Abstract
The concept of "non-antagonistic contradiction" (NAC) was developed in the early 1930s in the Soviet Union to describe the social contradictions of Soviet society. This concept was employed to claim that Soviet social contradictions could be resolved without becoming intense or leading to social upheavals. The numerous attempts by Soviet philosophers to explain the NAC concept resulted in theories that are subject to decisive objections. In particular, the contradictions among the working class, the peasantry, and the intelligentsia of the USSR did not prove to be non-antagonistic according to any of the theories designed to support that characterization. The reasons for the failure of the NAC concept are not confined to the Soviet context, and suggest that the NAC concept represents an important error in dialectical theory