Leonardo da Vinci:Body as Machine and Machine as Body

Leonardo da Vinci.
Body as Machine and Machine as Body

The major obligation placed on a Renaissance artist was to exhibit a mastery of the human figure, providing vivid subjects for devotion and, in the case of narratives, knowing how to use gestures and expressions with due eloquence. The key properties were spirituality, beauty and decorum. An understanding of decorum was crucial for the painter, as Alberti had stressed in On Painting in 1435, since it involved the fittingness of form to function; that is to say every figure should be portrayed in a way that is appropriate to its character, social, station, sex and age, and to the emotion of the particular situation in which it finds itself. Leonardo recorded one heinous instance in which the rule was transgressed:
I recently saw an Annunciation in which the Angel looked as if he wished to chase Our Lady out of her room with movement of such violence that she might have been a hated enemy; and Our Lady seemed as if despair she was about to throw herself out of the window.
It is possible that Botticelli was the unnamed transgressor. The increasing numbers of secular subjects required of painters did not affect the basic stipulation of decorum, since the great heroes and villains of ancient myths and modern history all needed to be shown true to type.

Lorenzo Ghiberti, the sculptor of the gilded “Porta del Paradiso” on the Florentine Baptistery, had in his Commentaries stipulated that the painter should “know anatomy”, a prescription with which Alberti agreed. The dominant senior artists in Florence when Leonardo was learning his trade, Antonio Pollaiuolo and Andrea Verrocchio (Leonardo’s teacher) had become masters of bone, muscle and sinew, consciously emulating the renowned masters of classical antiquity. Whether any Renaissance artist in the generation before Leonardo and Michelangelo actually dissected is unclear. If Pollaiuolo’s knowledge was based on surface inspection alone, he must have conducted his studies with remarkable tenacity and visual penetration.

Observation and Received Wisdom
Leonardo has become renowned as a dissecting artist, probing, as legend tells us, the forbidden inner secrets of decaying corpses in the face of what he himself acknowledged as the repellent aspects of undertaking “an anatomy”. Supposedly, this was an illicit and sacrilegious activity, which placed him outside the realms of the Church. To be sure, late in his career in Papal Rome, one of his troublesome German technicians denounced his dissections to the Pope, but the drawn and written records of Leonardo’s anatomical investigations tell a different story. The one fully documented and comprehensive dissection of a complete human cadaver - probably the only one he conducted – was of a “centenarian” whose “sweet death” Leonardo witnessed in the Hospital of S, Maria Nuova in the winter of 1507-8.He focussed particularly on the “silting up” of the old man’s blood system, comparing the tortuous vessels of the old with the straight vessels of the young. (fig.1). Claiming to be 100 years old, the vecchio (“old man”, as Leonardo calls him on his pages of drawings) was presumably part of the system of consent, involving the Hospital, which allowed the artist to conduct an autopsy, followed no doubt by a proper burial. Such a procedure was more widely sanctioned than legend suggests. Leonardo certainly conducted other human dissections, but these seem to have been of particular parts or systems of the body. More often, he turned in the traditional way to animal material, which was not believed to differ significantly from human anatomy except in shape and dimensions. His greatest studies of the brain and the heart, the two key centres of human life, were based on organs from an ungulate, probably an ox. He also dissected at least one horse, probably in connection with his project for an equestrian monument in Sforza Milan. Unsurprisingly, in his efforts to master flight, he anatomised a bird’s wing, realising that its bone structure was analogous to the human arm and hand (fig.2). His known dissection of the foot of a bear seem to have been motivated by the unique opportunity that had presented itself.

1. The Superficial Vessels of the Left Arm with a Comparison between the Vessels of the Old and Young, Windsor, Royal Library, 19027.

2. Anatomy of a Bird’s Wing, a Bird in Flight and Studies of Proportion, Windsor, Royal Library, 12656.

Given Leonardo’s involvement with dissection and his repeated emphasis upon “experience” rather than book learning, it may seem surprising that his anatomical studies are so deeply permeated by traditional wisdom. The two-chamber system of the heart, to which he adhered for a long time, is a case in point. But we should remember that a dissected body, particularly in the era before preservatives, is a messy thing, which does not lucidly disclose its forms and functions to anyone who peers within. The anatomist needs to know how to dissect (which bits to cut and in what sequence) and how to make visual sense of the unfamiliar landscape of glutinous and collapsing forms. Seeing, as always, is a highly directed business. Additionally, for Leonardo, anatomy was not “descriptive” in the modern sense but was “functional”; in other words, he was always looked at form in terms of its function within the framework of natural law. If he was confident that he knew the function, he could reasonably suppose that the corresponding structure existed – like the item of plumbing that he inserted to connect the spinal chord to the penis in order to transmit the vital spirits into the sperm, in one of his early drawings.

The overarching framework was derived from ancient medicine. It comprised the four humours (corresponding to the qualities of pairs of the four elements) and the four temperaments: sanguine, phlegmatic, choleric and melancholic – what Leonardo called the “four universal conditions of man”. When he wrote to the Cathedral authorities about the need for “balance” in a healthy body, he was specifically referring to need for the balancing of the humours, so that one of them does not gain dangerous dominance. It was certainly not good to have an excess of melancholy. The dynamics of the living body were driven by fluids that conveyed the “spirits” – animal and vital – responsible for vivifying the body. Blood ebbed and flowed in the vessels (Harvey was long in the future), and the medulla in the hollow centre of the nerves pulsed with incoming information and outgoing messages. Leonardo did nothing to alter radically the physiology he had inherited, but he did develop an unprecedentedly integrated vision of the dynamism of the living body in three dimensions, in which the magic of his draftsmanship serves both as a mode of representation and as a form of research. Not infrequently, the act of drawing becomes an experiment in form and function, serving as the final validation and proof that he really could tell us how things worked.

The medical texts he knew, particularly Mondino de’ Luzzi’s Anatomy of the Human Body in 1316, which regularly served as a handbook for ritualised dissections in an anatomy theatre, provided basic descriptions and some rudimentary illustrations of the shape and location of the main organs, but there was nothing remotely like the compelling plastic visions Leonardo was to provide. His aspiration was not just to transform us into eyewitnesses of what could be seen in dissection but also to allow us to reach a true understanding of the marvellous forms and functions of the body in its whole and in its parts. To this end, he shows the components of the body not only in their sold form (often within the transparent outlines of the body), but also sectioned in various ways, drawn apart from each other in “exploded” diagrams, sometimes in see-through versions, and transformed into line diagrams explanatory of their actions. Every technique of anatomical illustration that was to be used in text-books up to the 19th century was precociously tested by Leonardo.