Although the importance of literacy is widely acknowledged in society and remains at the top of the political agenda, writing has been slow to establish a place in the cognitive sciences. Olson argues that to understand the cognitive implications of literacy, it is necessary to see reading and writing as providing access to and consciousness of aspects of language, such as phonemes, words and sentences, that are implicit and unconscious in speech. Reading and writing create a system of metarepresentational concepts that bring those features of language into consciousness as a subject of discourse. This consciousness of language is essential not only to acquiring literacy but also to the formation of systematic thought and rationality. The Mind on Paper is a compelling exploration of what literacy does for our speech and hence for our thought, and will be of interest to readers in developmental psychology, cognitive science, linguistics, and education.