Abstract

The book offers a new treatment of the capacity to perceive, act on, and know about the world together with others. I argue that creatures capable of joint attention stand in a unique perceptual and epistemic relation to their surroundings: they operate in an environment that they, through their communication with their fellow perceivers, help constitute. I show that this relation can be marshaled to address a range of questions about the social aspect of the mind and its perceptual and cognitive capacities. I begin with a conceptual question about a complex kind of sociocognitive phenomenon—perceptual common knowledge—and develop an empirically informed account of the spatial structure of the environment in and about which such knowledge is possible. In the course of his argument, I address such topics as demonstrative reference in communication, common knowledge about jointly perceived objects, and spatial awareness in joint perception and action.