engaged in divers activities. Radio, once a form of group 
listening that emptied churches, has reverted to private and 
individual uses since TV. The teenager withdraws from the TV 
group to his private radio.

     This natural bias of radio to a close tie-in with diversified 
community groups is best manifested in the disk-jockey cults, 
and in radio’s use of the telephone in a glorified form of the old 
trunkline wire-tapping. Plato, who had old-fashioned tribal ideas 
of political structure, said that the proper size of a city was 
indicated by the number of people who could hear the voice of 
a public speaker. Even the printed book, let alone radio, renders 
the political assumptions of Plato quite irrelevant for practical 
purposes. Yet radio, because of its ease of decentralized 
intimate relation with both private and small communities, 
could easily implement the Platonic political dream on a world