One might think that archaeology would have to disregard the information contained within religions and many philosophical systems. However, apart from the great deal of factual material that such systems generate (such as places of worship, holy objects and other scientifically observable things), there are other aspects that are equally important for scientific archaeological investigation such as religious texts, rites, customs and traditions. Archaeologists and historians commonly use myths as clues to events or places that have become hidden in the background, a process that Rudolf Bultmann calls "demythification" – the most notable example being Homer’s poems and the myth-infused city of Troy.