Science is the captain and practice the soldiers.
Leonardo da Vinci1
The modern conception of politics has coincided with the unprecedented political and military success of Western European civilization, which has used the innovations of science and industry to conquer the planet, destroy older feudal or primitive political systems, and develop technological wonders hitherto only imagined by dreamers. In antiquity, Icarus was a symbol of human folly; in our times, Neil Armstrong walked upon the moon. Yet despite this success, modern political and social systems confront a deep crisis of self-confidence.
To understand this paradox, it is necessary to explain why for the last five centuries “modern” life has been said to differ from “antiquity.” Conventional accounts of Western political thought often identify the origins of modernity with Machiavelli. There are good reasons for this practice, for Machiavelli is unusual in describing his approach to human life and politics as “new” or a “departure” from the “ways” of “others.”2 Why then do so many commentators stress the “premodern” elements of Machiavellian political thought and date the modern period from Bacon, Hobbes, or Descartes, seeing in works like Leviathan and Discourse on Method the first fundamental departure from the theories of human nature, society, and history accepted in classical Greece or Rome and medieval Europe?3
To evaluate Machiavelli’s role in the emergence of modernity, one must focus on his claim to integrate both “long experience with modern things and a continuous reading of ancient ones” (Prince, Dedicatory Letter; p. 3). While this remark implies that “modern” writings, as distinguished from “ancient” ones, are useless, the phrase also suggests that if Machiavelli is an innovator, the source of that innovation is related to his “long experience” in Florentine politics. In reassessing Machiavelli’s teaching, therefore, I have emphasized his dispatches from the court of Cesare Borgia (1502/3), and especially his relationship with Leonardo da Vinci, apparently begun at Cesare’s court and continued in Florence (1503–1508). These events, which have been ignored by virtually all commentators, put Machiavelli’s writings in a new light.
Machiavelli claims that humans sometimes have the capacity to control chance and attempts to develop theoretical understanding toward this end. Leonardo’s understanding of the relationship between science and technology, epitomized by his role as consultant on the attempted diversion of the Arno River, provides an important example of this new perspective on human knowledge and activity. Whether one interprets the facts and documents in chapter one as evidence of a close friendship between Machiavelli and Leonardo, or merely as signs of parallel development, both thinkers use theoretical knowledge as a guide to the transformation and improvement of human life.
Although this novel understanding of theory and practice is a major step toward modern politics and thought, Machiavelli saw theory as an incomplete guide for practice, leading to the necessity for prudent statesmen or legislators. Without denying the role of Bacon and other transitional figures, I suggest that the fullness of modernity was not revealed until the seventeenth century, when Hobbes constructed a deductive theory of politics based on a combination of Euclidean geometry and Galileo’s physics. Hobbes’s claim that a geometric or scientific mode of reasoning will overcome the tension between theory and practice ushers in the specifically modern age, in which ideology or political religion comes to replace statesmanship. One key element in this further change is a reduction of Machiavelli’s complex view of human nature to a simpler calculus of pleasure and pain, permitting the substitution of formal models and abstract concepts for the prudential rules developed in works like The Prince and Discourses.
This reanalysis of Western intellectual and political history has substantive implications. When contrasted to Machiavelli, let alone the thought of antiquity, moderns from Hobbes and Locke to Hegel, Marx, and Nietzsche appear to base their understanding of human life on oversimplified concepts, erroneous assumptions, and biased interpretations of the facts. More than has been realized, the crisis of modernity may be traced to the tragic flaws of political philosophy and science in the three and half centuries since Hobbes.
Before reaching such a radical conclusion, it is essential to demonstrate that its premises are sound. First, then, we need to agree on the description of “modern” thought and society. Once modernity has been shown to entail a new relationship between theory and practice, it will be necessary to reconsider how the joint legacy of Leonardo and Machiavelli contributed to the perspective that came to dominate the West. Then, by describing more precisely why Machiavelli’s political theory as well as Leonardo’s scientific technology differ from modernity after Hobbes, the dangers of a total integration of scientific knowledge and political life will become more obvious.
To assess the fundamental problems confronting our civilization, it is first necessary to define it. This is more difficult than might appear: many substantive features that seem at first typical of “modernity” (e.g., equal rights of all individuals, popular sovereignty, secular science) do not distinguish our epoch from others without excluding some cultural experiences that also deserve to be called “modern.”4 Although I do not claim to have a solution to this definitional problem, I suggest that three related features deserve particular attention in defining the “modern” epoch: 1) the new relationship between theory and practice, which gave rise to the uniquely modern conception that humans can “control” or “conquer” nature for the “relief of man’s estate” (to use Bacon’s famous phrase); 2) the new scientific theories of nature and of human nature, which transformed human knowledge and technology; and 3) the resulting integration of scientific knowledge and practical wisdom, giving rise to political religions or ideologies in place of the dual realms of secular and divine authority which had characterized medieval Europe. Before describing the role of Machiavelli and Leonardo in the emergence of modernity, it will be helpful to explore these three defining features of our civilization in more detail.
The cultures that emerged in Western Europe with the Renaissance and extended their power to create global economic interdependence have various names: industrialized societies (though some—like New Zealand—are heavily dependent on agriculture), constitutional democracies (though some—like Nazi Germany and Stalinist Russia—were totalitarian dictatorships); secular or materialist economies (though some—like the Ayatollah Khomeini’s Iran—are based on theological fundamentalism).
No single set of political and social principles seems to define the universe of modern systems. For example, Rousseau’s Social Contract—the work often said to present the principles underlying the French Revolution—asserts that the principles of a free society can be reduced to “equality” and “freedom.”5 The American Founders would seem to have agreed, since the Declaration of Independence begins with the ringing words: “We hold these truths to be self-evident, that all men are created equal, that they are endowed with certain rights, and that among these are the rights to life, liberty, and the pursuit of happiness.” But the American revolutionaries did not extend the equality of rights to women, not to mention Native Americans and Blacks (groups which have only begun to gain equal status under the law in this century), and the French revolutionaries ultimately found it convenient to deny religious freedom to the Catholic Church and free speech to monarchists.
Indeed, when the history of modern political systems is considered from an outsider’s perspective, it is hard to deny that the “effectual reality” has been far from the supposed principles underlying constitutional governments. We are told that the English developed a government of law and representative institutions based on the extension of freedom and property rights to the individual—but in fact, this system was established by the forcible destruction of the independent cultures and social systems of both the Scots and the Irish (who were denied rights of self-government, forcibly removed from their land, and exploited economically as well as militarily in founding the British Empire). From the terror under the First French Republic to the repression under the Second Empire, France rose to political power and economic success at the expense of the feudal aristocracy and the disadvantaged poor. In the United States, the regional tensions of the Civil War were overcome by destroying the habitats and the populations of Native American tribes, forcibly removing the surviving remnants to “reservations” in order to open western lands to settlement and economic development. An even greater gap between principle and reality would, of course, be evident in the history of the Soviet Union (where the pretense of building communism was a mask for forcibly destroying the old peasantry and enriching the Communist Party elite), not to mention other modern totalitarian or authoritarian regimes.
In short, equality and freedom are absent in many modern political and social systems; political principles, whether stated or real, seem not to be the defining characteristic of modernity. Perhaps we will be on stronger ground if we begin by listing a set of cultural and social aspirations that might set modern societies apart from those of antiquity, the Middle Ages, or the so-called “Third World.” None of the following characteristics is perfectly realized in any modern society, but the combination of these goals has typically been present in modern cultures with varied political institutions and beliefs. To an unprecedented degree, all individuals—as individuals—expect to enjoy security, predictability, mobility, comfort, and progress. These attributes can be said to characterize the politically diverse versions of modernity of totalitarians and democrats; liberals, conservatives, and socialists; secular rationalists and religious fundamentalists.
Security. Modern societies seek to provide safety from both foreign attack and natural disaster for their elites—if not for all their members. The symbol of this transformation might be found in the word “enlightenment,” which stood for the movement to dispel the prejudices and vices of pre-modern life. In fact, the rise of modernity coincided with a more literal “enlightenment”: the installation of lights on city streets, making it possible to move safely among strangers in urban centers. Although never perfect, the promise that citizens can find their security in obeying the law renders obsolete the reliance on kinship or clan for self-defense. Individual security became the foundation of a market economy, in which valued goods can be offered for sale in the expectation that even when the poor have no money, they will not loot and steal.
Insecurity or violence is seen as a deep challenge to the basic principles of modernity, as is evident in the universal condemnation of uncontrolled criminal behavior by contemporary regimes. To be sure, those viewed as outsiders—whether Jews in Nazi Germany, kulaks and “bourgeois” in Stalinist Russia, or Native Americans, Blacks, Chinese, and other minorities at times in nineteenth-century America—have often been the target of organized violence or spontaneous harassment. Even so, modern regimes of the most diverse political principles have typically sought to establish a kind of “law and order” not found in primitive or feudal society. The best evidence of this is the uniform policy of repressing violent self-help, clan feuding, or aristocratic privilege—all of which provided security to selected groups at the cost of undermining universalistic norms.
Mobility. In pre-modern social systems, individuals or groups were often psychologically if not legally tied to a specific geographical place or social status. In the market economy, individuals need to be able to move through time and space in order to produce and consume goods and services; even where centralized planning and governmental ownership replaced free markets, some degree of geographical mobility was instituted (unless purposed “security” threats were used as a justification for denying them). This feature of modernity may explain the immense importance of systems of transportation and communication in contemporary life. Modern governments devote enormous resources to the construction of highways, bridges, railroads, seaports, and airline terminals, subsidizing the infrastructure for moving goods, people, and information—and, when technologies are being developed, sometimes subsidizing the introduction of new means of communication and transport.
Predictability. Moderns seek the predictability of economies that guarantee survival, laws whose provisions can be foreseen, and governments whose procedures will remain in place. The hyperinflation of Weimar Germany is widely viewed as the critical event destroying the legitimacy of that regime. Similarly, the catastrophe of Chernyobl destroyed the myth of the devotion to the common good by the Communist Parties of Eastern Europe (whose elites imposed secrecy and distributed gamma globulin to their own children before allowing the media to report the explosion). More recently, demands for “guaranteed” access to health care, full employment, and the safety of bank deposits—not to mention the attention paid to weather forecasts—reflect the characteristically modern desire for predictability.
Comfort. Security and predictability make it possible to devote resources to immediate consumption. Although the Welfare State was long challenged and, in some quarters remains controversial, its goal can be restated as the provision of material comfort to all fully eligible members of a modern society. This goal is shared by free market exponents hostile to the Welfare State as well as by Socialists for whom income redistribution and social equity are the principal goals of government. Modern technology provides, of course, the means by which physical discomfort and bodily disease can be remedied; insofar as individuals have “rights,” they are typically associated with a claim on access to the means of comfortable life.
The emphasis on comfort seems at first materialistic and this-worldly, for it leads to the use of resources to facilitate the daily routines of life. But comfort and the consumer durables facilitating it are desired by religious believers and atheists alike. The focus on convenience seems to have a rather different principle: the minimization of the time and difficulty separating an individual for the realization of desires or wishes. Typically modern inventions, from the flush toilet to the computer, have this common principle: reduce the obstacles to the completion of any task, whether necessary or frivolous.
