Caste is a system of social stratification based on heredity and, within the caste group, members are restricted in their choice of occupation and social participation. Marriage outside of the caste is usually prohibited. In Hindu religious texts, the Manusmitri (The Law of Manu) legitimizes social exclusion and inequality as the guiding principle of social relations. Those from the lowest castes are told that their place in the caste hierarchy is due to their sins in a past life and the result has been a long history of discrimination against Dalits by the higher castes. The caste system has served the interests of the higher castes, which have resisted any reforms.