The term taboo derives from various Polynesian languages where it has the sense of 'forbidden'. More specifically, what is forbidden and dangerous is unregulated contact between the everyday world and the sacred, which includes both the holy and the unclean. Taboos have the function of keeping separate what must not be joined - of policing the boundaries between sacred and profane, and between 'good' and 'bad' sacred - while rites in general re-create the solidarity of the group. Pollution behaviour and taboo focus on that which is ambiguous in terms of cherished categories. There is even a sense in which taboos entrench the categories by highlighting and defining the boundaries between them. Creatures like the pig, or the camel, hare and hyrax are abominated and tabooed. The anthropological notion of totemism was invented by J. F. McLennan and condemned to oblivion by C. Levi-Strauss. Following McLennan, W. H. R. Rivers formulated a definition widely accepted by the anthropological community.