As a historical category, the term "Enlightenment" refers to a series of changes in European thought and letters. It is one of the few historical categories that was coined by the people who lived through the era (most historical categories, such as "Renaissance," "early modern," "Reformation," "Tokugawa Enlightenment," etc., are made up by historians after the fact). When the writers, philosophers and scientists of the eighteenth century referred to their activities as the "Enlightenment," they meant that they were breaking from the past and replacing the obscurity, darkness, and ignorance of European thought with the "light" of truth. Although the Enlightenment is one of the few self-named historical categories, determining the beginning of the Enlightenment is a difficult affair, as we noted earlier in this module. Not only can we not easily find a beginning to the Enlightenment, we can't really identify an end point either. For we still more or less live in an Enlightenment world; while philosophers and cultural historians have dubbed the late nineteenth and all of the twentieth century as "post-Enlightenment," we still walk around with a world view largely based on Enlightenment thought. So in the spirit of not dating the Enlightenment, we will simply refer to the changes in European thought in the seventeenth century as "Seventeenth Century Enlightenment Thought," with the understanding that our use of the term may invite criticism. The main components of Enlightenment thought are as follows: The universe is fundamentally rational, that is, it can be understood through the use of reason alone; Truth can be arrived at through empirical observation, the use of reason, and systematic doubt; Human experience is the foundation of human understanding of truth; authority is not to be preferred over experience; All human life, both social and individual, can be understood in the same way the natural world can be understood; once understood, human life, both social and individual, can be manipulated or engineered in the same way the natural world can be manipulated or engineered; Human history is largely a history of progress; Human beings can be improved through education and the development of their rational facilities; Religious doctrines have no place in the understanding of the physical and human worlds. http://www.wsu.edu/~dee/ENLIGHT/PREPHIL.HTM