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Natural Science - Year I

Unit 22: Leonoardo da Vinci and Anatomy

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History Weblecture for Unit 22

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History Lecture for Unit 22: Leonardo and Human Anatomy

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Lecture outline:

The Beginning of Modern Anatomy

We now begin a study of the scientific achievements of the European Renaissance, an intellectual "awakening" that began in Italy around the fourteenth century and lasted until the seventeenth century. The period is characterized by changes in artistic representation of both people and nature, voyages of exploration which led to the discover of the American continents and sea routes to India and China, and great changes in religious and political institutions. All of these affected the way Europeans viewed the world, and ultimately led to the overthrow of the Aristotelian world view--the Scientific Revolution. We'll approach the new world view from two directions: changes theories of human anatomy, and changes to the celestial order, culminating in a new concept of the world as a machine, predictably obeying laws of nature at every level.

Medicine in 1400

By the end of the thirteenth century, Europe had recovered many of the Greek works in philosophy and history, often through the medium of Arab commentaries. The great universities of Italy, which became the centers of medical studies, taught the theories of Galen and his Arab successor, Avicenna.

Read the introduction by ibn Sina (Avicenna) to his encyclopedic work On Medicine at Fordham's Medieval Sourcebook site (this is a great collection of English and Latin texts of medieval works).

[1 page.]

  • How is knowledge acquired?
  • How does ibn Sina apply Aristotle's concepts of the four types of causality to the operation of the human body, and its health and illness?

Following Avicenna, medical practice in the late middle ages in the Latin West rested on the identification of the four terrestrial forms of matter--earth, fire, water, and air--with four bodily humors: black bile, blood, phlegm, and yellow bile. Every human was a combination of these four elements. A healthy person had the four in balance; an unhealthy person could have an excess of one or a lack of another. For example, a person with a fever had an excess of the blood humor, so the way to treat fever was to bleed the person, taking perhaps a pint of blood by cutting through a vein in the arm. Obviously, this often left a person too weak to combat the real source of the disease or even led to new infections, but the practice of bleeding for fevers was so well established in medical circles that it lasted into the nineteenth century.

In the middle ages and through the Renaissance, there were no state-run hospitals or public physicians. If you were not a nobleman, you made do with home remedies made from herbs, which might or might not work, or if you were very lucky, you went to one of the hospitals run by a monastic order. The nobility, however, retained personal physicians to attend their households, and these doctors were trained in the universities. The most famous medical universities were at Bologna and Padua in Italy--and it was to the latter that Andreas Vesalius and Nicolai Copernicus went in search of the latest medical theories and training.

Art, Exploration, and Printing

Several factors contributed to the new theories men like Vesalius and Copernicus proposed. These included the new art of perspective, the new knowledge of different plants and animals brought back by the exploration of the Americas, and the invention of printing.

In Italy, the painters and architects of the fourteenth and fifteenth centuries moved away from the symbolic art of the middle ages (where size and position were used to show spiritual importance rather than actual physical location) to representative art, which depicted people, plants, buildings with attention to how they actually appeared. In particular, they developed techniques of perspective that could accurately show the size of objects and distance between them. This change in graphical representation had a serious and important impact on science: the practice of including accurate drawing in books made it possible to share detailed information in a way that had not been previously possible.


The subject matter for such drawings expanded as Europeans ventured further along the coast of Africa and around that continent to India and China, or crossed the Atlantic to the New World. The Americas in particular offered many new plants and animals, most of which we take for granted. Much of your Thanksgiving dinner--corn, tomatoes, bell peppers, yams, potatoes, and turkey--were unknown to the people of Europe and Asia before 1500. Like Dioscordes before them, the naturalists of the fifteenth and sixteenth centuries cataloged these new plants and animals and tried to discover their useful or dangerous properties. They thought that tomatoes, which have similarities to the deadly nightshade they already knew, were poisonous, but tobacco appeared to be an interesting cure for certain kinds of lassitude. They also learned the benefits of drinking tea (which comes from East Asia, not America), and found that South America provided a new source of the strange beans the Arabs called quaveh (coffee) and a wonderful new bean, the cacao, from which we now make chocolate.

