John Locke
1690 -- John Locke believed that all people were allowed life, liberty, and property by nature. He felt that the government should protect these rights. Also, he believed that the government came from the people, not God.
Montesquieu
1748 -- Claimed that any group in power will crave more power. Believed solution was to divide the government into three branches.
Rousseau
1762 -- Was an advocate for democracy. He wrote a book called the "Social Contract". This was an agreement among free individuals to create a government that would respond to the will of the people.
Adam Smith
-- He believed that there should be limited governmental interference with economy, and that the value of products and labor should be determined by the market.
ALL OF THIS INFORMATION CAME DIRECTLY FROM MY NOTES ON THE ENLIGHTENMENT.