Fritjof Capra (2 page)

PREFACE

Leonardo da Vinci, perhaps the greatest master painter and genius of the Renaissance, has been the subject of hundreds of scholarly and popular books. His enormous oeuvre, said to include over 100,000 drawings and over 6,000 pages of notes, and the extreme diversity of his interests have attracted countless scholars from a wide range of academic and artistic disciplines.

However, there are surprisingly few books about Leonardo’s science, even though he left voluminous notebooks full of detailed descriptions of his experiments, magnificent drawings, and long analyses of his findings. Moreover, most authors who have discussed Leonardo’s scientific work have looked at it through Newtonian lenses, and I believe this has often prevented them from understanding its essential nature.

Leonardo intended to eventually present the results of his scientific research as a coherent, integrated body of knowledge. He never managed to do so, because throughout his life he always felt more compelled to expand, refine, and document his investigations than to organize them in a systematic way. Hence, in the centuries since his death, scholars studying his celebrated Notebooks have tended to see them as disorganized and chaotic. In Leonardo’s mind, however, his science was not disorganized at all. It gave him a coherent, unifying picture of natural phenomena—but a picture that is radically different from that of Galileo, Descartes, and Newton.

Only now, five centuries later, as the limits of Newtonian science are becoming all too apparent and the mechanistic Cartesian worldview is giving way to a holistic and ecological view not unlike Leonardo’s, can we begin to appreciate the full power of his science and its great relevance for our modern era.

My intent is to present a coherent account of the scientific method and achievements of the great genius of the Renaissance and evaluate them from the perspective of today’s scientific thought. Studying Leonardo from this perspective will not only allow us to recognize his science as a solid body of knowledge. It will also show why it cannot be understood without his art, nor his art without the science.

As a scientist and author, I depart in this book from my usual work. At the same time, however, it has been a deeply satisfying book to write, as I have been fascinated by Leonardo da Vinci’s scientific work for over three decades. When I began my career as a writer in the early 1970s, my plan was to write a popular book about particle physics. I completed the first three chapters of the manuscript, then abandoned the project to write
The Tao of Physics
, into which I incorporated most of the material from the early manuscript. My original manuscript began with a brief history of modern Western science, and opened with the beautiful statement by Leonardo da Vinci on the empirical basis of science that now serves as the epigraph for this book.

Since paying tribute to Leonardo as the first modern scientist (long before Galileo, Bacon, and Newton) in my early manuscript, I have retained my fascination with his scientific work, and over the years have referred to it several times in my writings, without, however, studying his extensive Notebooks in any detail. The impetus to do so came in the mid-1990s, when I saw a large exhibition of Leonardo’s drawings at The Queen’s Gallery at Buckingham Palace in London. As I gazed at those magnificent drawings juxtaposing, often on the same page, architecture and human anatomy, turbulent water and turbulent air, water vortices, the flow of human hair and the growth patterns of grasses, I realized that Leonardo’s systematic studies of living and nonliving forms amounted to a science of quality and wholeness that was fundamentally different from the mechanistic science of Galileo and Newton. At the core of his investigations, it seemed to me, was a persistent exploration of patterns, interconnecting phenomena from a vast range of fields.

Having explored the modern counterparts to Leonardo’s approach, known today as complexity theory and systems theory, in several of my previous books, I felt that it was time for me to study Leonardo’s Notebooks in earnest and evaluate his scientific thought from the perspective of the most recent advances in modern science.

Although Leonardo left us, in the words of the eminent Renaissance scholar Kenneth Clark, “one of the most voluminous and complete records of a mind at work that has come down to us,” his Notebooks give us hardly any clues to the author’s character and personality.
¹
Leonardo, in his paintings as well as in his life, seemed to cultivate a certain sense of mystery. Because of this aura of mystery and because of his extraordinary talents, Leonardo da Vinci became a legendary figure even during his lifetime, and his legend has been amplified in different variations in the centuries after his death.