Progress. Security, predictability, and comfort imply that the future will be better than the present. To make possible a continued expansion of the economic system, new technologies and scientific discoveries are indispensable. The promise of a continued sequence of benefits is the condition of allegiance to anonymous, heterogeneous communities in which individuals from diverse backgrounds can cooperate in safety and predictability.
Although the goals of security, predictability, mobility, comfort, and progress are elusive, these typically modern aspirations suggest the underlying principle that defines modernity. In one of the earliest explicit formulations of this principle, Sir Francis Bacon spoke of the “conquest of nature” for the “relief of man’s estate.” In Bacon’s view, it was necessary to organize science and technology for the end of political power; by integrating knowledge and technical ability, it would become possible to create “new natures upon old” and thereby direct the course of events.6
Why, one might ask, is the relationship between theory and practice a central defining characteristic of the modern epoch? However one distinguishes this stage in the history of Western thought—or, for that matter, in the development of human civilization more broadly—a simple fact comes to mind: only one civilization has come to conquer, both physically and culturally, virtually the entire planet. No culture, prior to that of the industrialized and commercial West, gave rise to a truly global economy, a global communication system, and even global (albeit embryonic) political institutions. In no other epoch have humans exploded nuclear weapons, developed in vitro fertilization, or placed artificial satellites in orbit, whereas in our time such technological capabilities have not only been developed, but—due to the character of our science and technology—they routinely transcend social or national frontiers.
This fact suggests that the relationship of theory to practice is characteristic of our civilization for a number of reasons. First, conceptualizing nature and human society in abstract or scientific terms—and then using these theories as the guide to political or economic practice—is not found in most civilizations: along with many other features of our own historical context, it is more problematic than it might first appear.7 The typically modern attempt to base political practice on principles that claim scientific truth has given rise to ideology, allowing leaders or elites to use popularized belief systems as a mechanism of social control and power.
Second, to develop a “theory” which can effectively guide practices or beliefs, it is necessary to establish an epistemological difference between statements that are scientifically demonstrable (facts) and those which express contingent preferences or goals of human action (values). When only the former came to be considered worthy of assent, modern science emerged as a new way of discovering and transmitting knowledge about the world. Such scientific knowledge, which changes even purely theoretical science from understanding to a kind of making, claims a universality not limited by language, belief, or social practice while serving as the foundation of technological transformations barely imagined before the Renaissance.8
A concrete example from cosmology will be useful. Recently, astronomers have been confronted with new observational evidence that the structure of the cosmos is highly uneven, with galaxies clustered in a way that was not predicted by established theories of the origin and evolution of the universe. The situation was reported in Science as follows: “The structures revealed by this celestial coverage are certainly sowing confusion. ‘We see these large-scale features and we don’t know how to make them. We don’t know how to make the structure of the universe,’ says Geller [Professor Margaret Geller of the Harvard-Smithsonian Center for Astrophysics]. For instance, minor energy fluctuations that cosmologists argue existed in the early universe appear to be insufficient seeds to give rise to such prodigious clusters of galaxies. ‘Gravity can’t, over the age of the universe, amplify these irregularities enough,’ Geller explains.”9
Whereas the layman—like the ancient philosopher—would speak of an inability to understand events which obviously surpass the human creative power, today’s physicists think they understand something only when they know how the causal forces make it. In a field like cosmology, using these terms sounds a little odd. In molecular genetics, in contrast, the equation of knowing and making takes the form of what has come to be called “genetic engineering”: to understand a gene, it must be cloned and its activity demonstrated in practice by experimental means.
Third, this new relationship between theory and practice has challenged beliefs and traditions concerning the gods or God. For most human peoples, the political and the theological—the domains of the sacred and the profane—have not been sharply divided: one need merely glance at Leviticus to see that the Mosaic Law does not make a sharp division between what we call the secular and the religious spheres of life.10 Ancient pagan philosophy inaugurated a profound dualism between scientific knowledge (episteme) and public opinion or belief (doxa), which Christian theology transformed into the equally profound dualism between faith and reason. Scientific theories claiming universal validity and practical applicability challenged such premodern approaches to the world, introducing a this-worldly or secular arena of social life whose government is a matter of human agency rather than divine will, and whose policies favor religious toleration. While science as we know it first appeared among the ancient Greeks, its social importance was therefore transformed by the claim that such knowledge could and should guide a technological and political transformation of the world.11
To be sure, all philosophy or science must to some extent differentiate between theory and practice. Since the Renaissance, however, a view arose that was not adopted even by those in antiquity who sought universal or rational knowledge of nature and of human nature: the typically modern conception of a successful conquest of nature and a definitive solution of human problems. In place of the ancient tension between philosophic knowledge and conventional opinion, moderns have seen the rise of ideologies derived from science (or pseudoscience).
I suggest that Machiavelli’s self-proclaimed novelty lies in a self-conscious adoption of this new approach to theory and practice, influenced by his personal encounters with Leonardo da Vinci between 1502 and 1508. Machiavelli’s political thought, when illuminated by the scientific and technical perspective developed by Leonardo, therefore symbolizes the beginnings of modernity. Even so, however, neither Leonardo’s artistic projects, engineering skills, and scientific theories, nor Machiavelli’s attempt to transform the norms and values of Christianity exhibit the fully modern characteristics epitomized by such seventeenth-century thinkers as Bacon, Galileo, Hobbes, Locke, and Descartes. In this view, modernity in the precise sense presupposes theories which claim to provide universal political guidance in the construction of an “eternal” and beneficent commonwealth here on earth, replacing the dream of a City of God with the construction of a city of men.12
What role did Leonardo da Vinci play in the emergence of modernity? This question would be important whether Leonardo influenced Machiavelli directly or was merely a leading representative of the intellectual transformations in the first years of the sixteenth century. The brief summary of Leonardo’s life and work in chapter one suggests the astounding variety of his activities; equally astonishing is the novelty of his understanding. In almost every field of his endeavors, Leonardo was an innovator. In many areas, these innovations were so radical that it took centuries for Western science, technology, and art to develop fully Leonardo’s initiatives. To be sure, scholars often point to similar developments by others in the Italian Renaissance.13 Without ignoring continuities, however, Leonardo’s innovations are often unusually radical, going well beyond anything attempted by his contemporaries or even his immediate successors. Even more important, Leonardo seems unique in the way his artistic, scientific, and technological innovations relate to each other.
In this interpretation, Leonardo’s principal legacy was the scope and the interrelatedness of the new ways of thinking he sought to introduce to virtually every human endeavor. To show this, it is important to survey—even briefly—some of his innovations in the arts (notably painting and sculpture), in science (relating mathematics to a new view of motion in nature), and in technology (including not only military weapons and productive machines, but large-scale projects of urban design and waterworks). In so doing, we will see that Leonardo’s frequent failure to complete specific commissions and projects was the inevitable price he had to pay for the awesome intellectual achievement of inventing the relationship between theory and practice that was to develop into modernity. It is fitting that his motto was ostinati rigore (“obstinate rigor”).14
Leonardo’s achievements are most evident in the fine arts, for his paintings are among his best-known legacy. Even here, however, the specificity of his contribution is not fully understood unless the works that have become familiar icons of Western culture, like the Mona Lisa or The Last Supper, are situated in a broader context. It is important to go beyond conventional “art history” when analyzing Leonardo’s works because he himself viewed art as a scientific activity. For Leonardo, painting is “more intelligible and beautiful” than poetry: “If poetry deals with moral philosophy, painting deals with natural philosophy. Poetry describes the action of the mind, painting considers what the mind may effect by the motions [of the body].”15 The primacy of art is its scientific status as an activity illustrating the potential of human making as contrasted to the mere description or observation of events.
Leonardo’s preference for painting over poetry thus mirrors the difference between the modern science as an activity of making and therefore controlling nature, and the ancient approach to science as merely understanding nature. This active view of art as a way of demonstrating knowing is evident in his Treatise on Painting as well as in a number of specific artistic innovations, each of which has been noted by historians as important in its own way. When considered together, Leonardo’s contribution to the artist’s representation of perspective, form, movement, light, and technique form a coherent initiative toward a radically different type of art than had ever existed before. Consider each of these five artistic domains separately.
Perspective. Much has been written about the role of three-dimensional perspective and its “humanistic” implications. What is fascinating in Leonardo’s art is the transcendence of Renaissance humanism through the invention of a radically new perspective which might almost be called surrealist: the aerial view, as if the artist and viewer are already flying in Leonardo’s imagined airplane or even a contemporary satellite. This new perspective first appears in Leonardo’s maps, such as the plan of Milan from the 1490s (Figure 1.4) or the plan of Imola drawn when he was in the service of Cesare Borgia in 1502 (Figure 1.5). Even more striking—particularly in the context of the argument of this book—are some of the maps intended to facilitate the rechanneling of the River Arno (Figures 1.6 and 3.2).
Looking at these maps, we see at once either direct aerial views (sometimes with the geographic detail of a satellite photograph, as in the map of Imola) or views from an angle (showing topography as well as physical location, as in the map of the Arno). Since both views are present in the map of Milan, which seems to be the earliest of the series, both innovations would seem to be part of the same break with tradition: moving the human observer through space at will to produce the point of view that is useful under the circumstances.
There were, of course, neither airplanes nor space satellites in the early sixteenth century. No human being had ever actually perceived space as it is presented in these maps. Yet for Leonardo, this new point of view immediately became a resource in painting. There is no better example than the most famous of his paintings—indeed, perhaps the most famous painting ever executed in the history of art: the Mona Lisa (Fig. 3.1).
Because this famous image has been rendered trite through over-familiarity, it is necessary to make an effort to look at it with a fresh eye. Consider the background, which Brizio calls “not a real landscape” but a “stratification of centuries.”16 How could a woman be so situated with relationship to the environment? The background appears to be seen from an airplane, much like the perspective in the map of the Arno (Figure 3.2). Somehow, then, Mona Lisa is solidly placed at an altitude which is not on the earth (unless she is standing on top of Mount Everest!). That is, there is something divine about the aerial perspective of Leonardo.
The importance of this new perspective concerns not only its artistic consequences, but its implication for the artist and his relation to the viewer. Classical perspective could be called “humanist” because it places the naturalistic visual perception of the painter before the observer: visually, both are on the same level, giving rise to the realism of the image. Look again at Leonardo’s Ginevra de Benci (Figure 1.1): the face is at eye level, and its “realism”—the sense that we would perceive the same thing if, instead of the painting, we were seeing Ginevra de Binci “in person”—rests on the equivalence of our visual experience when looking at the picture and the artist’s perception when painting it. The difference between the background of Ginevra de Benci (the bush, a juniper, being a verbal play on the subject’s name) and the aerial perspective behind the face in Mona Lisa is telling: no viewer can approximate the standpoint achieved by Leonardo. Rather, he raises us above our “natural,” earth-bound point of view. In this sense, the artist becomes a creator, in the image of the creative God of Genesis.
