Gustave Le Bon: A “Scientific Irregular” and His Media

Abstract In the second half of the 19th century, among his many other activities, French scholar Gustave Le Bon built his career by giving lectures illustrated with optical lantern slides. He pursued what could be called a “cross-media strategy” to promote his work. He combined public lectures and publications on a variety of subjects, theoretical studies as well as handbooks. He was clearly business-oriented, and marketed not only his books but also lantern slides and even apparatuses. After his first illustrated lectures in the early 1870s, Le Bon developed a photographic method for location surveys and applied chronophotography to the training of horses while continuing his lecturing activities. This article aims to reconstruct Le Bon's specific “scientific persona” in this first period of his career and analyse the fundamental role played by his engagement with optical media, in particular photography. It will argue that both his cross-media strategy in science popularisation and his engagement with the medium of photography made it possible for him to acquire a position outside academic institutions as a central figure in the French intellectual landscape of the late 19th and early 20th centuries.