Dharma-sutra, any of several manuals of human conduct that form the earliest source of Hindu law. They consist chiefly of sutras (“threads” or “strings”) of terse rules containing the essentials of law concerning interpersonal relations and the relationship between people and the state. The maxims deal with the practical rules of caste and of human beings in their social, economic, and religious relations. Formulated in prose, they were intended to be committed to memory and expounded orally by teachers—thus forming, as it were, epitomes of class lectures. Eventually these rules came to be interspersed with stanzaic verses in various metres, each generally giving the substance of the rule immediately preceding it. The verses themselves became increasingly popular and ultimately led to the appearance of works entirely in verse. These metrical versions of previously existing Dharma-sutras came to be called Dharma-shastras, though in modern times that term more commonly is used to denote the whole body of customary rules and observances governing Hindu religious and social life.