This interpretation is confirmed by Leonardo’s explicit statement in the Treatise on Painting that the “painter is lord of all types of people and of all things”; at that point, before the sentence from this passage cited above in chapter two, Leonardo adds:
If the painter wishes to see beauties that charm him it lies in his power to create them, and if he wises to see monstrosities that are frightful, buffoonish, or ridiculous, or pitiable he can be lord and god thereof; if he wants to produce inhabited regions or deserts or dark and shady retreats from the heat, or warm places in cold weather, he can do so.17
This assertion of the painter’s superiority as the “universal” human being suggests that the novel perspective emphasized here is no accident, but rather Leonardo’s visual realization of what he saw as the essential characteristic of painting.18
Form. On the surface, it would seem that the naturalistic presentation of form is characteristic of the Renaissance in general: one need only look at Michelangelo’s David to see the rediscovery of the tradition of Praxiteles and the ancient Greek sculptors. But Leonardo went beyond his contemporaries in at least two ways. First, he sought to discover hitherto unknown natural structures underlying the visible form; second, he was insistent that the functional or dynamic characteristics of things were essential to a presentation of their outer shape.
As he put it elsewhere, “Truly painting is a science, the true-born child of nature, for painting is born of nature, but to be more correct we should call it the grandchild of nature; since all visible things were brought forth by nature and these her children have given birth to painting.”19 Whereas Plato views manmade images as the lowest stage of the divided line, at the farthest remove from the forms, Leonardo inverts the hierarchy, asserting that “he who despises painting loves neither philosophy nor nature.”20
This attempt to go beyond his contemporaries illuminates aspects of Leonardo’s behavior that otherwise may seem inexplicable. As an illegitimate son of a Florentine notary, Leonardo did not have the status or wealth to engage in what today would be called scientific research and experimentation. In his time, for example, dissection was forbidden by the church. By using his interest in the nature of things to become a military engineer and urban planner, Leonardo was able to find patronage; he then used the power of his patrons to authorize such experiments as his research into the structure and function of the human body.21
Among the many examples of Leonardo’s radical quest to know the inner reality of outward form, one will suffice. Leonardo seems to have been the first human being to draw an unborn fetus (Figure 1.8). It takes but little reflection to realize the moral as well as religious obstacles that had prevented other artists from giving us this image. And as this drawing implies, Leonardo’s invention of a god-like perspective does entail scientific discovery as well as an artist’s image that transcends the “realistic” depiction of a pregnant human woman.
Leonardo’s Notebooks contain evidence that this radical use of art was completely intentional. For what was intended to be a book of anatomical drawings, he wrote:
I wish to work miracles. . . . And you, who say that it would be better to watch an anatomist at work than to see these drawings, you would be right, if it were possible to observe all the things which are demonstrated in such drawings in a single figure, in which you, with all your cleverness, will not see nor obtain knowledge of more than some few veins, to obtain a true and perfect knowledge of which I have dissected more than ten human bodies, destroying all the other members, and removing the very minutest particles of the flesh by which these veins are surrounded, without causing them to bleed, excepting the insensible bleeding of the capillary veins; and as one single body would not last so long, since it was necessary to proceed with several bodies by degrees, until I came to an end and had a complete knowledge; this I repeated twice, to learn the differences.22
Techniques for presenting form can therefore no longer be viewed merely as trial-and-error practices or artisanal secrets. The artist needs to know the inner nature of a thing (”complete knowledge”) in order to create an adequate image of its external shape or form. As will be evident, much the same is true of Leonardo’s radical innovations in the representation of motion.
Motion. Another element of Leonardo’s art struck his contemporaries and continues to astound art historians: images that portray both animate and inanimate movement. In his paintings and sketchbooks, we have visual evidence of an unusual ability to communicate the experience of motion, based on Leonardo’s insistence on understanding how nature works.
Leonardo’s radical innovations concern inanimate nature as well as living beings, both animal and human. Two instances of this ability will suffice here; each can be associated with activities during the period between 1503 and 1506, when Leonardo’s work was most likely to have brought him into personal contact with Machiavelli.
Leonardo’s fascination with water is evident in the repeated projects of rechanneling rivers, draining marshes, and redesigning urban environments. For example, his work at the port of Piombino required knowledge of the natural movements of water. While Machiavelli seems to have sponsored this project as Florentine technical assistance to ensure the political loyalty of Jacobo Appiani, Leonardo used the occasion to study the dynamics of inanimate nature in motion. Similarly, the projects to change the course of the Arno, as well as a later plan to create a canal from Milan to Lake Como, gave rise to drawings of the dynamics of moving water.23 Similar images of storms and other natural phenomena have a character unparalleled for their ability to seize the movements of nature.24
Leonardo’s use of scientific study as the basis of uniquely successful pictures of motion is even more notable with animate figures. As one art historian notes, “no one could rival him at rendering” a rearing horse.25 In representing the human form, Leonardo was even more explicit, criticizing his contemporaries for confusing the existence of muscles with their role in movement. As André Chastel put it:
Leonardo and his rival Michelangelo were both masters of the nude. Michelangelo’s figures were sculptural, revealing the play of every muscle. . . . But Leonardo, switching from anatomy to art, wanted his muscles to suggest the ‘movements of the soul.’ Perhaps with Michelangelo in mind, he writes in Codex Madrid I, “Do not make all the muscles of your figures apparent, because even if they are in their right places they do not show prominently unless the limbs in which they are located are exerting great force or are greatly strained. Limbs which are not in exercise must be drawn without showing the play of the muscles. And if you do otherwise, you will have imitated a bag of nuts rather than a human figure.”26
This new approach to depicting the movements of horses and humans was nowhere more evident than in the ill-fated Battle of Anghiari. Consider what the art historian Anna Maria Brizio writes of this mural on the wall of the Palazzo della Signoria:
The Battle of Anghiari belongs to a totally different cycle of experiences and concepts [than Florentine art in the first years of the sixteenth century]. A new dynamism breaks into it with shattering vehemence. Here again the protagonist is man, but a savage ferocity is present. The figures whirl around in a vortex of motions, as if the forces dominant in nature were unleashing the elements in an attempt to absorb man himself. An abyss separates Leonardo’s conception from the battles of Paolo Uccello, for example, of just 50 years before, in which every gesture and attitude is frozen in posture and every single part surrealistically composed and fixed within the network of the abstract and unchangeable relationships of specular perspective. With the Battle of Anghiari there is a violent break away from the perspective syntax of the 15th century; the group turns and rushes forward like a hurricane unleashed. Leonardo’s mind becomes increasingly more removed from humanism and passes on to consider in an ever wider and more cosmic sense the forces, motions, and elements ‘of heaven and earth’.27
Today, of course, we cannot see the original the way Machiavelli would have seen it every time he entered the Salla del Gran Consiglio. But we can see Rubens’s copy in the Louvre (Frontispiece), which “caught its meaning, its violence, and its confused fury, interpreting it with incomparable immediacy and authority.”28
Light. Leonardo’s innovations in representing perspective and motion would have been impossible without a radical innovation in the understanding of light. For example, he points out that the aerial perspective on a landscape requires that the tops of mountains be darker than their lower slopes (see Figure 3.2).29 More profoundly, Leonardo realized that to understand perspective, particularly in large paintings like The Battle of Anghiari, one had to understand how humans see—and that to understand the eye, one had to understand light.
The result of these investigations is not only visible in Leonardo’s paintings, but accessible to us in his Treatise on Painting.30 Although that work was not published until 1651, Leonardo left the manuscripts to his associate Melzi with the clear instructions and intention that it be published (not unlike Machiavelli’s action in leaving The Prince and Discourses to be published posthumously). That is, Leonardo clearly intended to transform the art of painting by making publicly known the science on which it rests. And that science seems to be part of an integration between theory and practice that is otherwise unknown in the history of art.31
Technique. Leonardo’s repeated attempts to develop radical innovations in the technique of painting and sculpture need to be seen in the context of his novel view of the relationship between theory and practice. Two examples will suffice, each a major political commission: the equestrian statue of Francesco Sforza, often called Il Cavallo, sculpted in Milan between 1482 and 1499 but never cast in bronze, and The Battle of Anghiari, painted in Florence between 1503 and 1506 but subsequently destroyed. The failure of each of these projects reveals, to its clearest extent, Leonardo’s attempt to use his scientific and technical knowledge to produce artistic innovations beyond the limits of known possibilities.
When Leonardo went to the court of the Sforza in 1482, Duke Ludovico (il Moro) wanted to erect an equestrian statue of his father Francesco that had been projected by his elder brother. Leonardo at first proposed a design on which Sforza is riding a rearing horse in life-size—a dynamic image of unheard of difficulty, for the statue would not have support for either of its front legs. The duke, ambitious and desiring permanent evidence of the legitimacy of Sforza rule in Milan, sought a bronze monument larger than had ever been cast. The biggest equestrian statue from antiquity—Marcus Aurelius in Rome—measures 4.24 meters (horse and rider combined); the monument in Venice to Colleoni by Leonardo’s teacher Verrocchio, completed in 1488 after a decade of work, is 4.0 meters (again, horse and rider combined). For the Sforza monument, the horse alone was to measure 7.2 meters. And, of course, since sculpture is three-dimensional, the increases in surface and weight are the cube of a linear measure.32
The enormity of the task made existing casting techniques impractical. Brugnoli says of the notebook containing Leonardo’s notes for the project:
Leonardo the innovator—this is perhaps the greatest significance of the Codex Madrid II folios on Il Cavallo. The problem that Il Moro presented to Leonardo, to cast a bronze horse four times greater than life size, could not be solved to the satisfaction of a perfectionist like Leonardo with the then existing methods of casting bronze. In this codex he clearly outlines a new method of casting bronze in a single operation. Once again Leonardo the innovator proved himself to be years ahead of his contemporaries: in fact we find the first reference to his new method of casting in the treatise on ‘Pyrotechny’ written between 1530 and 1535 by Vannoccio Biringucci. . . . Only two centuries after this new method was developed by Leonardo was it to be used for a large-size monument like the one planned for Francesco Sforza: the equestrian statue of Louis XIV of France.33
Ultimately, Leonardo’s sculpture was not cast due to the financial and material difficulties of Ludovico, who diverted Leonardo’s attentions to court pageants, and finally used the bronze for the statue to make cannon. When Sforza was driven from power in 1500, French soldiers destroyed the sculpture by using it for target-practice.
A second illustration of Leonardo’s use of innovative technique in the arts is The Battle of Anghiari. In addition to the novelty of its composition, Leonardo sought to use new materials for the wall mural in order to provide a more lasting and more vivid image. The mixture of oil and pigment that Leonardo apparently based on a text in Pliny proved faulty (some say due to adulterated linseed oil, others to the technique of heating the wall after painting, which had worked properly on a small-scale test but failed on the painting itself). For whatever reason, the entire painting was never completed and even the portion actually painted was eventually covered with plaster and repainted by Vasari during renovations of the building in 1560.34
The failure of these artistic projects is explained by the boldness of Leonardo’s attempt to integrate making and knowing, radically new techniques with daring artistic conceptions based on scientific studies of the objects represented. Despite the relatively small number of artistic works that he had completed, this close linkage of theory and practice had already established Leonardo’s fame by 1500, when he returned to Florence after the fall of Ludovico Sforza.35 Such works as were completed—especially those publicly visible, like The Last Supper or The Battle of Anghiari before its destruction—were not, however, Leonardo’s only legacy. Indeed, they were probably far less important than his manuscripts and the oral traditions they spawned among philosophers and scientists as well as artists.
