In our description of cultural change in western society we have encountered a number of dramatic events. Though varying in methods and scope, these have all been descriptions of internal change brought about be external stress. But the changes that occurred during the middle ages were entirely internal. From the disintegration of the Roman Empire to its reconstruction under Charlemagne it was largely a matter of developing stable institutions which would provide continuity to a largely rural Europe. However true, this statement is misleading because it suggests the existence of some structural mechanism which would choose which of the possible cultural institutions should be selected, as though some higher power chose feudalism after considering all other possibilities. Most discussions of the period describe the currents of change occurring in western society as though they had a dynamic existence of their own. There is no higher cultural structure, and social and cultural systems do not live breath and walk on their own. Feudalism emerged out of the anarchic interactions of men who considered themselves free. The stability it provided was insured only by its own success. But, from the Carolingian period to the thirteenth century another counter culture slowly emerged, that of the cities, of commerce and industry. At the time of Charlemagne the church owned most of the land in Europe. The realities of feudalism provided the church with a solid economic base and made it one of the stabilizing structures in the new developing world. But by the thirteenth century land was no longer the primary source of wealth in western society and by the sixteenth century the church leaders found themselves deriving their financial support directly from the people. The role of the church as a stabilizing element had been essentially destroyed and nothing had emerged to take its place.

The validity of truth through revelation had been insured by the power of the church. With the advent of the reformation revealed truth was often applied in contradictory terms by conflicts in biblical interpretation, some theologians of the sixteenth and seventeenth centuries called on people to turn away from the teachings evolved from church structure and turn instead directly to the bible. For example, in "The Handbook of the Militant Christian," the catholic theologian. Erasmus mentioned two important weapons to be used in combating vice, prayer and knowledge. This knowledge was to be developed through reading the bible and through a study of Pagans such as Virgil and Plato. Erasmus was calling on Christians to find their own truth while remaining faithful to the Catholic church.

. Martin Luther found his answer to the problem of truth in a severe Augustinian reading Paul's Epistle to the Romans.

There I began to understand that the righteousness of God is that by which the righteous lives by a gift of God, namely of faith. And this is the meaning; the righteousness of God is revealed by the gospel, namely the passive righteousness with which merciful God justifies us by faith.

In this passage he recognized what he found to be the total meaning behind Augustine's theory of Grace. he said, . "Man being a bad tree, can only will to do evil." Only through faith does man know good from evil, "Every deed of the law without the grace of God appears good outwardly but inwardly it is sin." And finally, "We do not become righteous by doing righteous deeds but, having been made righteous we do righteous deeds." But this knowledge is only of God and man's relationship directly to him. Philosophical knowledge is something entirely different. He said that Philosophical truth is to theological truth as law is to gospel, or as human righteousness is to divine righteousness. "Indeed," he said,. "no one can become a theologian unless he becomes one without Aristotle." Thus knowledge can only come from God as a gift of grace to man.

The theological rejection of reason, although important, had a less dramatic effect on the culture of the period than the discovery of physical laws. The world according to Aristotle operated for a reason. Of his four causes for any event the most important was the final cause, or the purpose for which the event occurred. Given these assumptions, in spite of the mathematical problems involved in an earth centered universe, nothing else made any sense. Why should an absolute intellect build a universe in which the abode of the only rational animal, mankind, was an insignificant planet in a minor star system on the edge of an outlying spiral Galaxy? The movements of the stars, planets, sun, and moon had always been considered divine, eternal. As such, applying pure reason leads to the conclusion that us they can only be circular. Any other description would require a catastrophic change in the medieval conception of reality. And in the seventeenth century just such a change occurred. Copernicus had found that when he substituted the sun for the earth as the center of the universe it simplified his mathematics. This was not really a problem until Galileo looked in his telescope and when he discovered physical laws.

Instead of reasoning about what happens when a ball drops freely from a height or rolls down an inclined plane, Galileo made experimental observations and then reasoned from the outcome of these observations. What he found was that objects in nature follow inviolable laws of nature which are irrelevant to the reasons for the events. He had heard about the invention of the telescope but he was not able to obtain one so he built his own, an improvement on those that had been built before. When he pointed it at the stars he discovered two things that were not consistent with the Aristotelian paradigm. First, the number of stars was considerably greater than expected. Second, he found when he looked at the planet Jupiter that it had satellites revolving around it much like the earth's moon. Following that, an event occurred which clearly violated the Aristotelian paradigm. A comet made its appearance passing through what was believed to be the crystal spheres upon which the sun, moon, and planets were carried around the world. When he called the world's attention to, his condemnation has always been held up as a prime example of a conflict between the Church and science. But from this description you can see that such a description is much too simplistic. The discoveries of Galileo threatened not only the Church, it threatened the entire edifice of the western cultural concept of reality. During the century more scientific advancements culminating in Newton's complete elucidation of physical laws resulted in the emergence of an entirely new and unique western concept of reality. Rationalism, or an attempt to develop a view of the universe entirely through reason was essentially a philosophical reaction to these intellectual changes. Aristotle's description of the universe was rational as well, but it began with the assumption that the most important cause for anything was the final cause, or the reason for its coming to be. This new rationalism began with a different kind of assumption. The seventeenth century assumptions that the most important cause was the efficient cause, and that all causes of change are rooted in natural law. As such it played a large part in this transformation. The philosophers we are about to discuss lived through and reacted to these turbulent years. The first, Descartes, was a contemporary of Galileo and the last, Leibniz, of Newton.