<P> There is little consensus on the precise beginning of the Age of Enlightenment, though the beginning of the 18th century (1701) or the middle of the 17th century (1650) are often used as epochs . French historians usually place the period, called the Siècle des Lumières ("Century of Enlightenments"), between 1715 and 1789, from the beginning of the reign of Louis XV until the French Revolution . If taken back to the mid-17th century, the Enlightenment would trace its origins to Descartes' Discourse on the Method, published in 1637 . In France, many cited the publication of Isaac Newton's Principia Mathematica in 1687 . It is argued by several historians and philosophers that the beginning of the Enlightenment is when Descartes shifted the epistemological basis from external authority to internal certainty by his cogito ergo sum published in 1637 . As to its end, most scholars use the last years of the century, often choosing the French Revolution of 1789 or the beginning of the Napoleonic Wars (1804--1815) as a convenient point in time with which to date the end of the Enlightenment . </P> <P> In the 1944 book Dialectic of Enlightenment, Frankfurt School philosophers Max Horkheimer and Theodor W. Adorno argued: </P> <P> Enlightenment, understood in the widest sense as the advance of thought, has always aimed at liberating human beings from fear and installing them as masters . Yet the wholly enlightened earth radiates under the sign of disaster triumphant . </P> <P> In the 1970s, study of the Enlightenment expanded to include the ways Enlightenment ideas spread to European colonies and how they interacted with indigenous cultures and how the Enlightenment took place in formerly unstudied areas such as Italy, Greece, the Balkans, Poland, Hungary and Russia . </P>

The age of enlightenment in england and europe