Scientific Revolutions and the Humanistic Study of Science

Compared with their modern-day counterparts, scientists and philosophers in Christian Europe during the Middle Ages had a relatively simple job. They adhered to a view of the cosmos in which an imperfect earth sat immobile, surrounded by the precisely rotating, crystalline spheres of the heavens--the moon, planets, sun, and stars, all perfectly formed and unchanging. These scholars' concept of the universe, advanced by ancient Greeks including Ptolemy (100-170 A.D.) and Aristotle (384-322 B.C.), corresponded nicely with Christian-ity, the overarching belief system of that time and place.

Science and philosophy in that era could both be part of the same world-view because they had a common basis in Christian faith, according to Michael L. Friedman, the Ruth N. Halls Chair Professor of History and Philosophy of Science and of Philosophy. "A progression toward perfection would be to go from earth to the heavens, and in fact the idea existed that beyond the outermost spheres of the universe was God. The perceived structure of the universe mirrored the Christian ideas about heaven and earth," Friedman says.

The great scientific revolution of the sixteenth and seventeenth centuries caused an irreversible split, however, between religious faith and science. This revolution was ushered in by Nicolaus Copernicus (1473-1543) and Galileo Galilei (1564-1642), who described a radically different version of the universe, one in which the earth came to be seen, Friedman says, as "just a little speck of matter moving around the sun, with the sun moving around in the Milky Way. There was no longer the idea of perfection; there was just matter moving around according to the mechanical laws of motion."

Out of this "Copernican revolution" modern philosophy was born, says Friedman. "The philosophers rejected Aristotle. They didn't reject Christianity, but they rejected the idea that philosophy should fit with Christianity as it had during the Middle Ages." This secularized form of Western philosophy reached its pinnacle in the eighteenth century with the Enlightenment. One of the greatest figures in philosophy from that period was the German Immanuel Kant (1724-1804). Perhaps best known for his masterpiece, the Critique of Pure Reason, Kant spent his life immersed in the study of those sciences thought to be most closely associated with rationality: geometry (which in the 1700s relied on the theories of the ancient Greek mathematician Euclid) and physics as conceived by the English scientist Sir Isaac Newton (1642-1726).

"Kant developed his philosophy to a large extent in order to accommodate and explain the success of Newtonian physics," Friedman says. "A view that developed under the rubric of Modernism during the Enlightenment was that modern science, which was able to give a unified description of the universe on a mathematical- mechanical model, should somehow replace religion--or more generally, that human reason, as exemplified by science, should become the new foundation for our shared culture and values." His desire to promote this shift of emphasis from religion to reason led Kant to write Religion within the Limits of Reason Alone. Friedman says, "Kant tried, starting from purely rational ideas, to give an interpretation of Christianity based not on faith but on reason."

Kant believed that Euclidean geometry and Newtonian physics necessarily described how the natural world works because they also describe how the human mind works. "Two important categories of the mind for Kant were space and time, which he thought were not out in the world but somehow in our minds," Friedman says. "He thought that everything we perceive in space has to be subject to the laws of Euclidean geometry because Euclidean geometry is somehow built into the human cognitive apparatus."

The Newtonian-Kantian view of the natural world, however, was destined to be overthrown, like the Ptolemaic-Aristotelian view before it, in a new scientific revolution. This revolution occurred in the early twentieth century, sparked by Albert Einstein's (1879-1955) articulation of the theory of relativity. Unlike previous universal physical theories, the theory of relativity is based on the concepts of non- Euclidean geometry--which European mathematicians had developed in the nineteenth century--and on the idea of relative motion, unlike the absolute motion proposed by Newton's theory of mechanics.

