By applying Mauss's theory to data such as Mead's, Lévi-Strauss proposed what he called alliance theory. He argued that, in "primitive" societies, marriage is not fundamentally a relationship between a man and a woman, but a transaction involving a woman that forges a relationship—an alliance—between two men. His "Elementary Structures of Kinship" takes this as a starting point and uses it to analyze kinship systems of increasing complexity found in so-called primitive societies (that is, those not based on agriculture, class inequalities, and centralized government).