This thesis will conduct an examination of the epistemologies of Etienne Bonnot de Condillac and Jean Jacques Rousseau, and compare them in conjunction with the criticism of their works in Johann Gottfried Herder's Abhandlung über den Ursprung der Sprache. I will propose that Herder's work in many places addresses the same problems in the French philosophers as Jacques Derrida and Paul de Man do in their critical theory on the subject. Most specifically, I will be examining the aspects of these works that discuss the development of human language.