Directed at students of cognitive development at all levels, this book presents three themes which are central to Piaget's description of cognitive development, but which students often fail to appreciate. In the first three chapters the themes are introduced and illustrated with reference to Piaget's empirical findings. The next chapter presents examples of ways in which some of the themes have received insufficient attention in the psychological literature on Piaget's theory. This chapter, giving the author's reinterpretation of many of the most famous 'anti-Piaget' findings in the literature, is probably the most controversial part of the book. The final chapter discusses the themes attractive features and problems.