Abstract
Besides the positions that historical statements have psychologistic implications (Berlin) or are scientific only if explanatory procedure involving general statements is employed, another possibility exists. Written descriptive history can be rendered in truth-functional sentences. A system of language signs-predicate letters, constants, superscripts, subscripts, and two logical signs-is constructed for these sentences. This enables lexicographical ordering and hence machine-programming. Among the requirements of a descriptive history constituted of such sentences are that there be "quickly-decidable" sentences about individuals only and that statements involving belief, probability, or other modality be excluded. Examples of proper formulation are given, and the value of the rules and techniques of this extensional treatment of history-writing to actual history-writing is asserted.