Throughout history, he personified the age of the Renaissance, yet each era “reinvented” Leonardo according to the zeitgeist of the time. To quote Kenneth Clark again, “Leonardo is the Hamlet of art history whom each of us must recreate for himself.”
²
It is therefore inevitable that in the following pages I have also had to reinvent Leonardo. The image that emerges from my account is, in contemporary scientific terms, one of Leonardo as a systemic thinker, ecologist, and complexity theorist; a scientist and artist with a deep reverence for all life, and as a man with a strong desire to work for the benefit of humanity.

The powerful intuition I had in that London exhibit, that the Leonardo I describe above is indeed “the Leonardo of our time,” was confirmed by my subsequent research and exploration of the Notebooks. As art historian Martin Kemp wrote in the catalog of an earlier exhibit of Leonardo’s drawings in the Hayward Gallery in London:

It seems to me that there is a core to [Leonardo’s] achievement, however imperfectly transmitted and received by different generations, that remains intuitively accessible. What has been sensed is that his artistic productions are more than art—that they are part of a vision embracing a profound sense of the interrelatedness of things. The full complexity of life in the context of the world is somehow implied when he characterises any of its constituent parts…. I believe that his vision of the totality of the world as a kind of single organism does speak to us with particular relevance today, now that our technological potential has become so awesome.
³

Kemp’s portrait of the Leonardo of that exhibit, characterized so eloquently in the passage above, mirrors my own. It is this Leonardo who will emerge from my exploration of his unique synthesis of science and art.

Fritjof Capra
Berkeley, December 2006

Figure P-1: Leonardo’s Self-Portrait, c. 1512, Biblioteca Reale, Turin

INTRODUCTION

An Interpreter of Nature

I
n Western intellectual history, the Renaissance—a period stretching from the beginning of the fifteenth to the end of the sixteenth century—marks the period of transition from the Middle Ages to the modern world. In the 1460s, when the young Leonardo da Vinci received his training as painter, sculptor, and engineer in Florence, the worldview of his contemporaries was still entangled in medieval thinking. Science in the modern sense, as a systematic empirical method for gaining knowledge about the natural world, did not exist. Knowledge about natural phenomena, some accurate and some inaccurate, had been handed down by Aristotle and other philosophers of antiquity, and was fused with Christian doctrine by the Scholastic theologians who presented it as the officially authorized creed. The authorities condemned scientific experiments as subversive, seeing any attack on Aristotle’s science as an attack on the Church.

Leonardo da Vinci broke with this tradition. One hundred years before Galileo and Bacon, he single-handedly developed a new empirical approach to science, involving the systematic observation of nature, logical reasoning, and some mathematical formulations—the main characteristics of what is known today as the scientific method. He fully realized that he was breaking new ground. He humbly called himself
omo sanza lettere
(“an unlettered man”), but with some irony and with pride in his new method, seeing himself as an “interpreter between nature and humans.” Wherever he turned there were new discoveries to be made, and his scientific creativity, combining passionate intellectual curiosity with great patience and experimental ingenuity, was the main driving force throughout his life.

For forty years, Leonardo collected his thoughts and observations in his celebrated Notebooks, together with descriptions of hundreds of experiments, drafts of letters, architectural and technological designs, and reminders to himself about future research and writing. Almost every page in these Notebooks is crowded with text and magnificent drawings. It is believed that the entire collection ran to 13,000 pages when Leonardo died without having sorted them, as he had intended. Over the subsequent centuries almost half of the original collection was lost, but over 6,000 pages have been preserved and translated from the original Italian. These manuscripts are now widely dispersed among libraries, museums, and private collections, some in large compilations known as codices, others as torn pages and isolated folios, and a few still as notebooks in their original bound forms.
¹

THE SCIENCE OF PAINTING

Leonardo was gifted with exceptional powers of observation and visual memory. He was able to draw the complex swirls of turbulent water or the swift movements of a bird with a precision that would not be reached again until the invention of serial photography. He was well aware of the extraordinary talent he possessed. In fact, he considered the eye as his principal instrument as both a painter and a scientist. “The eye, which is said to be the window of the soul,” he wrote, “is the principal means whereby sensory awareness can most abundantly and magnificently contemplate the infinite works of nature.”
²

