The Director of the Center for the Study of the Extensions of Man at the University of Toronto, Marshall MoLuhan here investigates the psychic and social consequences of technological media on man and his societies. The medium itself, rather than the content, is the message, he asserts, and turns to inspect the manner in which it affects us. He extends his inquiry beyond the expected media of print, radio, television, telephone to include "the mechanical bride" — the automobile, clothing — "our extended skin," money, clocks, housing. He differentiates between the cool and hot media, the former leaving more for the participant or user to do, the latter more comprehensive in its content — and indicates how these affect diversely the tribal or the individualistic culture. His insights into the nature of our society, the role the media play in it, the meaning of media, the actualities of the cold war (again that temperature reading is important) are provocative and brilliant. The printed word, however, is a cold medium, and this book requires concentrated reader application for reward.