Within the discipline of social theory, Boorstin’s 1961 book The Image: A Guide to Pseudo-events in America is notable as an early, landmark attempt to describe aspects of American life that were later termed hyperreality and postmodernity. In The Image, Boorstin describes shifts in American culture - mainly due to advertising - where the reproduction or simulation of an event becomes more important or 'real' than the event itself. He goes on to coin the term pseudo-event which describes events or activities that serve little to no purpose other than to be reproduced through advertisements or other forms of publicity. The idea of pseudo-events closely mirrors work later done by Jean Baudrillard and Guy Debord. The work is still often used as a text in American sociology courses.