The central idea of the text "The Manipulation of the American Mind: Edward Bernays and the Birth of Public Relations" is to explore how Edward Bernays, the father of public relations, used his knowledge of psychology and propaganda to manipulate the American public into accepting certain ideas and behaviors. The author argues that Bernays' techniques were instrumental in creating a consumer culture and shaping public opinion on a wide range of issues, from smoking to political campaigns. The text also examines the ethical implications of Bernays' work and raises questions about the role of public relations in modern society.