Over the last century, many historians of science have explored and debated Leonardo’s role in the emergence of modern science. It is not possible here to resolve the detailed controversies involved.36 For present purposes, it will be more important to show the importance of the innovations proposed by Leonardo in his Notebooks. In no single case can we prove definitively that his ideas were the seminal contributions that actually changed the course of scientific inquiry: though manuscripts circulated and had great importance even if never published (as we know from the case of Machiavelli’s works), the essential point is the new temper and articulation of theory and practice which Leonardo everywhere epitomized.
Modern science is often traced to the discovery of the calculus by Newton and Leibnitz, which made possible a mathematical formulation of Galileo’s discovery of inertia and hence a true science of motion. Leonardo’s view of mechanics was based on a concept of “impetus” that fell short of Newtonian understanding of the laws of attraction between bodies on which classical mechanics was ultimately based. But Leonardo does seem to have discovered many of the key steps toward the scientific foundations of modern physics.
In the Notebooks, Leonardo makes it clear that mathematical knowledge is necessary for science of nature: “Let no man who is not a Mathematician read the elements of my work.”37 In itself, this is hardly an innovation, since it echoes the motto said to have been engraved over the portals of Plato’s Academy. For Leonardo, as for Plato, this is not merely a pedagogic prerequisite, but rather a basic characteristic of knowledge itself: “There is no certainty in sciences where one of the mathematical sciences cannot be applied, or which are not in relation with these mathematics.”38
Leonardo’s originality lies in the way he uses mathematics, and particularly in relation to other domains of scientific activity. Three points stand out: first, his emphasis on experimentation and observation; second, his departures from the substance of ancient mathematics and physics—paving the way for the modern sciences of motion; and finally, his constant awareness of the linkage between pure science and applied technology. A word on each.
That Leonardo emphasized experimentation and observation should be obvious from what has been said of his studies of vision and anatomy as the basis of innovations in painting. “All true sciences are the result of Experience which has passed through our senses, thus silencing the tongues of litigants. Experience does not feed investigators on dreams, but always proceeds from accurately determined first principles, step by step in true sequences to the end; as can be seen in the elements of mathematics.”39 While sharing the priority of mathematics in the Platonic tradition, Leonardo thus broke with the speculative—not to mention theological—form of much Renaissance Platonism.
The substantive innovations in Leonardo’s scientific notebooks repeatedly demonstrate his break with tradition. One example will have to suffice here. In ancient mathematics, there is a fundamental distinction between number (as in the whole numbers 1, 2, 3—or ratios 1:2, 1:3, 1:4) and measure. As a result, the ancients confronted the problem of incommensurability (e.g., the measure of the hypotenuse of a right triangle cannot be reduced to or made commensurable with a number). Perhaps more important, the ancients had difficulty with the mathematics of motion and acceleration, since they had no way of calculating continuous acceleration over time.40
Modern mathematics, and especially the infinitesimal calculus, require the notion of a point which is indivisible and has no measure. While not fully articulated in number theory until the nineteenth century, this conception was clear to Newton as the foundation of the mathematics of continuous or accelerating motion. Yet it was already articulated by Leonardo:
The point, being indivisible, occupies no space. That which occupies no space is nothing. The limiting surface of one thing is the beginning of another. 2. That which is no part of any body is called nothing. 1. That which has no limitations, has no form. The limitations of two coterminous bodies are interchangeably the surface of each. All the surfaces of a body are not parts of that body.41
The break with tradition is clear if one consults Aristotle’s Physics, which challenges virtually all of Leonardo’s statements (e.g., Physics, IV.211a–212a; VIII.261b–265a).
That Leonardo is working toward a new understanding is evident in a reflection on the number zero (nulla) that had been discovered by the Arab mathematicians.
Amid the vastness of the things among which we live, the existence of nothingness holds the first place; its function extends over all things that have no existence, and its essence, as regards time, lies precisely between the past and the future, and has nothing in the present. This nothingness has the part equal to the whole, and the whole to the part, the divisible to the indivisible; and the product of the sum is the same whether we divide or multiply, and in addition as in subtraction; as is proved by arithmeticians by their tenth figure which represents zero; and its power has not extension among the things of Nature.42
In place of the ancient approach to “nothingness” as a qualitative problem, we see here Leonardo focusing on issues of pure mathematics and geometry, searching for operational rules which can utilize a point of zero magnitude for computations in either time or space.
While the philosophical implications of pure mathematics might be left to specialists, the consequences of Leonardo’s radical break with the past are evident everywhere. To take the most obvious, long before Galileo’s observations with the telescope, Leonardo abandoned the geocentric view of the world upheld by tradition and the church.
The earth is not in the center of the Sun’s orbit nor at the centre of the universe, but in the center of its companion elements, and united with them. And any one standing on the moon, when it and the sun are both beneath us, would see this our earth and the element of water upon it just as we see the moon, and the earth would light it as it lights us.43
While other such examples could be catalogued, it is evident that Leonardo was as radical in the substance of his scientific views as in his approach to art.
Even more important is Leonardo’s explicit insistence on the integration of pure or theoretical natural science and applied technology. I have emphasized the importance of the project to redirect the Arno and Leonardo’s view that water has been the principal agent of historical change. Throughout his career, Leonardo was fascinated with the dynamics of water, seeking a scientific understanding of the form and power of waves, rivers, and other examples of moving liquid.
In the Notebooks, Leonardo projects a scientific work on this topic. Following in the tradition of Verrocchio and other painters, he presumed that assistants—in this case, probably Melzi—would complete the editing of his manuscripts. The notes directed to his editor therefore tell us much about how Leonardo intended his ideas to be brought together: “When you put together the science of the motions of water, remember to include under each proposition its application and use, in order that this science may not be useless.”44
This does not mean that Leonardo failed to see the difference between theory and practice. On the contrary, in the notes for rechanneling rivers—the example of Leonardo’s new science with which Machiavelli was most likely to have been familiar—the instructions are clear:
Of digging a canal. Put this in the Book of useful inventions and in proving them bring forward the propositions already proved. And this is the proper order; since if you wished to show the usefulness of any plan you would be obliged again to devise new machines to prove its utility and thus would confuse the order of the forty Books and also the order of the diagrams; that is to say, you would have to mix up practice with theory, which would produce a confused and incoherent work.45
The development of theoretical science presupposes its potential utility for human application; the development of technology presupposes its reliance on theoretical science. Theory and practice, fundamentally distinguished in pagan antiquity, are here cast in a radically new interactive relationship which was to emerge as the hallmark of modern society and the basis of its unprecedented material power.
The technological examples of Leonardo’s inventiveness—the submarine, the repeating canon, the automatic tool-making machine, the novel clock, etc.—are legion. It would be trivial to catalog them here. Nor is it essential to point out how many have been realized only in the twentieth century. Rather, it should be enough to note that his plans for the airplane mark the decisive intermediate step between the ancient symbol of Icarus (the desire to fly as the epitome of tragic hubris) and the modern reality of Neil Armstrong walking on the moon (the construction of flying machines leading to the utterance “One small step for man, a large step for mankind”).
Leonardo’s innovative genius touched many other areas of science and applied technology. For present purposes, it is most important to mention his attention to animal and human behavior, scientific fields that provided the basis for his concerns with the design of civil and military technologies to improve the quality of social life. In his art, Leonardo was particularly interested in the diversity of human faces—and the way they seem to symbolize differences in character and behavior. For example, when painting The Last Supper in Milan, he walked the streets to find the face that perfectly suited Christ and each of the disciples; his sketches depict all manner of grotesque as well as normal faces and gestures.46
In observing the varieties of human nature, Leonardo was disgusted by “rough men, of bad habits and little intelligence” and remarked on the many who were “mere channels for food, producers of excrement, fillers of latrines, for they have no other purpose in this world; they practice no virtue whatsoever.”47 Perhaps for this very reason, Leonardo seems committed to the spread of scientific knowledge and technology, believing that publication of his discoveries would have beneficial results. The mathematical study of light in the science of perspective “preeminently (tends to) elevate the mind of the investigator”; whereas “those men who are inventors and interpreters between Nature and Man” should be “esteemed” as “something in itself,” others—”boasters and declaimers of the works of others”—are little more than “herds of beasts.”48 Leonardo’s projected treatise on anatomy promises the reader “a true and complete knowledge of all you wish to learn of the human figure”; he will “speak of the function of each part in every direction,” so that “if it please our great Author, I may demonstrate the nature of men, and their customs in the way I describe his figure.”49
The claim to move from form to function implies that Leonardo can identify principles of behavior from the exterior evidence of the sense impressions of other living things. This is precisely what Leonardo sets out to do in a “Bestiary,” in which diverse traits are associated with different animals. For example, he finds “love of virtue” in the goldfinch, “sadness” in the raven, “gratitude” in the hoopoe, “avarice” in the toad, and “generosity” in the eagle. Unlike Machiavelli’s use of animals like the “lion, fox, and the wolves” to symbolize traits of human behavior, Leonardo seeks the corresponding traits in the life of other animals themselves.50 Hence, of the lion (Machiavelli’s exemplar of courage), Leonardo writes: “This animal, which is so terrible, fears nothing more than the noise of empty carts and likewise the crowing of cocks.”51
Such objective knowledge can be used for applied technologies in human affairs, not only in military and civil architecture, but in public health, politics, and urban planning. Leonardo’s innovations in the design of weapons and fortifications have been discussed in chapter one (see especially Figures 1.2, 1.9, and 1.10). Having discovered the parabolic trajectory of a cannon shell, he realized it would be necessary to develop forts with thick walls that were curved or angled—so that the attacker’s shells would ricochet harmlessly while the defense could fire over the fortified wall. Even with these discoveries, however, Leonardo also realized that massed firepower could inevitably give the offensive forces an advantage, reversing the balance favoring a well-entrenched defense that had characterized the entire history of medieval warfare.52 This explains Leonardo’s invention of a fortress with a moat inside the outer wall (so that attackers could be trapped and fired upon between the outer fortifications and an inner wall)—an innovation publicly proposed for the first time in Machiavelli’s Art of War.53
Leonardo therefore seems to have been one of the first to see how radically artillery could transform warfare.
If any man could have discovered the utmost powers of the cannon, in all its various forms and have given such a secret to the Romans, with what rapidity would they have conquered every country and have vanquished every army, and what reward could have been great enough for such a service.54
Leonardo apparently did not assume, however, that military technology would have the same efficacy in any hands; on the contrary, he sees the need to combine “means of offence and defense” with political institutions that permit “communities” to “maintain their good and just Lords.”55
Leonardo’s schemes for urban planning and the development or re-channeling of rivers for economic purposes have already been mentioned. These plans had a political and legal dimension that was essential to their conceptualization. For example, on the map of the diversion of the Arno for economic development, which Leonardo drew in the 1490s, he noted:
The law which establishes that those who want to make mills can conduct water through any land, paying twice its value.56
Even when drawing a map to show how water could be diverted for agricultural development and commerce, Leonardo reminds himself that legislation will be needed to finance the project and control its use.
