Today the Enlightenment is often viewed as a historical anomaly, a brief moment when a number of thinkers infatuated with reason vainly supposed that the perfect society could be built on common sense and tolerance, a fantasy which collapsed amid the Terror of the French Revolution and the triumphal sweep of Romanticism. Religious thinkers repeatedly proclaim the Enlightenment dead, Marxists denounce it for promoting the ideals and power of the bourgeoisie at the expense of the working classes, postcolonial critics reject its idealization of specifically European notions as universal truths, and postructuralists reject its entire concept of rational thought.
Yet in many ways, the Enlightenment has never been more alive. The notions of human rights it developed are powerfully attractive to oppressed peoples everywhere, who appeal to the same notion of natural law that so inspired Voltaire and Jefferson. Wherever religious conflicts erupt, mutual religious tolerance is counseled as a solution. Rousseau's notions of self-rule are ideals so universal that the worst tyrant has to disguise his tyrannies by claiming to be acting on their behalf. European these ideas may be, but they have also become global. Whatever their limits, they have formed the consensus of international ideals by which modern states are judged.
If our world seems little closer to perfection than that of 18th-century France, that is partly due to our failure to appreciate gains we take for granted. But it is also the case that many of the enemies of the Enlightenment are demolishing a straw man: it was never as simple-mindedly optimistic as it has often been portrayed. Certainly Voltaire was no facile optimist. He distrusted utopianism, instead trying to cajole Europeans out of their more harmful stupidities. Whether we acknowledge his influence or not, we still think today more like him than like his enemies.
As we go through his most influential work, The Philosophical Dictionary, look for passages which helped lay the groundwork for modern patterns of thought. Look also for passages which still seem challenging, pieces of arguments that continue today.