Despite Kant's association with theories that have now been superseded, he remains, according to Friedman, "the most important philosopher of the modern period." In his 1992 book, Kant and the Exact Sciences, Friedman analyzes Kant's contributions within the context of eighteenth-century scientific knowledge. "His philosophy was extraordinarily insightful in terms of the science of his time, and that's why it's so important, not because it's 'true' now. In particular, the way both science and philosophy have changed since the time of Kant and Newton illuminates tremendously our current intellectual predicament," Friedman says. Friedman became interested in these larger issues of the history of Western scientific thought after the publication of his earlier book, Foundations of Space- Time Theories, a study that examines the structure of the theory of relativity and compares it with Newtonian theory. The book also addresses the influence of relativity theory on a group of twentieth-century philosophers known as the logical positivists. Inspired by the advances in physical science in the first decades of this century, the logical positivists rejected the study of "metaphysical" philosophical topics--such as ethics, philosophy of religion, and aesthetics--in favor of clarification and analysis. They aimed to turn philosophy itself into a science by restricting it to the logical analysis of scientific language.

Friedman thus began enlarging his own inquiry, considering the evolutionary path of philosophy from the Enlightenment to the 1920s. "Kant had a certain view of science and a philosophy based on Newton. The positivists had a certain view of science and a philosophy based on Einstein," he says. "I'm interested in understanding how these things changed, the progression. I believe that we can not really understand our situation now unless we understand how we got here."

Our current intellectual predicament was best articulated, Friedman says, in the work of Thomas Kuhn, author of the groundbreaking 1962 book The Structure of Scientific Revolutions. "Scientific revolutions are one of the most interesting topics in the field of history and philosophy of science. Kuhn said that in a scientific revolution, when a truly radical change occurs, for example, from Newtonian physics to relativity theory, the change cannot be thought of as a purely rational change. In that instance there was no common geometry serving as a basis for reasoning that remained constant. Concepts in relativity theory, such as its concepts of space or time or mass or length, just can't be translated into classical physics," Friedman says. "Because there are two sets of concepts that can't be translated into each other, we can't think of the change from one to the other as the outcome of a rational argument. Kuhn says it's more like a conversion." Thus to understand the profound philosophical consequences of of relativity theory--beyond its impact among physicists--Friedman delved ever deeper into the challenges to rationalism and objectivity that have arisen in the aftermath of logical positivism.

Kuhn's work supports the idea that a "crisis of objectivity" has prevailed since scientists embraced the theory of relativity. "During the Enlightenment, science became the paradigm of whatever seemed objective, of whatever people could agree on, regardless of their differences, even their religious differences. Kant's philosophy explained that construction of 'objectivity,' for example, by saying that certain spatiotemporal ideas such as geometry are innate to all human beings. But by demonstrating the limitations of Euclidean geometry, relativity theory threw a monkey wrench into that philosophy," Friedman says. "It showed that geometry seems to be historically contingent. Geometry isn't true for all time." So more doubt now exists, Friedman says, about whether any scientific facts can be considered truly objective or immutable.

Our current "crisis of objectivity" is also connected to the realization that rationality, so prized from the Enlightenment through the era of the logical positivists, does not serve as a sufficient restraint on the technology unleashed by scientific knowledge. "In the eighteenth century, people had faith that the rationality of the scientist would in a way take the place of ethics, and give us values," Friedman says. "But the destructive uses of science--for example, the use of technology in warfare--show us that it doesn't work that way. There's nothing inherent in science that forces it to be used for good ends, and in fact, the powers of technology can destroy the world. After all, it was Einstein's well-known formula, E = mc2, that made it possible to develop atomic weapons."

It is no coincidence, then, that academic programs devoted to scrutinizing science from a humanistic perspective emerged in the years after World War II. Only since that period has history and philosophy of science been recognized as a separate intellectual discipline. This discipline emerged in the United States around 1960, the time when Norwood Russell Hanson founded the Department of History and Philosophy of Science at IU, and when similar programs were developing throughout the nation.

The reason for this movement to reevaluate the role of science was that "we could no longer be so naive," Friedman says. "We could no longer say that if we follow science, everything will be all right. We can't just let science go along; we have to independently form an idea of what our values are, and then we have to use them to control how science is used. We in the humanities, who are concerned with values, should study science." The increasing codependency of science and the humanities is as urgent a public and scholarly issue as it has ever been. Ruth Halls' bequest and the selection of Michael L. Friedman as the first Halls chair in the humanities help Indiana University to retain its leadership role in one of the most important debates of our time.

--Karen Grooms