It is obvious, particularly from the remarks concerning the importance of controlling sewage for reasons of public health, that such projects were viewed as the means of unifying scientific knowledge and political benefit. Such an interpretation is strengthened by the remarks indicating that Leonardo’s projects were intended to secure “revenue” and ensure political support: “even if he should not wish to reside in Milan he will still remain faithful in order not to lose the profit of his house at the same time as the capital.”57 In place of the principle of kinship or “consanguinity,” which characterized medieval societies, Leonardo wishes to substitute “property” as the link by which “communities obey and are led by their magnates.”58
Leonardo’s civil architecture—notably his designs for palaces for Governor Charles d’Amboise in Milan and for King Francis I in Romorantin—shows this same quest for a scientific view of a peaceful, economically prosperous life in which military danger has been removed to a distance. Having recognized that the new technology of cannon gave offensive armies a decisive advantage over medieval fortresses, Leonardo also seems to have sought the foundation of political success in economic prosperity, replacing the traditional ties of blood and native birth with self-interest. Consider the following:
And nothing is to be thrown into the canals, and every barge is to be obliged to carry away so much mud from the canal, and this is afterwards to be thrown on the bank.
Blessed is that possession which is watched by its owner’s eyes. Love conquers everything.
The ascending subjects are to their lord as the ivy is to the wall over which it climbs.59
The first of these suggests combining the self-interest of the barge-owners with the public need to maintain clean canals for reasons of health and transportation; the second can be interpreted to refer to the essential role of private property (establishing “love” of one’s own as the legitimate social bond); the last indicates that upward social mobility will enhance the external reputation of rulers without challenging their power.
The implication that Leonardo has in mind something like the emerging modern state is reinforced by another maxim written at the same time: “To order is an aristocratic act; to work is a servile act.”60 Indeed, like Machiavelli, Leonardo sees the need for strong rule to control and channel the potential “beast” in human nature:
Justice requires power, insight, and will; and it resembles the queen bee.
He who does not punish evil commands it to be done.61
Leonardo is thus clearly opposed to an egalitarian political and economic community, apparently suggesting to a ruler like Duke Ludovico that he can easily maintain his status by enriching his subjects under conditions that make them more dependent on his rule.
This survey of Leonardo’s legacy confirms that his capacity to imagine technological wonders was derived from a coherent and revolutionary perspective on human art, human thought, and human action. No one before Leonardo ever attempted such an integration of theory and practice. Perhaps more important for our purposes, Leonardo extended his understanding of science and technology to outline a radically new vision of human society and politics—a vision which intimates the future of modernity in the West.
As indicated by the historical facts noted above, Machiavelli must have known about many of the projects in which Leonardo’s new articulation of theory and practice was revealed: the project for redirecting the Arno (including the maps illustrating a new aerial perspective), The Battle of Anghiari (with its novel artistic composition as well as problematic material techniques), the attempt to build a flying machine (which Leonardo apparently pursued actively while in Fiesole during 1504/5), and even Il Cavallo (the ill-fated statue of Sforza, whose grandiose dimensions were visible before the uncast model was destroyed at the fall of Ludovico). Even if Machiavelli had never met Leonardo personally, he would have been aware of these innovations from his everyday experiences and his circle of friends and acquaintances.
Although Machiavelli is silent about Leonardo’s art, for example, documentary evidence proves he was aware of the open controversy between Leonardo and Soderini (with whom Machiavelli was so closely associated) concerning payments to the artist and his failure to complete The Battle of Anghiari.62 The dedication to The Prince, where Machiavelli compares his analysis of the nature of princes and of peoples to an artist’s perspective on mountains and valleys,63 echoes a passage in Leonardo’s Notebooks,64 suggesting that Machiavelli may have known Leonardo’s manuscript on The Art of Painting—or at least the ideas it contains.
Any one similarity of this nature could readily be dismissed as fortuitous. In chapter three above, however, I have analyzed at length the famous allegory of fortune as a river in The Prince, showing the connection between the view of history it represents and not only the abortive plan to redirect the channel of the Arno, but above all its relation to Leonardo’s writings on hydraulics and history.65 While some authors have assumed that similar ideas concerning floods and history were “probably arrived at independently by the two men,”66 in fact Leonardo’s theories of hydraulics and their relation to human affairs were far from commonplace;67 in the biblical view, as the stories of both Moses crossing the Red Sea and Noah’s construction of the ark testify, floods are part of God’s plan—and only God can control the resulting inundations. The similar novelty underlying the work of Leonardo suggests that Machiavelli’s thought was in some way influenced by conversations between the Second Secretary and the great artist-scientist-philosopher. Even if the skeptic rejects all such circumstantial evidence, there remain many striking parallels in the thought of the two famous Florentine contemporaries.
Machiavelli often speaks of the need for “bold” action at critical moments in history. On the back of a sheet with material for the diversion of the Arno, Leonardo wrote a common proverb:
When fortune comes, seize her in front with a sure hand, because behind she is bald.68
Whatever the historical effects of any single invention or theory of Leonardo, the boldness of this innovator was probably his greatest legacy not only to Machiavelli, but to Western history more generally.
Like Leonardo, Machiavelli died having left behind relatively few works available to the public: for both, many practical endeavors ended in failure; for both, the most significant works were not widely accessible. Leonardo’s Mona Lisa was not in a museum; he kept it with him when leaving Florence, and it found its way to King Francis I—and only later to the Louvre, where it could be seen by millions of visitors; Leonardo’s Treatise on Painting was not published until the seventeenth century, and most of his Notebooks were largely unknown until late in the nineteenth century. Machiavelli’s Mandragola had been performed and his Art of War and Florentine Histories published before his death, but the Discourses on Titus Livy and The Prince were not published until 1531 and 1532 respectively. Yet, like Leonardo, Machiavelli’s historical legacy has been enormous, first by word of mouth and private circulation of manuscripts, and of course ultimately by publication and fame.
To summarize Machiavelli’s achievement, it is useful to consider how he changed the understanding of human history and action. For this purpose, it is well to return to The Prince. In chapter fifteen, when Machiavelli speaks of “imagined republics and principalities,” the thoughtful reader is tempted to recall one exemplar of each of these kinds of regime: the Republic of Plato and The City of God of Augustine. More broadly, then, Machiavelli is critical both of the “best regime” of the ancient (pagan) philosophers—presumably including Aristotle’s Politics or Cicero’s De Republica along with the work of Plato—and of the Christian ideal of the “kingdom of God” (whether in its biblical or medieval formulation). Philosophers and theologians alike have explored what we call “theories” of human nature and political life, but these theories are defective when considered in the light of practice.
Machiavelli’s criticism of these defective theories entails a redefinition of the concept of virtù. For the ancient pagan philosophers, virtue (arete, virtute) meant human excellence either in moral and ethical action or in theoretical wisdom: as Plato’s Republic illustrates, the four cardinal virtues were courage, moderation, wisdom, and justice. For the Church Fathers and Christian theologians, virtue meant belief in God, submission to his will, and love of fellow-men or, as the New Testament puts it, “faith, hope, and charity.”
Although there is debate on the exact meaning that Machiavelli gives the word virtù, there can be no doubt that he departs radically from both the Platonic and Christian ideals. For some, Machiavellian virtue is merely “ingenuity” and “astute” manipulation of power; for others, it is prudent and effective political leadership in the founding and maintenance of republican government. What is obvious is that—to risk an anachronistic phrase—Machiavelli engages in a transvaluation of values, converting both pagan and Christian ideals into a practical, this-worldly form of human excellence.
To define Machiavelli’s novelty with more precision, it is necessary to consider the practical exemplars or models which replace the “imagined republics and principalities.” Machiavelli’s two main works, The Prince and the Discourses, represent the substitution of “realities” in human history for the defective theories of the past. In the Discourses, Plato’s Republic is replaced by the historical example of Republican Rome (as it is known to us through the writings of Titus Livy and other historians); in The Prince, Jesus as the “prince of peace” is replaced by the example of Moses as human legislator (with the Old Testament tacitly serving as a historical account equivalent to Xenophon’s Cyropedia or the works of Polybius, Livy, and other pagan historians who describe Cyrus, Theseus, and Romulus as founders of human regimes).69
Machiavelli’s teaching is thus a radical attempt to refocus human energy and thought on this-worldly political action. The apparent immorality of his advice to rulers is not, in this view, primarily undertaken with the view of encouraging leaders to exploit their power for narrow selfish ends.70 On the contrary, as careful readers like Rousseau were at pains to emphasize, Machiavelli seeks to rehabilitate the practice of republicanism as exemplified by pagan Rome.71
In this reading, emphasis on the need for individual leadership, which is so obviously a principal teaching of The Prince, is necessary for “the common good.” Since the chief foundations of all societies are “good arms and good laws,” it is necessary to have leaders who combine the way of the “beasts” who do not share human moral standards (the skills of “the lion and the fox”) with those of “man” (who governs by law or the standards of praise and blame we associate with morality). The virtuous Machiavellian leader is, therefore, the founder or, to use the phrase of the Discourses, the “prince of a republic” who uses power in a tough-minded and unscrupulous manner for the benefit of the community.
Machiavelli’s most extensive treatment of the relationship between human knowledge (or science) and action is doubtless his famous allegory of fortune as a river in chapter twenty-five of The Prince. In chapter three, this passage was analyzed in the light of Machiavelli’s experience in attempting to redirect the Arno River, in which Leonardo was a consulting engineer. Moreover, I have shown that virtually the same image of the floods as the principal agent of historical change is spelled out in detail both in Leonardo’s own Notebooks and in Machiavelli’s Discourses on Titus Livy. There is every reason, therefore, to assume that this allegory presents a basic teaching in concise, easily remembered form.
For Machiavelli, human wisdom can respond to the challenges of history. Just as the allegorical “river” of fortune can sometimes be controlled by constructing “dikes and dams,” historical accidents can sometimes be controlled by the establishment of “good arms and good laws.” This prospect of using scientific knowledge for human betterment, like so many of Leonardo’s projects, rests on technical or scientific understanding of all the relevant natural forces. If the effects of floods can be controlled by science and technology, as Leonardo proposed in developmental schemes for the rulers of Milan, Florence, Rome, and France, then the effects of historical unpredictability or fortune should likewise be limited by understanding human nature.72
I have argued that, in the allegory of the river in chapter twenty-five of The Prince, “water” stands for events, a “flood” or “violent river” is a war or foreign invasion, the “earth” human beings, the “trees” the natural resources, and the “buildings” the arts, sciences, and civilizations made by humans. “Dikes” (representing military forces or “good arms”) and “dams” (”good laws”) are the technological inventions that can control the “impetus” of potentially dangerous natural forces, but their use requires “virtue” or the effective use of human knowledge, strength, and courage.