The spread of herbal information (among other things) was greatly aided by Johannes Gutenberg's invention of the printing press, which combined the Chinese idea of movable type with a rapid method of inking type and impressing paper. Gutenberg's first publication was a Latin version of the Bible, which became available in 1453. His publication coincided with the fall of the great capital of Byzantium, Constantinople, to the Turks. The Christian citizens of Constantinople, who had many trade ties with Italy and the cities of southern Germany, fled Constantinople for Western Europe, bringing with them their manuscripts. Within a decade, most European cities could boast several printers able to convert these handwritten copies of the works of the church fathers, the Greek philosophers, and the Arab commentators into printed copies—along with political propaganda, advertisements, and books of astrological forecasts. But the works of the naturalists also found their way into publication, and their drawings were published as well (see the woodcuts and engravings of Albrecht Durer, for example).

Leonardo da Vinci

One of the greatest thinkers, painters and inventors of this period is the Italian Leonardo da Vinci. Leonardo was born in Florence in 1452, and studied painting with the masters in Florence, becoming a member of the guild in his early twenties. He experimented throughout his life with many painting styles and techniques, including chiaroscuro (contrasts of light and dark), frescoes (painting on a damp wall instead of canvas), and the more traditional canvas oil paints. He often started a work of art in order master a particular technique, and left the painting or sculpture unfinished (to the despair of his fans and patrons) when he was satisfied that he had learned what he could from the project. His most famous (completed) paintings include the Adoration of the Magi, the Last Supper (a fresco), and the Mona Lisa, an oil painting.

Leonardo regarded painting as a superior way of presenting information. He says in his books on the practice of painting:

If you condemn painting, which is the only imitator of all visible works of nature, you will certainly despise a subtle invention which brings philosophy and subtle speculation to the consideration of the nature of all forms — seas and plains, trees, animals, plants and flowers — which are surrounded by shade and light. And this is true knowledge and the legitimate issue of nature; for painting is born of nature — or, to speak more correctly, we will say it is the grandchild of nature; for all visible things are produced by nature, and these her children have given birth to painting. Hence we may justly call it the grandchild of nature and related to God.

In his notebooks, the drawings are always the most important component, and any text he includes is there to explain the drawings, not the other way around. He tried to develop a "science of painting", and he proposed a project to observe all the objects in the visible world and create an encyclopedia of paintings and drawings which would capture these objects exactly. Like many of his other projects, this one was never carried out.

Leonardo's conviction that pictorial art was the most accurate way to depict an object led him study many kinds of things, both natural and man-made. His observations of birds led to the invention of some flying machines; modern model reconstructions based on his drawings work, but we don't know whether Leonardo ever built any of them. His convictions also led him to study the human body more closely than any of his artistic (and many of his medical) predecessors. Despite the Catholic prohibitions and the general cultural sentiment against dissection, Leonard managed to dissect at least thirty corpses, and his notebooks contain many carefully-made drawings of skeletons, muscle structures, and organs like the heart and lungs. The level of detail in Leonardo's work from was not duplicated until 1543, when Vesalius published the first anatomy book with woodcuts based on careful dissections.

Despite his tremendous achievements, Leonardo's influence was limited in his lifetime to his public paintings, and in the generation after he died, to those few sections of his notebooks which his friends managed to assemble for publication. He was secretive about many of his studies, and wrote the annotations to his drawings in reverse writing—easily decipherable with a mirror, but still able to slow down any conversion to a printed form. Most of his notebooks remained out of circulation, and many of them were rediscovered only in the last century or so. His work in human anatomy, in particular, had to be repeated.

Study the drawings Leonardo made of a human hand and a human arm. You can look at more anatomical drawings of Leonardo da Vinci or find any of his drawings of the human body from another source (Encyclopaedia, etc).

[1 page.]

  • What kinds of details does Leonardo show in his drawing?
  • Why do you think he separates parts occasionally, and shows them in isolation, as well as together?
  • How does he use text to link captions to parts of the drawing? This is similar to medieval geometry diagrams, but new to anatomical drawings. Notice how he uses letters to tie comments to specific locations in his drawing.
  • Look at the "backwards" handwriting.

Leonardo wasn't alone in his studies of the human body as a precursor to producing art reflecting the body in its the correct proportions.

Take a quick look at this woodcut of a hand by Albrech Dürer, probably drawn around 1528. Dürer's work was highly influential, since it was widely published in the late sixteenth century.

[1 page.]

  • How important is actual measurement to the artist in this woodcut?
  • How does the level of detail of the features of the hand compare to Leonardo's drawings?
  • Some of the differences will be due to the limitations of a woodcut compared to a pencil sketch. How does the availability of a reproduction process affect what can and can't be communicated with pictures?
  • If Leonardo's drawings were unavailable to others for four centuries, is what he accomplished "science"? (This is another way to ask: can we do science as individuals, or must science be done in community?)

Study/Discussion Questions:

Further Study/On Your Own