In the social sciences a division is often made between theories of action and theories of meaning, where the first (e.g. Barth or Marx) ask what an act or thing is in itself, while the others (e.g. Lévi-Strauss or Geertz) ask what it means for us (see culture). Messages that are communicated between people are called meaning. Meaning can be understood and analyzed from a range of different viewpoints: semiotics, structuralism, cybernetics, performance theory, etc. The theories are often complex and use a rich vocabulary of (often ambiguous) terms: symbols, signs, metaphors, metonyms, icons, identities etc. (See information, cognition, culture, discourse, ethos, legitimacy, metacommunication.)