Book II, chapter five of the Discourses confirms that the river allegory represents Machiavelli’s theory of history (and not—as some have suggested—merely a commonplace of Renaissance thought). Three points are worth adding in this regard. First, the “measures which Christianity adopted vis-à-vis paganism” are the principal human example of the catastrophic discontinuities in history; the “heads of the Christian religion . . . burnt the works of poets and historians, destroyed images and spoiled everything else that betokened in any way antiquity” (ibid., p. 289).73 Second, it follows that Christianity is simply one religion akin to others; such religious persecutions destroy the common argument against “those philosophers who want to make out that the world is eternal” and hence reduce the biblical account of God’s creation to a human “institution” (ibid., pp. 288–289).74 Third, the repeated historical or natural catastrophes “obliterating the past” are, for Machiavelli, salutary; “when the craftiness and malignity of man has gone as far as it can go, the world must needs be purged . . . so that mankind . . . may adopt a more appropriate form of life and grow better” (ibid., p. 290).75
Machiavelli’s analysis of Brunelleschi’s failed project of flooding Lucca not only confirms the importance of political prudence when implementing such technical projects, but suggests that attempts to divert a river will fail if they are inconsistent with the code described here. Since the relevant chapter of Florentine Histories (IV, 23) is quite short—sometimes a sign of great importance in Machiavelli’s works—it is worth citing in full:
In those times there was a most excellent architect in Florence, called Filippo di ser Brunelleschi, of whose works our city is full. So great was his merit that after his death his likeness in marble was placed in the principal church of Florence with an inscription on the pedestal that still gives testimony of his virtues to whoever reads it. He showed how Lucca could be flooded, considering the site of the city and the bed of the river Serchio, and so much did he urge it that the Ten commissioned the experiment to be made. But nothing came of it other than disorder in our camp and security for the enemy, for the Lucchese raised the earth with a dike on the side where the Serchio was being made to come and then one night they broke the dike of the ditch through which the water was flowing. Thus, the water found the way toward Lucca blocked and the dike of the channel open, and it flooded the plain so that not only could the army not get near the town but it had to draw off.76
Several things in this chapter deserve mention: first, Brunelleschi is described as a “most excellent” architect, whose “merit” and “virtue” were sufficient to produce lasting fame; the flaw in the project does not seem to have been a faulty understanding of the scientific facts; second, since technological stratagems in warfare are vulnerable to countermeasures, knowledge of the likely human response to their use is absolutely essential to success; scientific knowledge can be pernicious unless guided by political prudence; and finally, because Brunelleschi’s attempt inverts the image of The Prince—in this case dikes are used to create a flood rather than to prevent one—the failure might be taken as a covert suggestion that pacific uses of technology and law may be more likely to succeed in controlling fortune than military ones.77
This allegory of fortune as a river is, moreover, not to be taken too literally: though rivers, harbors and irrigation systems are of immense import to civilized states, the political and military implications of science and technology are not limited to them. But for Leonardo, an understanding of the motions of water (and not, as with Galileo, Newton, and subsequent physicists, the trajectories of falling bodies associated with projectiles) was the critical issue at the foundation of a science of nature.78 Hence the allegory of the river suggests the project of using science and technology—as Leonardo’s Notebooks show he thought possible—to transform the human condition to one of hitherto unimagined convenience, security, and plenty. Could the prospect of such a science have played a role in Machiavelli’s claim to have opened a “new way” in political thought?
These passages show that Machiavelli’s allegory of the river is not simply derived from an attempt to rechannel the Arno (whether the military plan on which the city of Florence consulted Leonardo, or the more pacific and economic design that Leonardo first envisaged a decade earlier). Rather, Machiavelli’s allegory is an extended and complex code representing the possibility that human initiative could channel political events if guided by a satisfactory political as well as natural science. And it is precisely this image of human history as well as the potential of a science capable of controlling nature that Machiavelli might have borrowed from Leonardo.
It may be asked whether the several parallels between Leonardo’s Notebooks and Machiavelli’s Prince and Discourses form the basis of the latter’s claim to novelty—and if so, why Machiavelli never discusses Leonardo openly. I suggest that the answer to the second question depends on the first. Machiavelli’s novelty must in some way be associated with the reason for his praise of the political life of antiquity. Republican Rome is the exemplar of practical politics because it provides an antidote to the passivity and otherworldliness of Christianity; praise of antiquity is directed to the needs of the present:
there is nothing more necessary to a community, whether it be a religious establishment, a kingdom or a republic, than to restore to it the prestige it had at the outset, and to that one should desire. (Discourses, III, 2; p. 390)
Political success needs to be under human control. It is precisely on this score that Rome—not to mention Christianity—is defective: even Roman greatness was due to accident, not human design. Even the highest examples of human history prior to Machiavelli’s time need to be corrected by a science of human nature and political institutions.
While any religion can be dangerous if it discourages human initiative, Christianity tends to be especially pernicious. Humans orient their action to a goal or target, and for Christians, that target is “an imagined principality”: the city of God governed by the “prince of peace.” Machiavelli repeatedly described himself as seeking to orient the human gaze elsewhere: not to heaven (to gain it), but to hell (to avoid it).
This attempted reorientation and its political intention is clearly stated in the letter to Guiccardini cited in chapter two, in which Machiavelli claims that “I believe the true way of going to Paradise would be to learn the road to Hell in order to avoid it.”79 Political life needs to be reoriented to the practical problem of avoiding such hellish outcomes as foreign invasions and civil wars. To do so, Machiavelli must lead the public at large to think of this-worldly pleasures as legitimate and proper ends of their activity.
In setting forth Machiavelli’s theory of history in chapter three, I analyzed Machiavelli’s Mandragola as an example of this attempt to reorient popular attitudes by an astute use of the dramatist’s craft. As will be recalled, the lesson of the play is summarized by the song composed as a prologue: “let us follow our desires . . . because whoever deprives himself of pleasure . . . doesn’t know the tricks of the world.”80 Moreover, Machiavelli wrote other works that suggest the same goal of using a combination of political skill and human knowledge to replace Christian doctrine in order to organize and control human fortune. Among these is Belfagor, a short tale in which a devil named Belfagor bets Satan that he can control a human woman, comes to earth, and is outwitted by a clever peasant, who gains wealth and pleasure in the process. Like Mandragola, this story addressed to the popular reader teaches that this-worldly success is possible for those willing to challenge the traditional image of Christian piety. And like Mandragola, the story suggests that—as Mandeville later put it—”private vices” can be the foundation of “public virtue.”81
Natural science can assist in this process: Callimaco’s seduction of Lucrezia in Mandragola is based on knowledge of the presumed properties of the mandrake root. But natural science cannot by itself persuade the virtuous Lucrezia to engage unwillingly in adultery: such knowledge can direct humans to control outcomes formerly attributed to chance or fortune, but doesn’t provide methods that are certain to succeed. Ultimately prudence and political judgment will be needed to found a new political regime or to liberate people from sterile rules imposed on them.
Machiavelli’s new way therefore does not promise certainty of success and a definitive conquest of fortune and natural necessity. At best, he says in chapter twenty-five of The Prince, humans could control “about half” of the historical events commonly attributed to chance. Individual leadership and political prudence are—and will always remain—essential to human success. In part this follows because the rules of his new political science are complex, dependent on circumstances or “accidents,” and in need of application based on good judgment or what the ancients called “practical wisdom.”82
The need for leadership and prudence is illustrated by Machiavelli’s advice with regard to fortresses (Prince, ch. 14). Fortresses are an architectural (material) component of “good arms”; they could be said to represent the engineering that Leonardo’s scientific technology could contribute to human politics.83 But although Machiavelli says that there is no simple rule about when to build fortresses, such material forms of power are less effective than the commitment of a republican citizenry; because “it is not fortresses but the wills of men that keep rulers in power,” fortresses are “generally much more harmful than useful.”84 Ultimately, it is the human dispositions and virtues that are central to political success, not the technological devices derived from a scientific understanding of inanimate nature. Prudence or practical wisdom (the phronesis of the ancients) is superior to both theoretical wisdom (sophia) and art or technology (techne).85
According to Machiavelli, most innovations do not change war and politics in any fundamental way. In the chapter of the Discourses devoted to the military effects of “new devices” as well as “new words,” for example, Machiavelli advises that a “good general” should “try to confuse the enemy” with them, but only if they have “more truth than fiction” since such innovations often fail if they are “fictitious” or “flimsy”; most of the chapter concerns “new words” or deceptive tricks, not technology.86 Earlier in the same work, when dismissing most technical inventions as ineffective, as well as in Book IV of The Art of War, Machiavelli uses the example of “scythed chariots” (one of the devices drawn by Leonardo) and indicates countermeasures that were effective both when these devices were used by the “Asiatics” (the example described in Xenophon) and by Archelaus against Sulla.87
Machiavelli’s apparent indifference to military technology may be, however, intentionally deceiving; there has apparently been one technological change in human history that greatly transforms human politics—albeit without modifying the primacy of political prudence. Actually, Machiavelli devotes considerable attention to the effects of “cannon” and “artillery” on both the effectiveness of infantry and the design of fortifications. In this case, although Machiavelli insists that the technological transformation does not diminish the primary importance of the infantry and the virtù of its soldiers, he admits that the innovation has simply superseded ancient weapons in sieges88 and necessitates the redesign of fortifications along lines like those described by Leonardo. For the infantry, in addition to such traditional weapons as the crossbow and bow, Machiavelli advises adding “the harquebus, a new weapon, as you know, and necessary.”89
Such innovations apparently have had a transforming effect on the technological component of warfare of the utmost political importance. For example, artillery inherently favors the offense over the defense, and hence ends the effectiveness of the traditional defensive fortifications.90 This does not end the decisive role of the infantry in warfare, as some thought; quite the contrary, “any who think artillery all-important must be either of little prudence or must have thought very little on these things.”91 But artillery does completely change the political dimension of warfare: whereas formerly it was thought that soldiers should be drawn only from those in virtuous occupations (”tillers of the soil, smiths, horseshoers, carpenters, butchers, hunters, and the like”), under the new conditions of warfare, any citizen—including “falconers, fishermen, cooks, pimps, and whoever makes a business of providing pleasure”—can be a good soldier if properly motivated.92
Machiavelli’s emphatic preference for a citizen army (e.g., Prince, ch. 12) is, in part, linked to the effect of modern artillery and military technologies with which Leonardo was expert. But Machiavelli could not openly stress these technological factors without running the risk that readers would erroneously think them “all-important.” Machiavelli therefore puts his stress on the human element: it is always prudent to espouse the benefits of a citizen army, motivated by virtù to defend its homeland. Moreover, because technological innovations make the courageous and motivated pimp as valuable as the courageous and motivated yeoman farmer, the egalitarian implications of military service flow directly from the effects of artillery.
