A historical review of the background of the theories and observations of Marshall McLuhan demonstrates that these ideas arose from or were first articulated by several antecedent social scientists. Some of McLuhan's ideas arise directly from the linguistic observations of Benjamin Lee Whorf. Other ideas show signs of having been influenced by Buckminster Fuller and Walter Ong in the area of the extension of human sensory systems through the use of machines and electronic media. Most especially, however, McLuhan's postulations are rooted in other social scientists such as Cooley, Mead, and Simmel. Along with McLuhan, these scholars have regarded communication as the integral aspect in man's adaptation to social change. This theoretical communicational base, along with his variations and refinements of earlier work, are what make McLuhan's work so important to those who seek to understand social, symbol-making man. (CH)