When Newton's Principia appeared in 1687, England had been embroiled in a seemingly unending
period of religious and civil strife. The country was exhausted intellectually as well as physically from the clouded and passionate issues that had set Catholics against Protestants, monarchists against republicans. In this atmosphere seething with discontent, Newton's worldview was welcome, not only as a monumental intellectual feat but also as refreshingly detached from the subtle and complex disputes of theology and politics.
To the world Newton appeared to have discovered not simply a way of understanding, of analyzing
nature, but rather the very laws by which nature operates. That nature is governed by mathematical laws—an idea lost from the Pythagoreans--was Newton's indelible contribution. As the successes of Newtonian physics multiplied, not only in England but across the Western world, this belief intensified. The notion of a rule of natural laws governing not only the physical world but also the affairs of men became a growing thought. John Locke in philosophy, Adam Smith in economics, later Sigmund Freud in psychology and Karl Marx in politics endeavored to forge theories of human affairs in which the laws of nature were pivotal. By the early twentieth century the social "sciences" arose, attempting to follow in the footsteps of the "hard" sciences that sought fundamental physical and biological laws that govern the universe.
Why is physics, in particular the physics of Newton, so successful in predicting the behavior of the
physical world? To a great extent that success results from the self-correcting methods used by physicists in seeking truths about the universe. In scientific research there is an openness to new ideas combined with an exacting, skeptical scrutiny of all ideas. Scientific findings ultimately stem from experiments and they, along with theories describing the effects, are continually subjected to a gauntlet of criticism ranging from peer reviews of papers to be published, debates at scientific meetings, discussions at colloquia, to confrontations by colleagues. Questions are settled by refined experimentation or further calculations. Every theory is subject to repeated experimental verification. As Aldous Huxley put it, "Many a beautiful theory is spoiled by an ugly fact." The self-corrective
character of physics and the basis in experiments keep good theories beautiful. Nonetheless, physics itself, soon after the time of Newton, succumbed to the idea that the past and present could be predicted with certainty, in other word, determinism. At the end of the eighteenth century, the
French mathematician/physicist Simon Laplace advocated the idea that the universe was nothing other than a huge clockwork mechanism. In his Celeste Mechanique (Celestial Mechanics), he wrote
If an intelligence, for one given instant, recognizes all the force which animate Nature, and the
respective positions of the things which compose it, and if that intelligence is also sufficiently
vast to subject these data to analysis, it will comprehend in one formula the movements of the
largest bodies of the universe as well as those of the minutest atom; nothing will be uncertain to
it, and the future as well as the past will be present to its vision. the human mind offers in the
perfection which it has been able to give to astronomy, a modest example of such an
intelligence.
Napoleon, after having read Laplace's work commented to him that he seemed not to need God in his
description of the universe. Laplace dryly replied, "Sire, I had no need for that hypothesis."
The new science of chaos has humbled mankind once again. Rather than believing that all the
applications of mechanics were complete, chaos reveals that we have yet to understand nature in some very simple applications and that our predictive power is limited in scope.