This chapter provides an introduction to the motives, nature, and structure of criminal thinking. The principal motive behind criminal thinking is self-protection. There is a need to justify one’s actions, particularly when these actions violate societal norms, laws, and morays. Criminal thinking provides such protection by way of self-serving bias. Secondly, the nature of criminal thinking in relationship to criminal behavior is that while it often arises in support of criminal activity, it can also precede such activity. To a large extent, then, the relationship between criminal thinking and criminal behavior is bidirectional. Thirdly, all criminal thinking is structured or organized around a false premise. A false premise is an untrue proposition that in many cases leads to an erroneous conclusion. Each criminal thinking style, it is argued, is based on a different false premise, and each false premise is the product of denial and defensiveness. As the first chapter of Part II of this book, Chapter 5 provides a synopsis of the remaining seven chapters.