Background
The Enlightenment developed as an extension of the Scientific Revolution.  During the  Scientific Revolution, Europeans discarded traditional beliefs and began using reason to explain the world around them.  While the Scientific Revolution focused on the physical world, the Enlightenment attempted to explain the purpose of government, and describe the best form of it.  The most influential Enlightenment thinkers were Thomas Hobbes, John Locke, Voltaire, Baron de Montesquieu, and Jean Jacques Rousseau.

Later Developments
During the Enlightenment, political philosophers, especially in France and England, proposed alternatives to monarchy as a form of government.  The French philosophes, as they were known, suggested mankind needed government, but not an absolute monarchy like that of Louis XIV under which they lived.

Where the political philosophers disagreed, was on what kind of government was the best.  Some said monarchy was best, while others claimed it was democracy.  A few claimed that a monarchy with democratic elements would work best.  Still others, believed that economics played a major role in what kind of government people chose.

In the end, the philosophes could not agree upon the merits of any single form of government.  It was from those discussions that the American Founding Fathers derived many of their ideas about equality, freedom and the sanctity of life.

Impact
Enlightenment ideas helped to stimulate people's sense of individualism, and the basic belief in equal rights.  This in turn led to the Glorious Revolution is Britain, the American Revolution, the French Revolution, and the Latin American Revolutions. Some of these revolutions resulted in government based upon the ideas of the Enlightenment.  On the other hand, several failed revolutions resulted in even stricter government control of everyday life.

Elsewhere, a few monarchs retained absolute control of their countries while also enacting reform based on Enlightenment ideas.  These monarchs are called Enlightened Despots.  In Austria, Maria Teresa and her son Joseph II both introduced reforms based on Enlightenment ideas.  They reduced the tax load on the peasants, provided free education, and ended censorship in their empire.  In Russia, Catherine the Great introduced similar reforms.  She enacted laws for religious toleration and free education, and also sought the advice of nobles and peasants in the running of government. However, these reforms seldom outlived the monarchs who had enacted them.