This book is an attempt to re-evaluate some basic assumptions about language, communication, and cognition in the light of the new epistemology of autopoiesis as the theory of the living. Starting with a critique of common myths about language and communication, the author goes on to argue for a new understanding of language and cognition as functional adaptive activities in a consensual domain of interactions. He shows that such understanding is, in fact, what marks a variety of theoretical and empirical frameworks in contemporary non-Cartesian cognitive science; thus, cognitive science is in the process of working out new epistemological foundations for the study of language and cognition. In Part Two, the traditional concept of grammar is reassessed from the vantage point of autopoietic epistemology, and an analysis of specific grammatical phenomena in English and Russian is undertaken, revealing common cognitive mechanisms at work in linguistic categories.