Binary
opposition is the principle of contrast between two mutually exclusive terms:
on/off, up/down, left/right etc; an important concept of structuralism,
which sees such distinctions as fundamental to all language and thought. The
theory of phonology developed by Roman Jakobson uses the concept of
'binary features', which are properties either present or absent in any phoneme: voicing, for example is present in /z/ but not in /s/. This concept
has been extended to anthropology by Claude Levi-Strauss (in such oppositions
as nature/ culture, raw/cooked, inedible/edible.