The movement that directly inspired the Third Estate during the French Revolution was the Enlightenment Reformation.
The Enlightenment was a movement of ideas and philosophies that had reason as the center of its system of concepts. In political theory, one of the main propositions of this movement was the idea of a social contract as the source of the government's legitimacy (relevant authors which adopted this position were John Locke and Jean-Jacques Rousseau). This political approach undermined the absolutist monarchy government of France and was one of the main reasons of the French Revolution.
