Originally published in 1971, this book constitutes a scientific enquiry into the basis of reading, and dyslexia. Professor Vernon considers visual perception, reasoning, motivation, and outlines work in psycholinguistics in order to define the basic psychological processes involved in learning to read. She also discusses the problem of specific developmental dyslexia, and concludes that the basic deficiency may lie in the processes of conceptual reasoning between the sequence of printed and 'sounded' letters. A fundamental disfunction of the brain is also seen as a possibility. She stresses the importance of early recognition and remedial treatment of reading difficulties, since these may be alleviated, if not entirely overcome, by suitable treatment.