A study of informal networks in Soviet science, this article documents the existence of a complex system of interlocking and overlapping channels ofprofessional communication that cut across the formal, hierarchical chains of command in the USSR Academy of Sciences. Through coauthorship data and career histories, one can identify science schools, research groups, social circles, and professional cliques in the Soviet scientific community during the Stalin, Khrushchev, and Brezhnev regimes. There was an expansion and integration of social circles over time and (...) a pluralism of interdependent, but distinct, scientific elites. This structure took on political significance through the persistence of a liberal democratic tradition among scientists in the Academy. (shrink)