A Review of “Science and Change 1500-1700” by Hugh Kearney

We take modern science for granted, and assume that it has always been the way that it is today, with professional scientists, empirically-based research, peer-reviewed journals, laboratories, and a common scientific method accepted by all. But what we know as science today evolved over time. In the Middle Ages there were monks in monasteries studying “natural philosophy,” and alchemists doing chemical experiments, but no scientists in the modern sense. During the early modern period, something happened to transform natural philosophy and alchemy to science. Hugh Kearney discusses this crucial transition period, aka “The Scientific Revolution,” in his book Science and Change 1500-1700.

This book, originally published in 1971, is an old college textbook of mine that I decided to reread recently. It includes many fascinating images, reproductions of paintings, drawings, and diagrams that are relevant to the text discussion. The prose is clear and straightforward, and it includes a wealth of historical examples. The book’s theme is that the Scientific Revolution can be understood as a mixture of three intellectual traditions: organic, magical, and mechanistic. Each tradition had roots in ancient Greek philosophy. During the Middle Ages, the ancient texts were rediscovered and merged with Christian theology, becoming a new establishment, known as “scholasticism”. The Scientific Revolution was largely a revolt against this establishment, favoring empirical research over reliance on ancient authorities.

The organic tradition was based on what we now call biology, with the emphasis on study of living organisms. The Greek philosophers who most influenced men working in this tradition were Aristotle and Galen. Aristotle’s philosophy was wide ranging, but his empirical observations most influenced people working in the organic tradition. Galen, who came after Aristotle, was best known for his anatomical and medical work.

The University of Padua was the capital of the organic tradition during the Scientific Revolution. Some famous names of faculty members there include Andreas Vesalius (1514-64), the “father of modern anatomy,” and Gabriele Fallopio (1523-63), who discovered the Fallopian tubes. William Harvey (1578-1657), who discovered the circulation of blood, was a student at Padua.

The magical tradition provided a scientific framework in which nature was seen as a work of art. God was thought of as a magician or artist, and mathematics was a tool to understand the Deity. The Greek philosopher who most influenced this movement was Plato. His ideas were taken up and modified by the Roman philosopher Plotinus, who founded a movement called “neo-Platonism.” Also influential in this movement were writings attributed to a legendary Egyptian named Hermes Trismegistus, along with the Jewish Cabbala.

Some famous men in the history of astronomy were influenced by the magical tradition. Nicholas Copernicus (1473-1543), who was influenced by neo-Platonism while living ten years in Italy, developed a mathematical heliocentric theory. Tycho Brahe (1546-1601), who was influenced by astrology, made a large number of astronomical observations. Johannes Kepler (1571-1630) made use of these observations to argue that planets move in elliptical orbits around the sun, and that the velocities of the planets are not uniform during the course of their orbits. Kepler utilized the magnetic theory of English physician William Gilbert (1540-1603) to explain planetary motion in terms of magnetic interactions. Kepler’s last book was a mass of neo-Platonic speculation. Isaac Newton (1642-1727), the discoverer of the universal law of gravitation, was in part a neo-Platonic mystic. He looked upon space and time as part of the Divine presence in the universe.

The mechanistic tradition viewed nature as a machine. Natural phenomena were regular and predictable, capable of being understood by mathematical laws. Greek philosophers in this tradition included Democritus (an early atomist) and Archimedes (a mathematician and engineer).

Some famous names in physics, chemistry and applied mathematics were part of the mechanistic tradition. Galileo (1564-1642) developed laws of motion based on experiment. He contradicted Aristotelian doctrine by showing that the speed of a falling body is not proportional to weight. Mathematician and philosopher René Descartes (1596-1650) helped promote the mechanistic world view. Descartes’ philosophy conflicted at almost every point with Aristotelian principles, but his extensive use of deductive reasoning left him as exposed to experimental attack as any of the scholastics. Mathematician, experimenter, and philosopher Blaise Pascal (1623-62), who invented a primitive calculator, saw no trace of the Christian God in the world of nature. According to Pascal, God sometimes intervened miraculously, but didn’t interfere with the mechanical laws of nature. Pascal attacked the Aristotelian assumption that the vacuum doesn’t exist by doing a series of experiments. Robert Boyle (1627-91) applied mechanical philosophy to the world of chemistry. He formulated the law that pressure is inversely proportional to volume. Isaac Newton was in part a mechanist, especially in his optical work, which showed that light behaved according to mechanical laws when passed through different media.

What tradition won out in the end? For science, the mechanistic tradition became dominant. Physics and chemistry became the models by which all sciences were evaluated. Modern astronomy, which started with the neo-Platonic speculations of Copernicus and Kepler, eventually shed its mystical/astrological side and became a sub-discipline of physics. Even biology, which began in the Aristotelian/organic tradition, over time became mechanical. Darwin’s theory of evolution did away with the need for postulating Aristotelian final causes to explain higher organisms. Natural selection, not God’s will, explains how humans evolved from primitive ancestors. Cells, tissues, and organs became to be viewed as biochemical factories, randomly designed from a genetic blueprint.

For society as a whole, the mechanistic philosophy became most influential in the late 17th and 18th centuries. The philosophies of Descartes, Spinoza, Hobbes, Locke, Voltaire, Adam Smith, and the American and French revolutionaries were squarely in the mechanistic tradition. The Scientific Revolution influenced the early stages of the Industrial Revolution. For example, James Watt, inventor of the steam engine, was acquainted with scientist Joseph Black, who did work on latent heat. The neo-classical revival of the Age of Enlightenment was influenced by the mechanistic tradition. Clear and concise prose, such as that of John Locke, became a model for many others. Poetic satire such as Pope’s Dunciad replaced poetry based on magical and mystical sources of language and imagery. Neoclassical art, such as that of David, emphasized clarity and simplicity.

The Romantic movement that began in the late 18th century turned against the mechanistic/scientific viewpoint. It influenced philosophy, art, music, politics, and culture. Gradually, romanticism was replaced by realism and then modernism and post-modernism. While these subsequent movements revolted against previous movements, and had unique characteristics, none of them revived the mechanistic philosophy. This has led to a division between mechanistic scientists, engineers, technicians, doctors, lawyers, and other practical people, versus artistic, creative, philosophical, religious, spiritual, and other non-practical people, a divide that persists across the world today. This division is also present in most people, with a practical, mechanical side and a non-practical, spiritual side, with usually one side being dominant.

One criticism of Kearney’s thesis of the different traditions is that he may have emphasized too much the non-scientific views and philosophies of some of the early scientists. While Harvey was influenced by the organic philosophy of Aristotle and Galen, and Copernicus, Kepler, and Newton by neo-Platonism, are these influences essential in understanding their scientific achievements? These men are famous today because they made some discovery that influenced the future direction of science. Their discoveries came not from their philosophical and religious influences, but in spite of them. They applied the scientific method to refute some ancient authority or commonly-held belief. For example, is the fact that Kepler believed in neo-Platonism, but Galileo did not, reason enough to separate them into different traditions? They were both natural scientists who made important discoveries, discoveries that relied on observation, data, and mathematics. Are their religious or philosophical beliefs essential to understanding their contribution to science?

I recommend “Science and Change 1500-1700” to anyone interested in the history of science.