Newtonianism and the Enlightenment

Benjamin O’Connor

STS-003 Paper assignment #1

Newtonianism and the Enlightenment

In the subjects and quandaries that Isaac Newton dealt with, he left a good deal of work unfinished. Certain holes remained – undiscovered suggestions left as a challenge for the future natural philosophers of the Enlightenment and beyond. For example, Newton never was able to assign a cause for gravitation. In discovering the causes and effects of the natural world Newton, as well as other natural philosophers of the time, hoped for science to come upon a “first cause” and hence a general, moral science. He expounded upon this in one of his latter works, “Optiks”:

“And if natural philosophy in all its Parts, by pursuing this Methods, shall at length be perfected, the Bounds of Moral Philosophy will also be enlarged. For so far as we can know by natural Philosophy what is the first Cause, what Power he has over us, and what Benefits we receive from him, so far our Duty towards him, as well as that towards one another, will appear to us by the Light of Nature”

This Newtonian search for a “first cause” through natural philosophy and scientific work laid the groundwork for the great scientific revolutions and discoveries during the Enlightenment. Exactly what “first cause” the natural philosophers of the enlightenment were working towards was a serious point of disagreement. Some, taking Descartes view, believed that there were no forces innately in matter and that God created the universe as a clockwork mechanism that has functioned thereafter without intervention. Others took the philosophy of pantheism, for the belief that God and the laws of nature were one and the same. Still others, such as Denis Diderot, believed that nature and reason were sufficient by themselves, and denied the existence of any spiritual God. No matter what the moral and spiritual philosophies were behind it, Newtonianism inspired all natural philosophers to theorize and experiment, launching the scientific revolution of the Enlightenment.

It was Newton’s idea of a quest for moral science through natural philosophy that became the theme of the Enlightenment and inspired those who came after him. While Newtonianism may have been an inspiration, others certainly did not all agree on Newton’s spiritual views and the place of this “first cause.” During the Enlightenment, natural philosophy still struggled with philosophical questions such as the activity of matter and the origins of force and motion in matter as well as the existence of a soul and free will. Whether matter was moved by an external power, an internal power or by no power at all was a fact disagreed on by philosophers of the time. Descartes saw the universe as clockwork, with all matter in motion and collision constantly. Malebranche believed that all force originated not through matter and collisions, but by the power of God, with collisions being merely opportunities for divine intervention. Leibniz argued that forces were actually a part of matter: “If one divides matter finely enough, one must come to something that is no longer matter, and these nonmaterial metaphysical entities are the sources of the power and direction that we observe in the world.” (Hankins, 14) Newton built his mechanics from the assumption that there are forces in matter and its particles. However, he did not believe in innate forces or powers such as the “divine intervention” that Malebranche speaks of.

As the spirit of Newtonianism gave rise to thoughts and theories concerning the origins of force and man’s place in the universe, it also contributed to theories of general moral philosophy. Deists took Newton’s argument that moral philosophy follows from the bounds of natural philosophy as proof of the existence of God. Pantheists saw Newtonianism and natural philosophy as a way to equate God to nature, with all of its rules and reasonable order. Still others took the Atheist point of view and saw nature and Newtonianism as a replacement for a spiritual God, believing that science and natural philosophy could explain everything.

We can clearly see that while the spirit of Newtonianism led both moral and natural philosophy to be closely examined during the Enlightenment, it certainly did not dictate the specific beliefs or methods of this experimentation and theorizing. The quest for a “first cause” was well underway, and everyone had a view, theory, or school of belief to subscribe to. To these people, Newtonianism was a spirit of wide-eyed curiosity about the workings of our universe, and a genuine desire to understand its most intricate inner-workings and cause-effect relationships.

Newtonianism also had an alternate meaning, with slightly different results and goals. Through Newton’s groundbreaking work in the field of what we would now call classical physics, he inspired natural philosophy to explore questions of the nature of the universe and of matter and motion. Much research and many ideas spawned directly or indirectly from Newton’s ideas. Work was done from what he understood, as well as those questions that remained to be answered. One notable example of this was the theory of the calculus and of integrals as discovered by Leibniz. Plagiarism or not, it was Newton’s work on the subject and its applications to mechanics and the behavior of matter and the universe that inspired Leibniz to work on the subject and eventually publish it before Newton. This curiosity is exemplified by a challenge to Newton’s theory, put forth in the Principia, that because of the earth’s rotational force, it’s equatorial diameter would be greater than the diameter measured through its poles. Various measurements from the French, however seemed to contradict this theory. Expeditions were immediately sent out to the polar and equatorial regions to measure lengths of latitude. Indeed, in accordance with Newton’s theory, a degree of latitude in the arctic region was longer than one taken in the equatorial region.