Leonardo’s approach to scientific knowledge was visual. It was the approach of a painter. “Painting,” he declares, “embraces within itself all the forms of nature.”
³
This statement, in fact, is the key to understanding Leonardo’s science. He asserts repeatedly, especially in his early manuscripts, that painting involves the study of natural forms, and he emphasizes the intimate connection between the artistic representation of those forms and the intellectual understanding of their intrinsic nature and underlying principles. For example, in the collection of his notes on painting, known as
Trattato della pittura (Treatise on Painting)
, he writes:

The science of painting extends to all the colors of the surfaces of bodies, and to the shapes of the bodies enclosed by those surfaces…. [Painting] with philosophic and subtle speculation considers all the qualities of forms…. Truly this is science, the legitimate daughter of nature, because painting is born of nature.
⁴

For Leonardo, painting is both an art and a science—a science of natural forms, of qualities, quite different from the mechanistic science that would emerge two hundred years later. Leonardo’s forms are living forms, continually shaped and transformed by underlying processes. Throughout his life he studied, drew, and painted the rocks and sediments of the earth, shaped by water; the growth of plants, shaped by their metabolism; and the anatomy of the animal (and human) body in motion.

THE NATURE OF LIFE

Nature as a whole was alive for Leonardo. He saw the patterns and processes in the microcosm as being similar to those in the macrocosm. He frequently drew analogies between human anatomy and the structure of the Earth, as in the following beautiful passage from the Codex Leicester:

We may say that the Earth has a vital force of growth, and that its flesh is the soil; its bones are the successive strata of the rocks which form the mountains; its cartilage is the porous rock, its blood the veins of the waters. The lake of blood that lies around the heart is the ocean. Its breathing is the increase and decrease of the blood in the pulses, just as in the Earth it is the ebb and flow of the sea.
⁵

While the analogy between microcosm and macrocosm goes back to Plato and was well known throughout the Middle Ages and the Renaissance, Leonardo disentangled it from its original mythical context and treated it strictly as a scientific theory. Today we know that some of the analogies in the passage quoted above are flawed, and in fact Leonardo himself corrected some of them late in his life.
⁶
However, we can easily recognize Leonardo’s statement as a forerunner of today’s Gaia theory—a scientific theory that views the earth as a living, self-organizing, and self-regulating system.
⁷

At the most fundamental level, Leonardo always sought to understand the nature of life. This has often escaped earlier writers, because until recently the nature of life was defined by biologists only in terms of cells and molecules, to which Leonardo, living two centuries before the invention of the microscope, had no access. But today, a new systemic understanding of life is emerging at the forefront of science—an understanding in terms of metabolic processes and their patterns of organization. And those are precisely the phenomena Leonardo explored throughout his life.

A SYSTEMIC THINKER

Leonardo da Vinci was what we would call, in today’s scientific parlance, a systemic thinker.
⁸
Understanding a phenomenon, for him, meant connecting it with other phenomena through a similarity of patterns. When he studied the proportions of the human body, he compared them to the proportions of buildings in Renaissance architecture. His investigations of muscles and bones led him to study and draw gears and levers, thus interlinking animal physiology and engineering. Patterns of turbulence in water led him to observe similar patterns in the flow of air; and from there he went on to explore the nature of sound, the theory of music, and the design of musical instruments.

This exceptional ability to interconnect observations and ideas from different disciplines lies at the very heart of Leonardo’s approach to learning and research. At the same time, it was also the reason why he often got carried away and extended his investigations far beyond their original role in the formulation of a “science of painting,” exploring almost the entire range of natural phenomena known at his time as well as many others previously unrecognized.

Leonardo’s scientific work was virtually unknown during his lifetime and remained hidden for over two centuries after his death in 1519. His pioneering discoveries and ideas had no direct influence on the scientists who came after him, although during the subsequent 450 years his conception of a science of living forms would emerge again at various times. During those periods, the problems he had struggled with were revisited with increasing levels of sophistication, as scientists advanced in their understanding of the structure of matter, the laws of chemistry and electromagnetism, cellular and molecular biology, genetics, and the critical role of evolution in shaping the forms of the living world.

