Social Contract Theory: A political theory developed during the Enlightenment by philosophers like John Locke and Jean-Jacques Rousseau. It suggests that governments should be based on an agreement between citizens and their rulers.
Separation of Powers: An idea popularized by philosopher Montesquieu that proposes dividing government power among different branches (executive, legislative, judicial) to prevent tyranny.
Natural Rights: The concept that individuals have certain inherent rights such as life, liberty, property which cannot be taken away by the government. This idea was central to Enlightenment thinkers like John Locke.