The Collaborative International Dictionary of English v.0.48:

Aufklaumrung \Auf"kl[aum]*rung\, n. [G., enlightenment.]
   A philosophic movement of the 18th century characterized by a
   lively questioning of authority, keen interest in matters of
   politics and general culture, and an emphasis on empirical
   method in science. It received its impetus from the
   unsystematic but vigorous skepticism of Pierre Bayle, the
   physical doctrines of Newton, and the epistemological
   theories of Locke, in the preceding century. Its chief center
   was in France, where it gave rise to the skepticism of
   Voltaire, the naturalism of Rousseau, the sensationalism of
   Condillac, and the publication of the "Encyclopedia" by
   D'Alembert and Diderot. In Germany, Lessing, Mendelssohn, and
   Herder were representative thinkers, while the political
   doctrines of the leaders of the American Revolution and the
   speculations of Benjamin Franklin and Thomas Paine
   represented the movement in America.
   [Webster 1913 Suppl.]