'From this standpoint, one would expect to find that transitional beings are particularly polluting, since they are neither one thing nor another; or may be both; or neither here nor there, or may even be nowhere (in terms of any recognized cultural topography), and are at the very least "betwixt and between" all the recognized fixed points in space time of structural classification'.
Turner, V. 1986. The Forest of Symbols. Aspects of Ndumbu Ritual: Cornell University Press.
Chapter 5, Betwixt and Between: The Liminal Period in Rites de Passage - p.97