 According to Olivelle, purity-impurity is discussed in the Dharma-sastra texts, but only in the context of the individual's moral, ritual and biological pollution (eating certain kinds of food such as meat, going to bathroom).Olivelle writes in his review of post-Vedic "Sutra" and "Shastra" texts, "we see no instance when a term of pure/impure is used with reference to a group of individuals or a "varna" or caste".The only mention of impurity in the "Shastra" texts from the 1st millennium is about people who commit grievous sins and thereby fall out of their "varna".