In structuralism-influenced studies of mythology, a mytheme is the essential kernel of a myth— it represents an irreducible, unchanging element, a minimal unit that is always found shared with other, related mythemes and reassembled in various ways ("bundled" was Claude Lévi-Strauss's image) or linked in more complicated relationships. For example, the myths of Adonis and Osiris share several elements, leading some scholars to conclude that they share a source, i.e. images passed down in cultures or from one to another, being ascribed new interpretations of the action depicted as well as new names in various readings of icons. Claude Lévi-Strauss (1908-2009), who gave the term wide circulation, wrote, "If one wants to establish a parallel between structural linguistics and the structural analysis of myths, the correspondence is established, not between mytheme and word but between mytheme and phoneme."
The structuralist analyzer of folk tales, Vladimir Propp, treated the individual tale as the unit of analysis. The unitary mytheme, by contrast, is the equivalent in myth of the phonemes, morphemes, and sememes into which structural linguistics divides language, the smallest possible units of sound, structure, and meaning (respectively) within a language system.
In the 1950s Claude Lévi-Strauss first adapted this technique of language analysis to analytic myth criticism. In his work on the myth systems of primitive tribes, working from the analogy of language structure, he adopted the French term mythème, with the assertion that the system of meaning within mythic utterances parallels closely that of a language system. Roman Jakobson varies this idea, treating mythemes as concepts or phonemes which have no significance in themselves but whose significance might be shown by sociological analysis.