Aristotle's view of nature is teleological. That is, he believed nature is explained in terms of biological and nonbiological objects seeking their end, that purpose for which a thing exists. This view answers questions such as why things move. A stone moves to the ground because the ground is its natural location. It would be unnatural, for example, to see a stone floating on water. Biological organisms also have purposes. A dog, for example, achieves its telos, or end, partly by realizing its form. A dog does not become a chicken. A man's purpose, Aristotle believed, is to be happy—that is, to flourish, or achieve well-being by actualizing the virtues.
Only 27 recorded astronomical observations made by Copernicus survive. One of them, a moon eclipse, was discussed in his book, De Revolutionibus. This became the basis for Copernicus's claim the earth revolves around the sun rather than the other way around. At the time Copernicus lived and worked, astronomy and astrology shared equal intellectual footing in what was known as the "science of the stars." Mathematical techniques were used in both fields, but there were various disagreements over the organization and order of the planets, namely the locations of Venus and Mercury. A further source of theoretical problems was Aristotle's teleological theory of the heavens. Copernicus had inherited not only these intellectual difficulties, but also the religious context that militated against his findings.
Descartes is often considered the father of modern philosophy. He believed a reliance on one's own reason, rather than the dogmatic authority of the Church, was essential to the burgeoning scientific enterprise. Descartes, himself a mathematician interested in optics, was excited by findings of thinkers such as Galileo. He also doubted Aristotle's teleological philosophy provided the correct framework within which science should be done. But at the same time, he saw some troubling implications of the new mechanistic view of the universe. One of those implications was the demise of human freedom, and so also moral responsibility. After all, if the universe is governed by mechanical laws, and human beings are elements in the universe, it follows human beings also follow mechanical laws. Therefore, human beings are not free. Descartes's response was, in part, an attempt to reconcile a mechanistic universe with a God that preserves freedom.
In 1905 Einstein published four papers that dramatically altered the course of physics. In proposing a new paradigm, Einstein threaded together elements advanced by other thinkers. In other words these thinkers had a partial view of the whole, both incomplete and inaccurate. Poincaré, for example, did not recognize a significant feature of motion. Newton's laws of motion and Maxwell's theory of light were contradictory, and it was Einstein's realization—and the implication one must be incorrect—that led to the special theory of relativity. Although his papers were originally ignored by fellow physicists, history shows Einstein's theory revolutionized the way physicists think about light and motion.
When Galileo learned of the invention of a new instrument in the Netherlands called the telescope, he lost little time in developing his own. This instrument allowed him to see great distances into space. Galileo also used the telescope to confirm Copernicus's findings and undermine Aristotle's cosmology.
The scientific revolution arguably culminates with physicist and mathematician, Isaac Newton. His work on light, motion, and calculus provided paradigms for scientists in physics for generations. The world he inherited was, in a sense, in flux. Copernicus's heliocentric paradigm in astronomy, and Galileo's mechanistic paradigm in physics—endorsed by the likes of Descartes—battled with religiously motivated holdovers from the Aristotelian geocentric worldview. The time was ripe for Newton to introduce his theories. These theories would establish the paradigm for physics until Einstein's work in the 20th century.