I began this book with a reflection on the relationship between freedom and power. I hope the subsequent chapters have made it clear that I, like Hayek, regard the rule of arbitrary power as being not only at odds with individual liberty, but also as deeply injurious to the epistemic exchanges and collaboration upon which a successful economy is based. It should, however, also be apparent that, unlike him, I want to insist that we must consider the ways in which arbitrary private power, dominium, as well as arbitrary public power, imperium, undermines freedom and frustrates the fullest use of knowledge in society.