The term enlightenment is generally used to designate a period in European history stretching from the 1680s to the close of the eighteenth century, but this usage is not without ambiguities and controversy. During the eighteenth century the word enlightenment referred not to a period but to a process, a set of activities in which individuals engaged. These activities were viewed as involving the application of what was then termed philosophy to a range of concerns in what would subsequently be classified as the natural sciences, the humanities, and the social sciences. It was not until the nineteenth century that the Enlightenment came into general usage as a designation for the historical period defined by these various projects. Attempts to specify the character of the period have tended to spur reflection on the nature and scope of those projects and activities that are claimed to characterize the age...