy in pursuit of his claims to the  south of  the peninsula. It turned out badly for Ludovico himself who became the victim of  the French programme for expansion, was driven out, tried to return, was defeated and imprisoned in France for the rest of his life. Meanwhile Leonardo sought a new patron. Briefly he served Cesare Borgia, the Pope’s illegitimate son who was trying to carve out a principality for himself in the Romagna. Then he went home to Florence, where he was offered  a commission for a  secular painting much grander in scale than his Last Supper: a monumental fresco to cover one wall of the great chamber of the Palazzo Vecchio. It seems he completed only a central section, since covered over by Vasari. In Florence too he created his most famous painting, the Mona Lisa.

A grandiose scheme had been proposed by prominent figures in the Florentine government - notably Machiavelli - to divert the river Arno just above Pisa, so as to ruin the city which had taken advantage of the fall of Medicean rule to try to recover its independence. Leonardo took this idea much further, planning a major canal to link Florence directly with the lower reaches of the river, and then to the sea, because rapids on the Arno made it impossible to bring boats so far upstream. The task took him back into the Tuscan countryside and may have led him to profound and original thoughts on the geological history of his native landscape, and to attempts to map whole regions for ever-grander ideas of river diversion and canalization. This might have given him a deeper sense of the relation of valley to mountain and of land to sea, even imagining a distant era when much of Tuscany had been under the sea. For these speculations he could find an interpretation in the Meteorologia of Aristotle, a book he possessed. Likely enough, these walks in the mountains showed Leonardo the fossil shellfish he mentions, and once at least the traces of a larger vertebrate fish. In more than one draft he asserts that these cannot be the remains of creatures washed up by Noah’s Flood. Still less, he insists, could they have made their way so far and so high up in forty days. Surely they provided evidence that the whole region had been under the sea. Fascinated by the way hills, woods and rivers change their appearance in different lights and at varying distances, he had benefited from a journey into the high Alps, while he was in Milan.

He did not stay in Florence long. The French, now in command in Milan, invited him back and although the Florentine government wanted to ‘lend’ their great artist for a short term only, in the event he spent more time there. Once the French were expelled and a Sforza put back, Leonardo moved on again. For a while he was in Rome; he now had a Medici patron Giuliano, whose brother had become  Pope as Leo X.  Finally Leonardo left Italy altogether, as the attractions of France and the French king were too much. It seemed he might at last find a patron who truly appreciated  him, one richer and much more powerful than any Italian  princeling.

By this time he had won almost legendary status as sage as well as an innovative painter. Among the paintings he probably took with him to France was the Mona Lisa, and his only nude, ‘Leda and the Swan.’ ‘Leda’ has not survived. According to a story told a century later, Francis kept it in his ‘chambre de bain’….if so condensation would surely have ruined it. Still it was one of those pictures which attracted his pupils and followers so more than one near-contemporary copy survives, as well as the master’s own sketches. This picture has often been seen as a personification of nature and of the forces of natural life. Unlike Botticelli’s Venus, this Leda does not cover her nipples with one arm, or her sex with a lock of her very long hair. Her babies emerge from eggs like birds and look up with love at Leda as the mother who gave them life.

Does this picture suggest that Leonardo had moved away from early faith? Vasari says Leonardo derived his heretical ideas from his obsessive study of nature: ‘and so great were his whims that by philosophizing of nature, he applied himself to  understanding the properties of herbs, and to continual observation of the motions of the sky, the course of the moon and the comings and goings of the sun.’  This comment does not mention Leonardo’s investigation of human anatomy. Less organized than the anatomy of Vesalius, which was published more than twenty years after Leonardo’s death, he nevertheless delved deeper into the workings of the human body, as he tried to understand how it really worked. While he was back in Milan there were plans for a book to be written by a bright young teacher of medicine, Marc’Antonio della Torre, and illustrated by Leonardo. This fell through because Marc’Antonio died suddenly. To cut up and even to treat  the movements of the limbs quasi-mechanically: that was one thing – but the mind?

