Pierre-Olivier Dittmar is a historian, lecturer at the Ecole des Hautes Etudes en Sciences Sociales (EHESS) where he holds the chair of history and anthropology of the living (12th-16th century). His work focuses on the interfaces with non-humans during a long Middle Ages, whether animals, invisibles, or artifacts. He notably co-wrote Image and transgression in the Middle Ages (PUF 2008) and The Romanesque World Beyond Good and Evil (2012), directed or co-directed Adam and the astragalus. Anthropology and history essays on the limits of the human (MHS 2009), an issue of Re-vues images dedicated to Become-animal (n°6 2009) and more recently Images in the Medieval West (Brepols 2015), as well as Materialize desires. Votive techniques.