'The English-language edition of the theoretical organ of the International Executive Committee of the Fourth International'. Published in Amsterdam (first four issues) and Rome (last two issues). Six issues of this quarterly publication. Numbers 3 to 6 (Summer and Autumn 1958; Winter and Spring 1959; Numbers 11 and 12 (Autumn 1960 and Winter 1960-61). All in pretty good condition apart from rusting to the staples. Contributors include Pierre Frank, Michel Pablo.