Graziano & Raulin
Research Methods (9th edition)
Isaac Newton (1642-1727) was an English mathematician and philosopher.
Kepler had died twelve years before Newton’s birth, and his work was an important basis for Newton’s monumental work on the laws of gravitation. Newton’s philosophical background was heavily influenced by Descartes’s mechanistic and mathematical conception of the universe. Newton was one of a long progression of scientists who overturned medieval theological approaches to science, brought about the emergence of modern science, and defined the 17th and 18th centuries as those of the “vast machine” philosophy.
To understand the emergence of modern science and Newton’s place in it, we need to consider medieval thinking, which had dominated western philosophy prior to the renaissance. Medieval thinking was, essentially, theological. It was a sophisticated, rationalistic approach to the hierarchical arrangement of all things and events in the universe. A basic premise of this perspective was that a perfect God had created the universe, and all beings, events, and objects shared, in hierarchical order, some degree of that perfection. God, the one perfect being, is at the top of the hierarchy. Any category of things and events can be organized through logic into the inherent hierarchy. For example, one such hierarchy would have God at the top and, in descending order, angels, man, animals, plants, and minerals. Likewise, such physical bodies as planets and stars and their motion through the skies can be arranged hierarchically. Those in the heavens--celestial bodies--are the more perfect; they are circular in shape, move through circular paths, and their forms and motions are uniform and stable. (Here we see the continued influence of the Pythagoreans, Socrates, and Plato). Terrestrial (earthly) bodies, however, are farther from perfection. They vary in shape, their motions are irregular and linear rather than uniform and circular, and they are constantly changing. Thus, there is a qualitative differences between celestial events and terrestrial events. This concept established a clear distinction that carried through to Newton--specifically, the principles that celestial motion is different from terrestrial motion.
For our discussion the following points about medieval theology are important:
- A major goal in theological understanding of the universe was to correctly locate any object or event in that divine hierarchy;
- The means for doing this were rational and logical, employing syllogistic arguments (as discussed in Chapter 1).
- In this rationalistic process, there is no need for quantification or experimentation.
Theological thinking was dominant in Western Europe. However, there was also a long thread of empirical science dating from the Ionian philosophers in 600 B.C. (see Section II, Early Science, in this historical section of the website). Many events of the 12th and 13th Centuries reinforced those empirical alternatives, which by the 17th and 18th Centuries, had become the dominant science. Two of those factors were the growth of world trade and urbanization. For example, no matter how devoted commercial people were to their Christianity, there were times when the demands of commerce forced them to compromise their religious faith. Furthermore, population growth and urbanization forced people to solve pressing practical problems, which took time away from considering the proper order of things in the celestial universe.
One of the major revolutions in science occurred in astronomy, with powerful implications for the new conceptualization of a mechanistic and mathematical science. After 1300 years, the Copernican heliocentric model finally supplanted Ptolemy’s geocentric model of the universe in the 15th Century. This, in turn, stimulated astronomers, such as Tycho Brahe (1546-1601) and one of his assistants, Johannes Kepler. Brahe and Kepler dramatically improved astronomical observation. Both were careful observers and excellent mathematicians.
Kepler, in particular, was painstaking in his deductions from mathematically based hypotheses, followed by verification with empirical (astronomical) observation. Their work strengthened the use of mathematical reasoning and empirical observation in science and, as a result, weakened the theological cosmology, with its dismissal of mathematics and empiricism.
Galileo’s telescopic observations provided strong support to the Copernican model and further eroded the theological view. Galileo observed that the moon was not a perfect sphere, but a sphere with an irregular surface. It has mountains (whose heights he calculated by observing their shadows), valleys, craters, and plains, much like the earth. He saw that the sun had blemishes on its surface, and that Jupiter had four moons orbiting around it, thus providing a small-scale model of the solar system. Galileo virtually destroyed the theological notions of the “perfection” of the forms of heavenly bodies and that celestial objects are qualitatively different from terrestrial objects. He further reinforced the power of empirical observation.
Those developments led to the finalization of Descartes’s wish for a mechanical/mathematical model of the universe and definition of science, and it was Newton who brought it together. Newton integrated the work of his predecessors and added his own significant creative contributions. He defined science as the application of mathematics to the study of natural phenomena, coupled with empirical experimentation. With this approach, he created a unified system for astronomy and physics, defined modern science, and laid to rest the powerful theological cosmology. Newton’s book Philosophiae Naturalis, Principia Mathematica (1687, see Newton 1999) was enormously influential, even in his lifetime, and it is one of the world’s greatest scientific achievements.
The Newtonian conception of the universe was that of a vast machine, created by God. That machine runs in an orderly and predictable manner and can be studied and understood by mathematical and experimental means. The 18th Century was dominated by Newton’s concepts, and has been called the “Newtonian Age” and the “Age of Reason.”
We should note that in the next century, as often occurs in history, there was a major retreat from the principles that defined the Age of Reason. The mechanistic and mathematical view of reality of that period was replaced by the Romantic Protest movement. This movement will be discussed briefly in the next section on Nineteenth Century Science and Technology.