origin of Descartes' mechanical philosophy, The

Georgia Journal of Science, 2002 by McMullen, Emerson Thomas

ABSTRACT

Rene Descartes' concept of a mechanical universe included the idea that organisms are machines. He reasoned that even though humans possess an immaterial soul, it still resides in a mechanical body. However, a living organism is different from a machine: Bodies develop and grow machines don't; living organisms reproduce - machines don't; bodily wounds heal - machine damage doesn't. So how did Descartes decide to equate living organisms with machines? A number of explanations have been proposed, but none of these include Descartes' early military career. In 1618, Descartes joined the Dutch army as a gentleman volunteer. There he was introduced to the world of the military engineer and to the ongoing mathematization of the art of war. He also learned the new and extensive training the army went through in order to load and discharge their firearms and maneuver with them. One unintended result of all this training was that the soldiers, acting and drilling in unison, started to behave like automata. In other words, a group of organisms behaved in a machine-like manner. This concrete demonstration of a previously more abstract mechanistic concept, which he discovered in a mathematical and engineering setting, may have been the inspiration for Descartes' idea that human and animal bodies are like machines, in spite of many dissimilarities.

Key Words: Descartes, mechanical philosophy, automata, machines, Dutch army.

INTRODUCTION

The twentieth-century interaction between science and the military is well known. The prime example is the development of the atom bomb. In spite of Galileo's activity in this area, the growing interaction between science and the military in the sixteenth and seventeenth centuries is not as well known. Galileo taught private courses on military architecture and fortification, developed the geometric and military compass (1), and planned to initially market his telescope to the military. This article discusses the possibility that Rene Descartes' mechanical philosophy was influenced by his early career in the military.

A New Philosophy of Nature

An influential worldview that emerged from the Scientific Revolution likened the universe to a machine. This mechanical view of the universe can be traced back to the Greek atomists, but due to the dominance of Aristotelianism, it never entered mainstream scientific thought until the seventeenth century. A key figure in the promotion of the mechanical philosophy was Rene Descartes (1596-1650). Among other things, he thought that the human body and animals (beasts) were machines. However, a living organism is different from a machine, so why did Descartes decide to equate living organisms with machines? Several answers have been argued - one is that Descartes viewed God as a master mechanician. My thesis is that while Descartes was aware of mechanisms in an abstract way, the new military discipline of his day was a concrete demonstration to him that human and animal bodies can be thought of as machines. I agree that there had to have been many casual factors regarding the origin of mechanical philosophy, but the "Dutch drill" appears to be the only one at the biological level. Also to be added to these causal factors are the military engineering and mathematization of war that he learned in Holland.

The first step in the introduction of a new idea, such as the mechanical philosophy, is the rejection of the old one, in this case, Aristotelianism (2). Although the momentum of the Aristotelian tradition carried it into the seventeenth century (3), it had been discredited in the minds of many thinkers by that time. One reason was the Reformers' attack on portions of Aristotle's thought, especially his Ethics, which Martin Luther proclaimed was "the worst enemy of grace" (4). Other reasons were challenges from older philosophies revived during the Renaissance recovery of ancient texts; these included Pythagorean, Platonic, Stoic, Epicurean, and Hermetic thought (5). Similarly, there were challenges from new philosophies: Paracelsus promoted three principles to replace Aristotle's elements, and William Gilbert proposed a new philosophy based on magnetism (which Kepler used to explain planetary attraction to the sun) (6). Archimedes' works, important for the mechanical philosophy, were revived and developed (7). The skeptical crisis growing out of the Reformation challenged contemporary thought concerning the basis of truth, while the publication of the classical skeptical literature fueled this crisis (8). The astronomical revolution was not just Copernicus and Kepler making the earth a planet, and thereby destroying Aristotle's physics; it also included Tycho Brahe's measurements of the new star of 1572 and the comet of 1577, which showed that Aristotelian cosmology was wrong (9). The time was ripe for a new philosophy of nature, but what would it be?

Is The Universe a Machine?

A Frenchman who lived just before Descartes, Henri de Monantheuil, stated the basic and Biblical argument of his day for considering the universe as a machine: Since man is a mechanician (a person skilled in the design, construction, operation, care of machines), and because God made man in His image (Genesis 1:26), therefore God is a Mechanician. It follows that, since mankind designs and constructs intricate machines like clocks, then God, who is greater than mankind, made the universe a vast and highly complex machine (10).