"Crystallizing Public Opinion" by Edward L. Bernays is a book published in 1923. Often considered the first work to define the field of public relations, it reveals how to shape mass opinion through strategic messaging. Bernays explains the role of the public relations counsel, who studies group psychology and creates news rather than merely reports it. Drawing on theories of herd mentality and stereotypes, he details techniques for influencing diverse audiences by appealing to their group identities, emotions, and existing beliefs. (This is an automatically generated summary.)