It is often difficult to put a single set in stone definition on collective memory because it is a concept that is used in sociology, literary theory, history, geography, anthropology and political science, allowing each to fairly put its own particular or unique spin on the definition. This is seen in Kammen’s (1997) definition where he suggests that collective memory is "the publicly presented past: … speeches and sermons, editorials and school textbooks, museum exhibitions, historic sites, and