In Part I of this book, by reporting on our own research and reflecting on the writings of others, we offer evidence of the changes that the professions are facing. In these opening chapters, however, we do not provide an explanation of why this transformation is taking place. That is our purpose now, in Part II of the book. Our aim is to provide a more general and systematic account of what is going on. We advance a variety of theories and models that explain the evidence we have uncovered and suggest how these may help us predict what is yet to unfold. Our initial focus in this chapter is on what we call the ‘information substructure’ of society, and how this influences the way that human beings have shared practical expertise in the past and are likely to do so in the future. Then we turn to technology, and talk about the worth of making predictions. Our conclusions here help us to identify what we regard as the four most important sets of future developments in technology. In concluding this chapter, we present a fifty-year overview of the changing impact of technology on the professions. This then sets us up for Chapter 5, where we discuss the nature of knowledge, the evolution of professional work, and the models for the production and distribution of practical expertise that will displace the traditional working practices of professionals. In everyday conversation, people often now use the terms ‘technology’ or ‘tech’ more often than ‘information technology’ and ‘IT’. This emphasis on the technical angle is understandable, because the technological accomplishments that underpin our everyday devices are remarkable. The technology can be mesmerizing, both in its power and design, and we justifiably marvel at the genius and ingenuity of those who contribute to its development. But to focus exclusively on the ‘T’ rather than on the ‘I’, to neglect the ‘information’ in our wonder at the ‘technology’, runs the risk of failing to grasp the role and value of information—in our world generally, and especially in the professions.