The military rebellion of July 18, 1936, which began the Spanish Civil War also triggered a social revolution that the leaders of the working class neither expected nor directed. This revolution immediately posed a crucial question for those in the Republican camp: What was the nature of the Republic to be? Should the revolution continue, or should the Republic be preserved as a liberal-democratic and essentially capitalist regime? This was the central issue of a struggle that pitted the anarcho-syndicalists of the CNT-FAI,1 dissident communists of the POUM, and left Socialists against Republicans, right So cialists, and the official Communists in the PCE and PSUC. The second posi tion won out, and the revolution was contained and reversed in a surprisingly short time. The Spanish conflict of 1936-39 was at once civil war and social revolu tion with a struggle for dominance within each camp. The existence of these multiple conflicts and the nature of their resolution, especially in the Republi can zone, have made the Spanish Civil War the subject of controversies which today, nearly 50 years later, show little sign of abating.2 The two books under review address themselves to one of the most debated and least understood aspects of the Spanish civil war: the collectivizations that took place in the rev olutionary summer and fall of 1936. The central concern of W. L. Bernecker's book is to explain the ease with which the social revolution of the summer of 1936 was neutralized by the more conservative elements in the Republican zone. The study of the anarcho syndicalist collectives, which both the book's title and the author's stated ob jectives (17) lead us to expect, is actually a subordinate element in the book. Bernecker's explanation focuses on the CNT-FAI, emphasizing the inability of its leadership to make better use of the spontaneous revolutionary enthusiasm