William E. McMahon: Did Montague Invent «Montague Grammar»? Is Montague Grammar a variant of categorial grammar? After a careful examination of Ajdukiewicz's, Bar Hillel's and Bochenski's categorial theories, the author says in conclusion that Montague Grammar is not reducible to Ajdukiewicz categorial grammar and that it is not simply a categoriaI grammar. There is in Montague Grammar a synthesis of recent developments in logical theory which transcends categorial theory. But we have to make a distinction between assessing its originality and accepting its empirical relevance.