This exposition not only explains what Machiavelli and Leonardo share, but also may indicate why Leonardo’s example is not discussed in Machiavelli’s works. The two great Florentines share a focus on the bodily things: le cosi (as Machiavelli so often calls “politics”).93 Both seek to improve human existence through knowledge of the movements and functions of bodies. While accepting the impermanence of an individual human life, both seek an art that can achieve lasting excellence that will surpass the greatest works of classical antiquity. But whereas Leonardo’s principal endeavors were focused on the arts of painting, architecture, and the science of moving objects, Machiavelli’s work concerned human communities more directly, in politics but also in history and in drama or poetry.94
This difference may explain the differing role of patriotism in Leonardo and Machiavelli. Leonardo was, so to speak, a citizen of the world: he served not only Cesare Borgia and Republican Florence, but the Milanese, the Medici, and the French; by 1507, he was in the service of King Louis XII—and, of course, he was ultimately to die at Amboise in the service of Francis I. Machiavelli, in contrast, was by principle as well as by passion a Florentine patriot, as epitomized by the eloquent plea to Italy in the last chapter of The Prince. It follows that, by the time Machiavelli started to write The Prince and the Discourses in 1513, he could well have been reluctant to avow openly his debt to Leonardo’s scientific and technical knowledge: on the one hand, Leonardo’s expertise did not prevent failure in two conspicuous Florentine projects (the abortive military plan to divert the Arno and the unfinished, ill-fated painting of The Battle of Anghiari); on the other, Leonardo served foreign rulers—the Milanese, the Medici, and the French and even Cesare Borgia—thereby demonstrating the defect of technical knowledge that is not in the service of political principle.
While Machiavelli may have opened the route to modernity, his teaching does not envisage the definitive “conquest of nature” for the “relief of man’s estate” described by Bacon.95 Ultimately, Machiavelli’s view of human nature is limited by the accidents of time and place, which give rise to parochial attachments and imperfect outcomes. It is otherwise for Hobbes. A century and a half later, as one can see in his Leviathan, modernity appears in its fullness as a significant extension of the claims for science and human politics.
For the purposes of this exposition, it will be necessary to focus on Hobbes’s Leviathan. From the outset of his best-known work, Hobbes integrates three principal themes: first, a science of nature (more specifically, Galileo’s new physics of motion) capable of beneficent technological application; second, a theory of human behavior (based on a logically consistent redefinition of terms) that forms a deductive system of confirmable hypotheses; and third, a transformation of traditional Christian doctrine in order to legitimate the practical application of the resulting political theory. Hobbesian theory is thus both a geometric tautology and a self-fulfilling prophecy, using what is today called the “social construction of reality” to found a peaceful, orderly, and powerful commonwealth.
For Machiavelli, as for Leonardo, a hypothetical-deductive science based on mathematical formalization, capable of explaining the motions of bodies and serving to generate beneficent technology, was little more than a promise. Hobbes found himself in a very different situation. On the one hand, as we know from his biographer Aubrey, the experience of reading Euclid had astonished Hobbes, showing him the possibility of universally valid demonstrative proofs. On the other, the physics of motion developed by Galileo provided a scientific theory generating a consistent system of definitions, principles, and hypotheses capable of empirical verification.96 Because such a blend of mathematics and physics can be used to guide technological construction, Hobbes can propose a relationship between theory and practice that reaches more optimistic conclusions from premises similar to those of Machiavelli.97
The Author’s Introduction to Leviathan exhibits all of these features. Hobbes begins the Introduction with a comparison between God as maker of the universe and man as maker of the commonwealth: humans are viewed as creators of political order, just as the Christian God is the creator of the world. This creation of political institutions is compared to “automata”: self-moving machines, like a watch, which represent successful technological innovations based on scientific knowledge.98 To this end, however, it is necessary to redefine terms and generate observational means of testing the resulting propositions. Only then can political institutions be designed and implemented so that natural propensities of humans generate political stability and even something approximating the premodern virtues.
Hobbes’s procedure is as follows. At the outset, he shows that human behavior is the product of matter in motion. The natural condition of all bodies is the inertia described by Galileo: motion continues until external forces or objects intervene. Applied to humans, this means that all thoughts and ideas are produced by particles or bodies which have communicated an environmental event to the individual brain (Leviathan, chs. 1–4; pp. 25–45).
This view has epistemological consequences. If all thought is the result of environmental conditioning on a “blank slate,” all concepts are conventional; as Locke argued in the Essay on Human Understanding, there are no “innate ideas” and no ways of knowing the “essence” or inner nature of things. It follows that the redefinition of any concept can be undertaken as long as it is consistent with empirical evidence. Hence it is both possible and necessary to redefine all basic terms describing human nature and social behavior, abandoning the natural teleology of Aristotle and the Thomist tradition (Leviathan, chs. 5–11; pp. 45–92).
Because inductive categories are limited by the experience of the individuals who use them, the only universal knowledge takes the form of a deductive system based on the model of Euclid’s geometry. Only such a system can produce hypothetical statements about the world which are rigorous and capable of demonstration. “Absolute knowledge”—the testimony of a witness in a specific event—is utterly unreliable; instead, hypothetical knowledge (statements in the form “if . . . then”) can be the basis of deductive theorems whose descriptive accuracy is tested by experience (Leviathan, ch. 9; p. 75).
This approach explains why Hobbes’s theory is based on a model of the “natural condition of mankind.” Hobbes replaces the historical science of Machiavelli with a quasi-geometrical model of the state of nature based on a formal definition of natural right and natural law. The natural right to self-preservation, understood as the human equivalent of inertia in physics, is an unlimited claim on all things, giving rise to “a perpetual and restless desire of power after power, that ceases only in death” (Leviathan, ch. 11; p. 86). So defined, this basic principle of human behavior can readily be confirmed by observing human selfishness. Although Hobbes uses the evidence which served as the basis of Machiavelli’s prudential theory, he thus transformed selfishness into an equal “right” of all humans that could be the foundation of a deductive science.99
Since all humans have an unlimited right to all things, the basic problem of social behavior is the ubiquity of conflict: the “natural condition of mankind” is a “war of all against all.” To avoid a life that is “solitary, poor, nasty, brutish, and short,” individuals form a society or “commonwealth” based on a social contract or “covenant” (Leviathan, chs. 13–16; pp. 101–136). Because this view of human nature resembles the account in Glaucon’s restatement of the Sophist theory of justice (Republic, II.358e-360d), Hobbes’s premises are hardly novel—but he uses them as the basis of a radically new theoretical system.
According to Hobbes, natural right must be distinguished from the law of nature, which consists of the obligations established by reason. Hobbes completely transforms the traditional or Thomist concept of natural law by converting moral injunctions into a logical tautology. The first law of nature is formulated as follows: “seek peace if you have hope of obtaining it, and enter into war if you do not.” Cooperate if you think you can preserve yourself by so doing; compete if you think that you cannot preserve yourself by cooperating. Since each individual is the only judge of which branch of the law of nature applies in any situation, there is no way of disproving this rule of behavior. If humans are obeying the government; they have followed the first branch of the law; if they disobey the government, obviously they are following the second.
Hobbes’s commonwealth is thus embedded in—and always risks reverting to—the state of nature. It is impossible to avoid this outcome merely by exhortation or threat: even if a subject has been justly condemned for violating the law, the criminal who perceives enforcement of the law as a threat to continued life will return to the state of nature. Because no covenant can entail the surrender of the natural right to self-preservation, individuals can and will resist punishment. More generally, subjects can be expected to obey the sovereign only when they judge that the benefits are greater than the costs.
The apparently authoritarian power of the Hobbesian sovereign is misleading, since Hobbes’s carefully redefined terms describe a “representative” government based on the “consent” of the subjects. This paradox can only be understood by considering the problem of applying Hobbes’s theory to practice. After spelling out his theory of the commonwealth, Hobbes concludes Part 2 of Leviathan with a curious passage:
And now, considering how different this doctrine is from the practice of the greatest part of the world, especially of these western parts that have received their moral learning from Rome and Athens, and how much depth of moral philosophy is required in them that have the administration of the sovereign power, I am at the point of believing this my labor as useless as the commonwealth of Plato. For he also is of opinion that it is impossible for the disorders of state and change of governments by civil war ever to be taken away till sovereigns be philosophers. But when I consider again that the science of natural justice is the only science necessary for sovereigns and their principal ministers; and that they need not be charged with the sciences mathematical, as by Plato they are, farther than by good laws to encourage men to the study of them; and that neither Plato nor any other philosopher hitherto has put into order and sufficiently or probably proved all the theorems of moral doctrine that men may learn thereby both how to govern and how to obey—I recover some hope that one time or other this writing of mine may fall into the hands of a sovereign who will consider it himself (for it is short, and I think clear) without the help of any interested or envious interpreter, and by the exercise of entire sovereignty, in protecting the public teaching of it, convert this truth of speculation into the utility of practice. (Leviathan, ch. 31; pp. 287–88)
Hobbes here suggests that the empirical adequacy of his theory depends on its successful application by a sovereign. More important, such an application of the theory requires that subjects be taught to claim their natural rights to self-preservation whenever, as subjects, they feel rightly or wrongly that their lives are in question.
Appearances to the contrary, Hobbes does not teach that subjects should be taught to be uncritically submissive and obedient; rather, the implementation of Leviathan seems to require a commonwealth in which the subjects are fully informed and aware of their rights. The presupposition of this extension is printing, and the correlative spread of reading.
Hobbes’s science is thus radically egalitarian in two senses. On the one hand, all humans have the same natural rights—and, indeed, no one could conceivably abandon the right to self-preservation, since it is the human equivalent of inertia in falling bodies (Leviathan, ch. 14; p. 112). On the other, all humans have, at least in principle, the capacity to discover scientific truths. Whereas Machiavelli asserts that political success depends on understanding inevitable differences in human intelligence,100 Hobbes claims that there is basically an “equality of ability” in matters of the “mind” as well as of the “body.”101
Machiavelli’s prudential rules for the intelligent leader become, for Hobbes, a logical tautology. The Hobbesian commonwealth is entirely manmade. And by building the commonwealth on the basis of a quasi-geometric demonstration, obedience can become a self-fulfilling prophecy (Leviathan, ch. 20; p. 170). If all subjects know and insist on the enforcement of their inalienable rights to self-preservation, sovereigns will come to encourage commerce, control monopolies, and establish a powerful government capable of effective punishment where absolutely necessary. It is, in principle, possible for humans to create an “eternal” commonwealth.
Hobbes thus replaces both ancient moral philosophy and traditional Christian teaching as the foundation of political obedience; in their place, he publishes Leviathan and encourages a sovereign read it and teach it to an entire society. Unlike Machiavelli’s Prince, which describes political things much as a painter portrays landscapes, Hobbes’s work has a constructive character in which the act of publication is itself central; for the first time, the existence of printing is consciously at the heart of a philosophic teaching.102
In his own lifetime, Machiavelli relied on the theater (Mandragola), parables (Belfagor), and the private distribution of manuscripts as the principal means of popular diffusion for his ideas.103 In contrast, Hobbes expects that the sovereign can command his book to become a printed text that rivals the Bible as the basic educational text of a society.104 Whereas Machiavelli and Leonardo were particularly influenced by the transformations in military technology introduced by artillery, Hobbes’s thought seems to have been shaped by the parallel (but slightly slower) diffusion of the transformation of communicative technology introduced by printing.
