Originally published in 1995, this book is about the conduct of cognitive science rather than what cognitive science is. It has three main objectives. First, it describes the birth of cognitive science. Second, it outlines the method of enquiry which characterises and defines cognitive science. This method uses the techniques of artificial intelligence based on the assumption that mental activity can, in principle, be reproduced by a computer program. Third, the book describes the state of the art in relevant areas, with particular attention to application fields such as pedagogics, human–machine interaction, and psychotherapy. The developmental approach is emphasised and highlights the fact that developmental aspects are essential in order to comprehend the steady mode of functioning achieved once a person has reached total maturity. Cognitive science is not presented as a definitive method for the analysis of the mind, though the author’s conclusion is that it is the best of all possible methods today. At the time of publication this book would have been useful as an advanced textbook for students on courses specialising in cognitive science, and as a source of further information for those working in related areas such as cognitive psychology, linguistics, and computer science. It will still be of interest to experts and students in the field of cognitive science.