The concern of this book is to examine written language and its relation to what is ordinarily understood by the term oral language, the process of its acquisition, and the place of written language in the process of mental development. The eight chapters (1) examine the relation of written language to oral language and trace the phonocentric canon, (2) critically scrutinize the phonocentric canon and argue that the vast preponderance of evidence does not sustain the view of the naturalness of oral language and the unnaturalness of written language, (3) take up certain principles of functional differentiation and reexamine oral and written manifestations of language in light of the principle of functional differentiation, (4) explain some central features of a general model of psychological development, (5) discuss the written norm of language as partly constituted by particular cultural practices and institutions, (6) propose a model of monologic text based on structural-functional lines, (7) detail the parallels between text construction strategies and the logic of operational thought, and (8) tie together three themes: the distinctive nature of written language as partly constituted by cultural practice, the dual biological and cultural determinants of psychogenesis, and the mediated nature of much of ontogenesis. (HOD)