The body is at the heart of Merleau-Ponty’s philosophy. The theme is anticipated by the study of animal and human behaviour in The Structure of Behavior (1942) and is central to Phenomenology of Perception (1945), which is our focus. Against Descartes and the usual contemporary view of the body as a biomedical object or as a vehicle of consciousness, the Phenomenology demonstrates that one is one’s body. There is no ontological separation between the experiencing “I” and the body as one lives it. Indeed, the lived body is one’s intentional opening to the world, through which alone one experiences meaningful things in the first place.