The two parts thus formed are complements. In logic, the partitions are opposites if there exists a proposition such that it holds over one and not the other.

In the community of philosophers and scholars, many believe that "unless a distinction can be made rigorous and precise it isn't really a distinction."

The term comes from the Greek dichotomia (divided): dich- (form of dícha, in two, asunder); tomia- a combining form meaning cutting, incision, excision of an object.