Today, from the vantage point of twenty-first-century science, we can recognize Leonardo da Vinci as an early precursor of an entire lineage of scientists and philosophers whose central focus was the nature of organic form. They include Immanuel Kant, Alexander von Humboldt, and Johann Wolfgang von Goethe in the eighteenth century; Georges Cuvier, Charles Darwin, and D’Arcy Thompson in the nineteenth; Alexander Bogdanov, Ludwig von Bertalanffy, and Vladimir Vernadsky in the early twentieth; and Gregory Bateson, Ilya Prigogine, and Humberto Maturana in the late twentieth century; as well as contemporary morphologists and complexity theorists like Brian Goodwin, Ian Stewart, and Ricard Solé.

Leonardo’s organic conception of life has continued as an undercurrent of biology throughout the centuries, and during brief periods came to the fore and dominated scientific thought. However, none of the scientists in that lineage were aware that the great genius of the Renaissance had already pioneered many of the ideas they were exploring. While Leonardo’s manuscripts were gathering dust in ancient European libraries, Galileo Galilei was being celebrated as the “father of modern science.” I cannot help but argue that the true founder of modern science was Leonardo da Vinci, and I wonder how Western scientific thought would have developed had his Notebooks been known and widely studied soon after his death.

SYNTHESIS OF ART AND SCIENCE

To describe nature’s organic forms mathematically, we cannot use Euclidean geometry, nor the classical equations of Newtonian physics. We need a new kind of qualitative mathematics. Today, such a new mathematics is being formulated within the framework of complexity theory, technically known as nonlinear dynamics.
⁹
It involves complex nonlinear equations and computer modeling, in which curved shapes are analyzed and classified with the help of topology, a geometry of forms in movement. None of this was available to Leonardo, of course. But amazingly, he experimented with a rudimentary form of topology in his mathematical studies of “continuous quantities” and “transmutations,” long before this important branch of modern mathematics was developed by Henri Poincaré in the early twentieth century.
¹⁰

Leonardo’s principal tool for the representation and analysis of nature’s forms was his extraordinary facility of drawing, which almost matched the quickness of his vision. Observation and documentation were fused into a single act. He used his artistic talent to produce drawings that are stunningly beautiful and at the same time serve as geometric diagrams. For Leonardo, drawing was the perfect vehicle to formulate his conceptual models—a perfect “mathematics” for his science of organic forms.
¹¹

The dual role of Leonardo’s drawings—as art and as tools of scientific analysis—shows us why his science cannot be understood without his art, nor his art without his science. His assertion that “painting embraces in itself all the forms of nature” cuts both ways. In order to practice his art, he needed the scientific understanding of the forms of nature; in order to analyze the forms of nature, he needed the artistic ability to draw them.

In addition to his keen intellect and powers of observation, his experimental ingenuity, and his great artistic talents, Leonardo also had a very practical bent. As he pursued his investigations of nature’s forms, beholding them with the eye of a scientist and painter, the useful applications of his discoveries were never far from his mind. He spent a major part of his life conceiving machines of all kinds, inventing numerous mechanical and optical devices, and designing buildings, gardens, and cities.

When he studied water, he saw it not only as the medium of life and the driving force of nature, but also as a source of power for industrial systems, similar to the role that steam—another form of water—would play in the Industrial Revolution three centuries later. His extensive investigations of the flows of air and wind and the flight of birds led him to invent various flying machines, many of them based on sound aerodynamic principles. Indeed, Leonardo’s achievements as a designer and engineer are on a par with his accomplishments as an artist and scientist.

THE EYE AND THE APPEARANCE OF FORMS

In his
Treatise on Painting
, Leonardo makes clear that painting is the unifying perspective and integrating thread that runs through all his fields of study. From this work, a coherent conceptual structure emerges, which he might have intended to use for the eventual publications of his Notebooks.