Newton’s queries, left for posterity in his Optiks, were an example of Newton’s humble empiricism and quest for the truths of natural philosophy. These queries spanned many fields of science, including more than what we would call physics today. He posed questions about not only the origin and methods of light and gravitation, but also of various chemical properties as well as biological and psychological quandaries. From here, we can see many other fields evolving and taking on their own meanings for “Newtonianism.” It leads us to wonder, did pioneering chemists such as Antoine Lavoisier and Joseph Priestly think themselves “Newtonian?” Quite possibly, they did identify with Newton and his spirit of humble empiricism. Many scientists of the Enlightenment and thereafter, were following in Newton’s footsteps, and working in the tradition of the Principia:

The Newtonian experimental tradition as pursued by Hales and by the very many eighteenth-century electricians from Stephen Gray onwards, was one of course perfectly sound, and produced innumerable notable discoveries… (Hall 358)

A multitude of other experiments and endeavors to define behavior of all systems in our universe were also launched directly or indirectly from Newton’s queries. Nature was indeed knowable, and the spirit of Newtonianism would drive scientists in all fields on their quest for knowledge.

Many other natural philosophers had ideas spawned from Newton’s voluminous research and literature. Newton’s brief hinting of an all-encompassing “ether” or ever-present essence, subtler than air, became a belief held for generations, although it turned out to be quite false. Natural philosophers of the Enlightenment and beyond strove to further elucidate Newton’s ideas, and come up with their own ideas for what Newton left undiscovered. Other philosophers’ works added to Newton’s discoveries and answered his unanswered questions posed in the Optiks, his legacy for Enlightenment science. One scientific riddle of importance was that of the motions of the planets. Newton had solved it, and others, like Edmund Halley, expanded upon it. It was obvious that for natural philosophy to move forward, people would work on Newton’s program of research. Natural philosophers would use his methods and circulate his ideas. Work was compounded into one scientific body, constantly adding up, rather than contradicting:

Natural Philosophy had one advantage over other literary pursuits: it progresses. When the literary world quarreled over whether ancient or modern literature was superior, the moderns inevitably pointed to philosophy. In natural philosophy the truths were more obviously cumulative. The seventeenth-century philosophers knew what the ancients knew and added to them the truths that had been discovered in more recent times. (Hankins 8)

This was the real spirit and meaning of Newtonianism that most natural philosophers of the time agreed to and identified with. If there was a riddle to be solved, it could be done with reason. The body of work that Newton had created would be used as a foundation for all Enlightenment science. It would indeed prove to be the foundation of a scientific revolution. Theories of not only physics, but chemistry, electricity and magnetism grew out of Newton’s humble empiricism.

Newtonianism meant different things to just about any natural philosopher of the Enlightenment. However, the Newtonian spirit inspired the scientists and natural philosophers of the Enlightenment. Newtonianism was an inspiration for them to explore the mechanisms of our universe. The cause and effect relationships discovered in our world would eventually distill down to a “first cause.” This is what the science of the Enlightenment was about – the quest of knowledge for the betterment of man. Even though people disagreed, sometimes bitterly, about what this “first cause” was, and what role it played in the forces governing the motion of the universe, they were all looking for it. Careful observation and a humble empiricism was the Newtonian method of finding these cause and effect relationships. These philosophers of the Enlightenment strove towards something concrete, “…a real, ordered natural creation, independent of man but rationally knowable by man so that its properties and laws could be discovered." Hall 360) Newtonianism was a wide-eyed curiosity shared by the natural philosophers of the Enlightenment -- not knowing what lay ahead, but eager to discover it in a rational way. It is because of this individuality that Newtonianism can not be simply categorized as a parallel to Bacon’s philosophies or even the rational Descartes’ school of thought. Newtonianism was a unique attitude, not necessarily a philosophy. It was a fundamental change in man’s attitude to the world around him, which led him to abandon old traditions and beliefs, and seek out the true underlying mechanisms of nature. This fundamental change permeated the Enlightenment and is still at work in science today. We strive to understand that which makes the universe work. We strive to understand how we can make nature, and human society work to our advantage.