As Leonardo’s study of  perspective led to optics, and from the geometry of optics to the physiology of the eye, he could move on to all the organs of perception. Indeed this investigation may have informed some of his earliest anatomical studies at Ludovico’s court. One could easily be led on to consider how the impact of the outside world might be transmitted to the ‘common sense’ governed and interpreted by the soul. What then of a soul, without organs of sensation, with no ‘common sense’ area in its brain, since it has no brain? In several notes Leonardo explains why a spirit could not talk nor move of itself, except apparently upwards, and then it would melt into the air:

... there is no voice where there is no motion or percussion of the air there can be no percussion of the air: where there is no instrument; there can be no instrument without a body; and this being so, a spirit can have neither voice nor form nor strength... and if it  were to assume a body it could not penetrate nor enter where passages were closed…

Indeed, he argued, a spirit can hardly exist without a body, which would suggest that a spirit deprived of body and so of all organs of sight, hearing and so on could neither see nor hear. Here he speaks only of ‘spirito’ and perhaps only wished to dismiss as absurd popular belief in ghosts, just as he mocked the exaggerated and ridiculous claims of wizards and astrologers … and yet one note, on the ‘anima’, meaning perhaps ‘soul’ rather than spirit, ends:

the rest of the definition of the soul I leave to the minds of the  friars, fathers of the people, who by inspiration know all secrets … I leave aside holy writ for that is supreme truth.

Since elsewhere he jokes that ‘frati santi’ (holy friars) is an anagram of ‘farisei’, presumably meant to imply hypocrisy, he might have intended here to protect himself, to cover his back against the charge that he was denying the possibility of an immortal soul, whose existence would naturally re­quire it to oc­cupy a vacuum, a thing impossible in nature, as all agreed.

Optics could also inspire an interest in the great sources of light, sun and moon and stars. Despite Vasari’s assuring us of Leonardo’s continuous observation of the movements of celestial bodies, it was the subtle play of light and shade that most concerned him.

Yet this study of the movement of light convinced him that the moon and other planets shine only by reflected sunlight, as do the other planets.

Only the Sun is the great illuminator of the whole cosmos. Perhaps that is why he observes that the Earth is not the centre of the Sun’s orbit [its ‘cerchio’] nor at the centre of the universe, but merely in the centre of its companion elements, and bound up with them. Thus anyone standing on the Moon when it and the Sun are both beneath us would see this Earth and the element of water upon it just as we see the Moon and the Earth would light it as the Moon lights us.

In what seems to be a chapter heading in a planned universal compendium of knowledge, Leonardo proposed to demonstrate ‘how the Earth is a star’, so that ‘in your ­discourse you are to show that the Earth is a star and the glory of our world’. Therefore the Moon too must have four elements in layers one upon another just like on Earth. Perhaps the Moon’s markings encouraged him to see there evidence of seas and continents, as Galileo, aided by his telescope, was to do a century later.

If the Earth is a star and the Moon very like the Earth, that fundamental distinction between our Earth and celestial bodies breaks down, contrary to Aristotle and all accepted opinion. Only the Sun must be quite different. In one of his later manuscripts a passage is entitled ‘Praise of the Sun’. This is cosmology or natural philosophy rather than astro­nomy – profound imaginative thought rather than careful observation. The Sun’s light, he maintains, gives light to all the planets, perhaps to all the other stars as well, and all living things derive from it: there is ‘nowhere to be seen a body of greater magnitude and power [‘virtú’] since ‘there is no other light nor heat in the world’ (as he promises to show us in his great book of all nature). Besides, ‘I could wish I had words to use to condemn those who want to praise, and adore men more than such a Sun’. Then he declares that’ those who have chosen to worship men as gods, as Jove, Saturn, Mars and the like, have fallen into very grave error, seeing that even if a man were as big as our earth, he would look no bigger than the least of stars which appears as but a speck in the universe; seeing moreover that these are mortal men, rotting and corruptible in their tombs’. Now he may speak here of the ancient Greco-Roman gods – but was he protecting himself by this example? Although the ancient gods were human in appearance they were not regarded as human in their true nature by the ancients who revered them. Yet perhaps he meant a man who was revered as a god in his own time.

