Human social organisation intrinsically includes borders, divisions that mark inside and outside, civilised and barbaric, acceptable and unacceptable. Human groups establish physical and ideational boundaries that help order, explain, and direct their lives. Those groups and activities that blur or cross over these lines receive special attention, as their violations of or challenges to what are presented as logical, natural, and moral standards force their reconciliation with generalised norms. Such people and actions are categorised as immoral, uncouth, detrimental, seditious, or non-human. They are also often considered endowed with special powers.