Printing is essential because Hobbes seeks to replace obedience based on the biblical teaching (”Obey the powers that be”) with his Christianized mathematical physics of human nature. When reading Leviathan, the reader himself is supposed to test the premise that the natural right to self-preservation is the principal motivation for behavior whenever individual life has been threatened (Leviathan, ch. 13; p. 107). If all members of a society were taught to do this, the political problem would be transformed into the self-fulfilling prophecy of a new political situation in which the sovereign, “authorized” by the members of the commonwealth, represents them.
This “liberal” conception of the state follows from the practical application of Hobbesian theoretical principles. All citizens have an inalienable natural right to self-preservation. Even if the government has legitimately taken steps to punish a criminal, that criminal can resist arrest or punishment by force—and in doing so, is merely following the law of nature. What is true of one citizen is true of groups of citizens. Hence the sovereign can interfere in the private lives of subjects only to the extent that the latter consent. In addition to suggesting prudential reasons for limiting state intervention in private matters, this principle shows the utility of transforming the ubiquitous competition for power into competition for economic success and wealth.
The resulting order is not merely authoritarian. While the subjects of the commonwealth are to read Leviathan, it is to be put in practice only after the sovereign has done so—and has become sufficiently convinced of the benefits of Hobbes’s theory to teach it throughout the community. And from the sovereign’s perspective, the principles outlined above required a limited government under law—or, in modern terms, a constitutional government based on the conception that the individual should be free wherever possible.
Serious interpreters as different as Jean-Jacques Rousseau, Karl Marx, Leo Strauss, Carl Schmitt, and C. B. MacPherson have therefore noted that Hobbes provides the foundations for the liberal or capitalist framework of political life which came to dominate the Anglo-Saxon nations and provided the foundation of modernity in the West. To be sure, the main features of Hobbesian theory were more effective when presented in more palatable form in Locke’s Second Treatise. Whether one considers the utilitarian thought of Bentham, John Stuart Mill, or the American constitutional tradition, however, we find the principal features of an individual rationality based on the belief in a socially constructed community in which law becomes the framework for economic progress and contentment.
While Hobbes’s theory presents itself as “secular” or this-worldly, moreover, its practical application entails a theological dimension of the greatest importance. Most readers are content to read the first two books of Leviathan, ignoring the last half of the work devoted to a “Christian commonwealth.” In seeking to avoid this error, however, it is incorrect to conclude that Hobbes’s professions of Christianity are sincere if not orthodox.105 Rather, like Machiavelli—only in a more explicit and formal manner—Hobbes transforms the Judaeo-Christian tradition, absorbing it into his reconstruction of political theory and practice through a thoroughgoing reinterpretation of the texts.
Without entering into all the details, it should suffice to contrast the way Hobbes and Machiavelli utilize the biblical texts. In The Prince, the account of Moses in Exodus is used to provide an exemplar of the entirely new prince as a human leader (see esp. ch. 6, pp. 22–23 and ch. 26, pp. 103). In Parts 3 and 4 of Leviathan, Hobbes goes to great lengths to show that his theory is consistent with the biblical texts if they are read as humanly written. Hence, in Hobbes, we can see the beginnings of what came to be known as the “higher criticism”—i.e., the use of logic to extract meaning from otherwise puzzling texts.
For example, it is imperative for Hobbes to show that the Pentateuch (Five Books of Moses) could not have been entirely written by Moses himself. To provide evidence of this interpretation, Hobbes cites the passage in which the grave of Moses is described as being unknown “to this day” (Leviathan, ch. 33; p. 54). Reading the text with usual canons of interpreting human speech, it seems logically impossible that Moses could have written a description in the past tense of the site of his own grave. Instead of using biblical texts as literal truth or testimony to divine grace (as do theologians) or as metaphor and historical source (as in Machiavelli’s Prince), Hobbes integrates the Bible into a thoroughly nominalist political teaching.
To summarize, one can describe Hobbes’s Leviathan as the foundation of a political religion. Irrational belief in biblical Christianity is replaced by a rational understanding of Christianity as an integral part of the commonwealth defined and explained in Parts 1 and 2 of Leviathan. As Rousseau put it, Hobbes was the modern writer who first sought to integrate politics and religion, creating a politico-theological teaching in which theory and practice are effectively united.106
For practical purposes, this solution entails both a tacit political establishment of religion (in the abstract) and extreme toleration of doctrinal variation. The sovereign must be the sole judge of the religious doctrines to be taught in the community. But as long as subjects do not use religious beliefs as the basis of challenging authority, prudent rulers will limit their enforcement of doctrine to narrowly defined norms which emphasize overt behavior. As in England to this day, the king can well be head of a state church in a commonwealth that encourages religious toleration.
Hobbes’s perspective can thus be viewed as a this-worldly political theology based on the fusion of theory and practice as well as the integration of natural science and political thought. The “new way” opened by Machiavelli is very greatly broadened in the process. In place of a perspective that presupposes prudence (and even wisdom) in the leader, Hobbes develops a deductive system with geometric certainty, reminds the reader that its premises can be empirically verified, and then outlines how a lasting regime can be created on the basis of these principles. That the result stands as one of the major landmarks in the history of Western political thought is confirmed well enough by the continued fascination of Hobbes’s works not to mention the relationship between his thought and the traditions of empirical research in modern social science.107
In claiming that what we call modern political theory originates in Machiavelli but is fully developed for the first time in Hobbes, I do not mean that all political theory since the Renaissance can be reduced to these two thinkers. Modernity has another variant in continental thought, epitomized by the tradition stemming from Descartes and developed further by Montesquieu, Rousseau, Kant, Hegel, and Marx. In the Discourse on Method and Rules for the Direction of the Mind, Hobbes’s French contemporary showed a rather different method of integrating the new, mathematical sciences of nature with the study of humans; as set forth in the Meditations, to which Descartes appended the Objections of Hobbes (among others), the differences between this approach and that of Leviathan become explicit.
In a fuller account, it would be necessary to spell out in more detail the variants of what has here been called modernity. For the moment, however, it should suffice to indicate the central traits of fully developed modernity as they are developed by Hobbes and can be seen in subsequent thinkers whose approach to theory and practice can be called “modern.” Whatever the differences between Hobbes and thinkers in the Anglo-Saxon tradition from Locke to John Stuart Mill, not to mention the parallel continental tradition from Descartes to Marx, several common characteristics can be traced. By summarizing these traits, we can gain a better view of our own situation.
Rational or scientific knowledge of nature can, in principle, explain all things in a manner comprehensible to all. To do so, science must abandon the claim of knowing the essence or purpose of things and limit itself to explaining their movements and changes. In such a science, theories take a hypothetical-deductive form, in which mathematical representations of nature are accepted only insofar as experiments confirm them.
In modern science, concepts therefore need to be defined explicitly so that they will be logically consistent and empirically relevant: “Let x equal. . . .” Explanations need to be couched in hypothetical manner so that any trained scientist can produce the predicted effects: “If x, then y.” Scientific theories are therefore constructive insofar as they take the form of rules or instructions that permit the observer to reproduce visible things in principle if not in practice.
To know something, therefore, is to know how to “make” it—even if the construction is theoretical.108 Such a natural science continually gives rise to technologies that control or redirect natural necessity. In turn, these technologies permit an ever-increasing extension of scientific theories to explain things too distant, too minute, or too complex for naïve observation. Theories therefore have practical applications, and practice is the test of theoretical knowledge.
Because humans are natural things, modern science can focus on social or political things as well as on inanimate or animate nature. Since the hypothetical-deductive method cannot derive primary terms from experience or custom, political or social theories approach human behavior from an objective standpoint (as if the theorist were outside society much as a watchmaker is outside the watch being made or repaired). This perspective makes possible theories claiming to explain the motive forces and history of human affairs, but not the best way for an individual to live.
The result is a paradox. Although a thoroughly modern science cannot claim to know the essence or goal of human life, its theories can and should guide practice. Prior to the Renaissance, such practical guidance was, in part, sought in religious doctrine and belief. Hence science, while focusing on the visible world and the material experience of humans, necessarily has theological implications.
If modern science can explain all things, it can change things: theories in the natural sciences are the foundation of technology. If science and technology can change or control things, humans can replace prayer to God or the gods by activity using power in the quest for desired outcomes. Because science, technology, and their practical fruits claim to be understandable to all humans, scientific theories of human society can be the foundation of systems of belief. The scientific temperament provides satisfactions on earth in place of otherworldly faith—but in politics, the success of this endeavor entails the transformation of political philosophy into political religions or ideologies.
Before the emergence of such political religions or ideologies, political leadership entailed prudence or good judgment. Only some individuals, endowed with talent and educated to achieve their natural potential, were capable of effective rulership. Modernity, by ushering in the age of ideology, points to the replacement of prudence by a science of public policy. The design of effective “development” or progress is thus made possible by a combination of technical expertise among the elite and political belief among the citizenry. At most, there is disagreement concerning the advisability of public controversy concerning policy proposals and belief systems: for modern “liberals” and “democrats,” regimes must be open or free, whereas in the authoritarian versions of modernity, public debate concerning policies and principles is a luxury that cannot be tolerated.
Whatever other differences are found within the Anglo-Saxon and continental traditions of modernity, this epoch of history represents an attempt to integrate theory and practice, science and belief, religion and human affairs, national patriotism and the interests of the human species as a whole. It remains to be seen, however, whether this attempt is feasible. The failure of Marxism and the eruptions of violent nationalism, racism, and religious fundamentalism both within and outside the West, which mark the last years of the twentieth century, suggest that the modern epoch may be approaching its end.
Today, many have recognized this “exhaustion of the West” by speaking of post-modernism. Those who use this term often seem to espouse a highly relativist or subjective view of knowledge, attributing established modes of thought to the social forces that are dominant in our society. The foregoing exploration of the origins of modernity suggests a rather different set of questions. Most of the traits here associated with the modern epoch are shared by post-modernists. As we witness the collapse of global communism, the emergence of nationalistic irredentism, and the resurgence of religious enthusiasm, the expressions of post-modernism appear as one version of modernity rather than a true challenge to its fundamental assumptions.
Looking ahead to the twenty-first century, the technological and practical dreams of Leonardo and Bacon now appear to be within reach. It seems but a matter of time until techniques of in vitro fertilization and intensive neonatal care are merged to permit industrialized production of human beings.109 The advances in the human genome project, molecular genetics, and neuroscience—not to mention technologies from supercomputers and fiber optics to genetic engineering, nitrogen-fixing plants, and other technological revolutions—loom on the horizon precisely at a time when many have become deeply skeptical of science and the modern project itself.
The issue can be put simply. Soon, Brave New World will be technologically feasible: institutions introduced as comic impossibilities in Plato’s Republic and as horrible dystopia in Huxley’s novel are likely to become practicable in coming generations. For the first time since the opening of a new epoch of Western thought by Machiavelli, Leonardo, and Hobbes, we need to question whether our civilization should return to the horizon that these early moderns sought to transcend. Put in nutshell, can theory be a complete guide to practice? If not, should we return to the ancient view that human politics is ultimately limited by what is just according to nature?