In reviewing the attempts to conduct Federal antipoverty programs with "maximum feasible participation" by residents of the communities involved, Daniel Moynihan describes the origin of this provision in sociological theory, then discusses the nature and the internal contradictions of the great national effort at social change conceived under the Kennedy administration and brought to fruition under the Johnson administration. An account is given of the intellectuals' quest for community during the 1950's; the professionalization of reform; the planning and establishment of the Mobilization for Youth (MFY) on Manhattan's Lower East Side; the President's Committee on Juvenile Delinquency (1961-63) and the resulting plan for community action; the rise of HARYOU-ACT and similar organizations and the decline of MFY; and eventual conflict and disorganization within the community action movement. The author concludes that, to avoid pitfalls similar to those he describes, social scientists must have more reliable data before advocating and insisting on the adaptation of theoretical solutions for social and economic ills. An index and chapter notes are included. (ly)