Traces the development of the logical categories of language to the more primitive sign levels of natural events and signals. This work includes chapters that discuss the features introduced by spoken natural languages and the written specialized languages used within social institutions.

This bold venture into synthetic philosophy provides: a methodology for comparing language to primitive sign levels that avoids reductionism; comparisons and contrasts between sign levels that enable distinctions between necessary and contingent features of language; an integrative framework for relating isolated results in linguistic philosophy, experimental psychology, and ethology; and a means of resolving some of the principal metaphysical disputes derived from linguistic investigations.