In a final comment to this Praise of the Sun he adds ‘the Sphere and Marullus praise the Sun, with many others’. The ‘Sphere’ would be a handbook of contemporary astronomy, probably that of Joannes de Sacrobosco (John of Holywood?). Marullus was a very different character, not an astronomer at all. Michael Marullus Tarcaniota styled himself ‘of Constantinople’, as he claimed that his mother was pregnant when the family fled the city before the advancing Turks, who captured it in 1453. Marullus and Leonardo were almost exact contemporaries. Al­though he knew Greek and considered himself a Greek, Marullus grew up in Dubrovnik, then a more or less Italian town known as Ragusa, where he must have learnt Latin at school. He followed the career of a professional soldier – one who nevertheless wrote poetry in Latin. While Leonardo was in Milan, Marullus brought out his Hymni Naturales in 1497. These were hymns to Nature rather than ‘natural hymns’. In them he addresses hymns of praise after the model of Homer to the gods of the ancient world, calling up an ancient Greece of the imagination, whose memory and heritage he was determined to save. In reality he is not singing the praises of the all-too-human gods of Olympus; his gods are personifications of a Platonic world, a natural world. Among them are hymns to Earth and to the Sun, whose echoes we can hear in Leonardo’s words. Some of the Greek exiles turned again to the great days of a glorious Antiquity; and that could include its religion, although in an abstract version. Among a few of the more radical thinkers of the time there was also a renewed interest in the ‘Oration to the Sun’ of Julian, called ‘the Apostate’, the last Roman emperor to try and stem the incoming tide of Christianity. Marullus however was the only one to put new quasi-religious philosophy of nature into rotund Latin, as if he sought to be a new Lucretius. For Lucretius nature operates on simple rules without need of divine intervention to explain it or to account for our misfortunes. His poem De Rerum Natura (On the Nature of Things) was found in Marullus’ knapsack after he drowned attempting to ford the river Cecina while serving with the army of the lord of Piombino against Cesare Borgia.

For many, no doubt, this curious mystique of the Sun, like other supposedly neo-pagan ideas was more of a literary pose. Others, like Marullus, did take it seriously – and perhaps Leonardo did too. At all events his grand vision of the Sun as a virtual deity does not come from astronomical observations.

Are there other writings which might elucidate Leonardo’s religious views? One potential source would be his profetie – literally, prophecies. Although written in the future tense these are not prophecies but short sayings, in the form of riddles, which point out the paradoxes of our life. None are illustrated and perhaps that is why they have attracted relatively little interest among all Leonardo’s works. Nicholl, in his biography (2004) mentions a few as throwing light on Leonardo’s dream world; others, with some of Leonardo’s fables, he thinks ‘also express an idea of nature as the wounded, exploited victim of man’s rapacity’. The imagery of both is often violent, painful and all too often creatures, even plants, suffer for their pride or their simplicity, or at times their own generosity. Vasari tells us how he felt for the whole of nature, how he bought caged birds to set them free, became a vegetarian (one of the first in modern Europe) out of sympathy for all living creatures rather than asceticism. One Italian contemporary compared him to the Guzzati, that is, Gujarati, presumably meaning the Jains, who astonished European travellers with their refraining from all meat and their institution of animal hospitals. The profetie were probably composed after the French invasion of 1494, during a time when foreign armies marched across Italy, and when the fragile peace of decades was revealed as precarious.

The term prophecy apparently meant that these were to be proclaimed in a fantastic manner as though he were crazy, yet a mask of madness might be used to offer safe cover for outrageous and dangerous opinions. Several do have a distinctly religious character. Of these some might indicate a pre-Protestant outlook, a few decades before Luther and Calvin. They betray hostility to the clergy, secular or religious. So, of the friars’ confessors: ‘unhappy women will of their own free will reveal to men all their sins and most shameful and secret deeds’. Or, speaking of churches and the dwellings of friars: ‘many there will be who will give up work and labour and poverty of life and goods and will go to live in splendid buildings, declaring that this is the way to make themselves acceptable to God’. Elsewhere, he speaks of friars who ‘spend only words and receive great riches and grant paradise’ and of ‘the religion of friars who live by their saints who have been dead for a long time’. This smacks of the Tuscan anti-­clericalism, directed particularly against the friars, that was in some circles a commonplace that went back to Boccaccio, if not before.

