The most influential french philosopher for the french REVOLUTION is absolutely Rousseau. Rousseau’s writing was terse, concise, and PROFOUND. His notion of the General Will, for example, was the backbone of the MOVEMENT led by Robespierre, whereby defectors or dissenters were ‘forced to be free’ (off with their head!) for non-compliance with the General Will. His IDEAS about the Sovereign and legitimate government also were impactful. For example, the way in which a magistrate assumes the General Will as his/her particular will was novel and essential to what he called an ‘energetic’ government.

I would go as far to say that the French Revolution, and especially the reign of terror, wouldn’t have taken place had ROSSEAU not published not only the Social Contract but also a series of influential works, i.e. the discourses, the emil, etc. His ideas collected and empowered the French people around one idea, viz. the supreme direction of the General Will.

For this reason, some refer to Rosseau as the father of modern totalitarianism, but I believe that interpretation is a gross misread of his works.