So wrote Hilaire Belloc in a volume entitled Survivals and New Arrivals published in 1929. On this account, the period of "postmodernism" — assuming that to be an historical term — began well before the Second World War. Matters are not so simple, however, for in Belloc's "technical sense", "modernism" had a limited and unambiguous connotation and an equally determinate reference. It indicated a body of ideas developed within Roman Catholic thought by writers such as Baron von Hügel; ideas which came under ecclesiastical condemnation in the Papal Decree Lamentabili, and against which the so-titled "anti-Modernist Oath" was directed. Once one departs from Belloc's use of the term, however, it is unclear that "modernism" has any single determinate sense, and it is absolutely certain that the term "postmodernism" does not.