A purpose of this book is to provide a thoroughly readable in-depth review of recent findings and theories about the development of understanding mind. In preparing this, a major goal was seen as composing text that is appealing in itself as a piece of writing. The book covers development from infancy to adulthood, and also considers related disorders of development (especially autism). It goes beyond the narrow focus on the preschool years typical of most writings on the topic. One of the main themes in the book concerns the role of language and communication in development. Language could serve as a tool that helps the child to think more in the abstract and hypothetical, once removed from reality. Being able to communicate with language virtually means that we are able to hear the thoughts of those around us. We hear what they think from what they say. Communication could thus provide a major catalyst in promoting the development of an understanding of mind.