This chapter contextualizes the notion of endangered languages in a model of language and society. For sociolinguists, language loss, except as a result of extinction of speakers by natural disaster or mass murder, is an extreme case of a normal ongoing phenomenon, language shift. The fact or belief that the language is appropriately used at a higher level may encourage the belief that it should be used at a lower level. Religion has a major influence on language shift and maintenance both because of the values it assigns to a variety and also as a result of the active management involved in the establishment of an educational system. Education, particularly under the control of national states, has become one of the main forces for language shift and one of the main causes of endangerment of minority-language varieties.