In themselves these wry comments hardly make Leonardo a scientific atheist. Still, when Leonardo includes a prophecy about worshipping the pictures of saints, he explains that

men will speak to men who hear not; having their eyes open they will not see; they will speak to them, but will not be answered; they will implore favours of those who have ears but hear not: they will make light for the blind.

This last phrase may well refer to the lighting of candles in churches before the images of saints. This does recall the protests against idol worship often repeated in the Old Testament and taken up by radical Reformers.

What of priests in general? Priests who say Mass are men who

when they go to work will put on the richest clothes … after the fashion of aprons ... an infinite number of men will sell publicly and unhindered things of the very highest price with­out leave from the master of them.

That sounds like the Protestant denunciation of indulgences. Sharper still is his ‘prophecy’ on Christians in general: ‘Many who hold the faith of the son only build temples in the name of the mother’, and later he says of the grief for the crucified Christ on Good Friday, ‘in all parts of Europe there will be a lamentation of great peoples for the death of a single man who died in the east … un solo omo morto’! Surely that suggests that this was the man worshipped as a god whom he really means when he objects to the worship of men as gods in that cosmological discourse on the wonders of the Sun.

In another note, perhaps also quite late in his life, he urged that only genuinely virtuous people should be honoured,

for these are your gods on earth, these deserve from you statues, images and honours; but I do remind you that their images are not to be eaten by you as is done in some regions of India, for when their images perform some miracle – according to them – the priests cut them in pieces, as they are wooden, and give the pieces to the folk of the country, but not without a price. The each one grates his portion very fine and they put it on the first food that they eat. So through their faith they hold that they have eaten their saint, and believe that this will guard them against every danger. What then do you think of your species, man? Are you as wise as you think yourself? Are these things to be done by men?

Much effort has been expended on trying to find some Indian cult to which this custom might be attached, in the Old World or the New, but without success. Perhaps it is instead a cryptic hint at the Real Presence in the Mass, given the disdain he has expressed in the ‘prophecies’ for those who claim to carry the Body of God, the Corpus Domini, in their stomachs, almost as if he were a Protestant just before the Reformation.

Vasari also tells us that Leonardo acknowledged some difficulty in portraying Jesus in the ‘Last Supper, because he felt nobody could really show that ‘celestial divinity’. To the modern viewer of the ‘Last Supper’ Leonardo’s Jesus is essentially human: tragic, heroic, the Man of Sorrows saddened at the treachery of one disciple and the feebleness of the others, but is he divine? The scene shows rather all the variations of shock, dismay, fear, even incredulity on the faces of Jesus’ followers – almost as a brilliant exercise in the manifestation of these diverse emotions. In another notebook there is a strange line in which Leonardo seems to say that ‘when I made the Lord God a child, you put me in prison, now if I make him grown up, you will treat me worse’. Since no document ever mentions that Leonardo was imprisoned for some heretical painting, this is not easy to understand. Perhaps he is referring to some drawings, in which the Christ Child is playing with a cat while seated on his mother’s lap. That might have been seen as unorthodox; playing with a lamb was sound theology, as was a goldfinch, (which appears in another Leonardo Madonna); cats, however, were regarded by some with suspicion, more likely to be the familiars of witches than of the Holy Family, or make Jesus look too much like an ordinary toddler, and unsuited to go above an altar.   

However, much of the traditional world-picture Leonardo may have abandoned or at least questioned in his unceasing search for reality, it is hard to see him as a mechanist or atheist philosopher. For Vasili Zubov, writing in Khrush­chev’s USSR, Leonardo believed in nature alone and God is just a convenient and safe term for Nature, as for Spinoza after him or Aristotle nearly two millennia before. All the same Martin Kemp (1981) is not alone in regarding Leonardo’s appeals to the Creator as genuine expressions of a heartfelt religious awe at the wonder of the world – which would be quite consistent with his theological doubts – and his resolve to seek a true understanding of the works of nature and the works of man. Perhaps we should consider him best as a theist who insists on the respect we owe our Creator and on the reverence due to Him, who admires Jesus the man, but can not identify him with that creator God ... in short, as an early unitarian.