Structural anthropology is a school of sociocultural anthropology based on Claude Lévi-Strauss' 1949 idea that immutable deep structures exist in all cultures, and consequently, that all cultural practices have homologous counterparts in other cultures, essentially that all cultures are equitable. Lévi-Strauss' approach arose in large part from dialectics expounded on by Marx and Hegel, though dialectics (as a concept) dates back to Ancient Greek philosophy. Hegel explains that every situation presents two opposing things and their resolution; Fichte had termed these "thesis, antithesis, and synthesis." Lévi-Strauss argued that cultures also have this structure. He showed, for example, how opposing ideas would fight and were resolved to establish the rules of marriage, mythology and ritual. This approach, he felt, made for fresh new ideas. He stated: In South America he showed that there are "dual organizations" throughout Amazon rainforest cultures, and that these "dual organizations" represent opposites and their synthesis. As an illustration, Gê tribes of the Amazon were found to divide their villages into two rival halves; however, members from each half married each other, resolving the opposition. Culture, he claimed, has to take into account both life and death and needs to have a way of mediating between the two. Mythology (see his several-volume Mythologies) unites opposites in diverse ways. Three of the most prominent structural anthropologists are Lévi-Strauss himself and the British neo-structuralists Rodney Needham and Edmund Leach. The latter was the author of such essays as "Time and False Noses" (in Rethinking Anthropology). Influences Lévi-Strauss took many ideas from structural linguistics, including those of Ferdinand de Saussure, Roman Jakobson, Émile Durkheim and Marcel Mauss. Saussure argued that linguists needed to move beyond the recording of parole (individual speech acts) and come to an understanding of langue, the grammar of each language. Lévi-Strauss applied this distinction in his search for mental structures that underlie all acts of human behavior: Just as speakers can talk without awareness of grammar, he argued, humans are unaware of the workings of social structures in daily life. The structures that form the "deep grammar" of society originate in the mind and operate unconsciously (albeit not in a Freudian sense). Another concept was borrowed from the Prague school of linguistics, which employed so-called binary oppositions in their research. Roman Jakobson and others analysed sounds based on the presence or absence of certain features, such as "voiceless" vs. "voiced". Lévi-Strauss included this in his conceptualization