Much recent research on human evolution emphasizes that social behavior and cognition are at the heart of everything that is distinctively human. This body of research generally understands sociality in terms of social reasoning and the brain that supports it. Human Flesh shifts the focus. What if human sociality is not primarily or exclusively located in the brain but rather is distributed throughout the body? What if the foundation of the human way of life lies in intercorporeity: the ways in which our affective, sensorimotor social bodies-our eyes, hands, voices, ears, and desires-open our bodies and minds up to one another? Human Flesh develops a framework for exploring these questions based on Merleau-Ponty's unfinished work on human evolution, combining it with contemporary research in phenomenology, embodied cognitive science, evolutionary anthropology, and primatology. It applies that framework to explore how the different senses and sensory organs take on their distinctively human variations to facilitate the intercorporeal, social human form of life. Along the way, the book interprets familiar facts about the human body in a new light and develops novel hypotheses concerning human evolution. In contrast to the widely discussed social brain hypothesis, its guiding premise is the social body hypothesis: the proposition that the human body has evolved in response to the challenges posed by the distinctively human social form of life. Based on these concrete investigations into the human body, Human Flesh proposes a new way of thinking about familiar topics in the evolution of cognition literature, such as the emergence of higher orders of social cognition and the development of human symbolic and linguistic capacities. Ultimately, the book arrives at a new determination of human nature and the human form of life: To be human is to be Homo invisibilis, an animal obsessed with, adapted for, and dependent upon the invisible minds of other humans and the symbolic-cultural worlds opened up by their unique social bodies.