The school has seven departments in its "Sciences" section: mathematics, physics, computer science, chemistry, biology, geoscience and cognitive science. It also has eight departments in its "Letters" section: philosophy, literature, history, classics, social science, economics (this section is the base of Paris School of Economics), geography, and art history and theory. In addition to these fifteen departments, a language laboratory for non-specialists offers courses in most major world languages to all the students. Additional centres of research and laboratories gravitate around the departments, which function as nodes of research.