A dichotomy is a division into two non-overlapping or mutually exclusive and jointly exhaustive parts. They are often contrasting and spoken of as "opposites". The term comes from dichotomos (divided): dich- ([in] two) temnein (to cut).
A false dichotomy is not jointly exhaustive or not mutually exclusive.
Dichotomies are common in Western thought. C.P. Snow believes that Western society has become an argument culture. In The Argument Culture (1998), Deborah Tannen suggests that the dialogue of Western culture is characterized by a warlike atmosphere in which the winning side has truth (like a trophy). In such a dialogue, the middle alternatives are virtually ignored.
In biology, a dichotomy is a distribution of genera into two species. Such dichotomies are used as part of the process of classifying species, to build a taxonomic key. When classifying, a series of questions is asked which narrows down what is being examined, to indicate where it belongs in the hierarchy.
A well known dichotomy is the question "does it have a backbone?", used to divide species into vertebrates and invertebrates.
In computer science, more specifically programming language engineering, the term dichotomy is used to denote fundamental dualities in a language's design. For instance, C++ has a dichotomy in its memory model (heap versus stack), whereas Java has a dichotomy in its type system (classes versus primitive data types).
External link