Roland Barthes identified five codes that are included in narratives: the hermeneutic code, the proairetic code, the semantic code, the symbolic code, and the cultural code. Levi Strauss studied myths and legends and discovered that humans make sense of the world through binary opposites such as war/peace. Barthes and Strauss collaborated and concluded that words are symbols for societies, ideas, and meanings, and that binary opposites are central to narrative structure.