The Swiss philosophe Jean-Jacques Rousseau, for example, wrote a political tract, a treatise on education, constitutions for Poland and Corsica, an analysis of the effects of the theater on public morals, a best-selling novel, an opera, and a highly influential autobiography.
The philosophes wrote for a broadly educated public of readers who snatched up every Enlightenment book they could find at their local booksellers, even when rulers or churches tried to forbid such works.
Between 1740 and 1789, the Enlightenment acquired its name and, despite heated conflicts between the philosophes and state and religious authorities, gained support in the highest reaches of government.
In 1784, the German philosopher Immanuel Kant summed up the program of the Enlightenment in two Latin words: sapere aude, "dare to know", meaning, have the courage to think for yourself.
The philosophes used reason to attack superstition, bigotry, and religious fanaticism, which they considered the chief obstacles to free thought and social reform.
They believed that a society based around reason instead of religious fanaticism would improve the way people think and culminate in a more critical, scientific outlook on social issues and problems.