For more than two thousand years, the study of translation has been under the influence of Aristotle’s conception of categories, and translation theory continues to be structured in binary oppositions. This paper proposes that we turn to the prototype theory, developed in cognitive science since the 1970s, for the basis of a more rational account of translational activities. In the light of the core notion of “translational prototype”, the author takes a fresh look into translation’s categorical properties, and addresses various other ontological issues concerning its nature and criteria.