Intended for teachers, this monograph encourages readers to consider the notion that thinking critically is a matter of reading signs, that it is the function of signs that makes reflective thinking possible. The book contains the following chapters: (1) "Beyond a Literal Reading"; (2) "Current Thinking on Critical Thinking"; (3) "The Roots of a Semiotic Perspective: C. S. Peirce and Semiosis"; (4) Critical Thinking in Semiotic Perspective: A Process of Inquiry"; (5) "The Practice of Critical Thinking"; and (6) "Classroom Contexts for Critical Thinking." Forty-nine references and an annotated bibliography derived from searches of the ERIC database are attached. (MS)