Bruno Latour (born 1947) is making waves. He started as a "lover" of the sciences and technology, as a co-founder of Actor-Network Theory (ANT), and as a philosopher of a modernity that has never been modern. He is now not only one of the most popular representatives of science studies but also a "great renovator of the social sciences" and an exemplary boundary-crosser between the natural and social sciences. This introduction provides a comprehensive overview of his work for the first time, from his early anthropological studies in Abidjan (Ivory Coast) to his recent reflections on an empirical metaphysics of modes of existence. It becomes clear that Latour addresses the fundamental problem of social transmission, the tradition of experiences and knowledge.