Intended for teachers of grades 7-16, this book discusses "heuristic" writing--writing that produces new, irreversible knowledge for the writer leading to a fuller understanding of the self and of the act of writing--as well as principles and practices having direct implications for a wide range of students. Chapter 1 examines the origins and potential of content area writing, particularly the role of everyday language in learning, contexts for learning, students' intentions for learning, how learners see themselves, encounters with models, a writer's sense of audience, conditions for good transactional writing, assessment and criticism, and becoming our own experts. Chapter 2 discusses language and thinking, specifically the origins of language and thinking, kinds of language and thought, intersection of thought and language, outcome of egocentric speech, social behavior of intellectual development, advantages of verbal thought, interaction of language and thinking, development of analytic competence, construction of imaginary worlds, evolutionary instrumentalism, and classroom implications of this perspective. Chapter 3 explores writing and the construction of knowledge, and gives examples of writing and learning. Chapter 4 discusses using writing in five courses--entomology, clinical nursing, psychology of human relations, psychology of women, and mathematics. The last chapter presents an alternative view of writing, teaching, and learning. (SRT)