French architect Pierre-François-Henri Labrouste was one of the most important architects of the Bibliothèque Nationale. The building has a hybrid aesthetic, containing elements of both classical and modern architecture. The classical elements present in Labrouste’s Bibliothèque Nationale include the ribbed vaulting, arcuated windows, domes, Greek ionic capitals that symbolize wisdom, and oculi. Some of the modern elements seen in this building include the cast-iron columns and arches, the use of reinforced plaster with iron mesh. The exposed metal frameworks and detailed masonry are characteristic of modern architecture as well.