Essay, Research Paper
Before the scientific revolution, the Catholic or European worldview was essentially a mixture of the theories of Aristotle and Ptolemy. It is important for the contemporary student of the scientific revolution to keep in mind the intellectual background of the Middle Ages and not to judge the scientists of the Middle Ages as ignorant or lacking important observational skills. Aristotle set the stage for the common views on motion and its causes, and a mixture of the theories of Aristotle and Ptolemy was responsible for the Catholic’s idea of astronomy. The field of what today is known as dynamics was in the middle ages a highly erroneous theory based on the precedent that all heavy terrestrial bodies had a natural motion towards the center of the universe, the center of the earth, while motion in any other direction was violent motion and required the operation of a “mover” (Butterfield 15). According to the theory of Aristotle as soon as the mover ceased to operate the body fell straight to earth or the dropped suddenly to rest. The speed of the body was dependent upon and directly proportional to the force exerted by the mover. In other words a constant force provided uniform motion. Furthermore Aristotle stated that the speed of the object was inversely proportional to the resistance of the medium through which the body traveled, and if the resistance was reduced to zero, the speed would be infinite. Therefore, Aristotelians regarded a complete vacuum as impossible, stating that even God Himself could not create one (Butterfield 16). The theory came to a brilliant peak in the manner by which it accounted for projectile motion such as the flight of an arrow. The idea was that as the projectile traveled through the air, the air that was pushed and compressed in the front had to rush around behind the object to prevent a vacuum from forming. “The motion of the projectile, since it was caused by a disturbance in the medium itself, was a thing which it was not possible to imagine taking place in a vacuum” (Butterfield 18). It should be added that the velocity of the projectile in the vacuum while it was being “pushed” by the mover would be infinite, since resistance would be nil. Aristotle not only formed the basis for the European’s view of dynamics, but also formed the majority of astronomical thought as well. The Catholic’s view of astronomy was also highly erroneous and was a combination of the ideas of Aristotle and Ptolemy, but is found by Butterfield to be best explained by Dante, a Catholic writer. First of all, they viewed matter as being composed of one or a mixture of the four elements earth, water, air, and fire. The first two being drawn to earth and the latter having a natural to tendency to rise. They viewed the heavenly bodies, sun, moon, and stars, to be composed of a fifth, incorruptible element and was attached to spheres composed, according to Aristotle, of a very subtle ethereal substance, moving more softly than liquids and without any friction (Butterfield 32). But with the passage of time the common view came to be that the spheres were glassy or crystalline globes, solid but still transparent. According to Dante there were ten skies, the last being the Empyrean Heaven, home of God and without motion, while the first was nearest to earth and carried the moon. The next six carried the sun and the planets, while the eighth carried the stars. The ninth globe had no visible signs of existence, but they thought it must be there to turn the whole system of spheres from east to west once every twenty-four hours (Butterfield 32). Finally, according to Dante, all the various spheres are moved by Intelligences or Spirits, the lowliest of whom are the angels who move the sphere of the moon (Butterfield 34). It was the authority of Aristotle and his successors that was responsible for all these beliefs, even the ones which may seem to have been created by the church-the hierarchy of heavens, the revolving spheres, the Intelligences which moved the planets, and the view of matter being composed of four elements with the celestial bodies being composed of the incorruptible fifth essence. The beauty of this essentially Aristotelian system had been gravely compromised by the improvements in astronomical observation which took place early in the Christian era. In the age of Ptolemy, the complications had become serious, and the whole celestial machinery needed further elaboration to account for the planets which in no way followed uniform circular motion. Ptolemy developed an elaborate description of this strange motion by stating that epicycles, or smaller spheres attached to the larger ones as above mentioned, were the means by which the planets followed such strange paths in the sky. The whole system required eighty spheres however and many writers differed in their opinion on just how many spheres the sky contained and how to truly account for the strange paths of the planets.
All this set the stage for the scientific revolution. For since the heavens were composed of a complex system of spheres and celestial machinery, there was no clear, simple, or rational explanation for the movements of all the heavenly bodies. Therefore, new systems were soon to be devised and the believers in the old systems were more than ready to jump to the defensive in order to conserve their established beliefs. As in the words of Einstein, “Great ideas have always encountered violent opposition from the mediocre mind.” But nonetheless, change did come, but not without a long, hard, and sometimes violent struggle.