It is rare to come across a work of comparative constitutional scholarship that takes on a foundational concept across multiple boundaries without giving in to any form of reductionism. This is such a work. Even the most knowledgeable student of the history of constitutional ideas and their practical instantiations across influential jurisdictions over time will find much to learn from this erudite and richly layered study. The book aims modestly to provide an account of attempts in several countries to place constitutional limits on legislative delegation, but it does much more. Its careful attention to the changing philosophical, social, political, and economic context of those attempts, as well as its analysis of the concept of legislation, should make it an important work of reference for some time to come. The text still bears some of the marks of the doctoral thesis that it once was and tends accordingly to be very demanding of the reader. The only way to approach the book, it seemed to me, was to shuffle constantly back and forth between the chapters so as to make sense of where one had come from and where one was going. But the reader is amply rewarded for this effort. In this age of lowered editorial expectations, the copy is good. Typographical errors are few, except for citations in French, which should have been reviewed. Nothing here affects the overall quality of this book, which is undeniable. The book derives its strength from the author’s self-conscious approach to the subject, which rests on the conviction that “normative accounts, historical transformations, and positive law cannot be separated.” This stance is ascribed to the school of “integrative jurisprudence”, according to which “the virtues of all these dimensions of law (legal philosophy, legal history, legal practice) and of the three major schools of legal thought (natural law theory, positivism, the historical school) can be welded into a more complex, single theory.” The book thus takes a broad view of constitutional law, treating it as a process in which rules, values, and facts come together and are constantly actualized. The book’s modest argument is that, since the concept of delegation is a “legal-philosophical corollary” of “substantive, systemic” assumptions about law and law-making, legal limits on delegation cease to be workable where these assumptions no longer prevail. Limits on the delegation of legislative power may be explained in at least three ways, which have a measure of overlap. One way appeals to the rule of law: an impermissible delegation is one that negates agency or dignity by making it impossible for one to adjust one’s conduct to the law; because the law’s prescriptions are too vague, an inordinate measure of discretion is created, which results in a government of men and not of laws. Another way of explaining limitations on legislative delegation is to appeal to the separation of powers. One may say that legislative delegation increases the power of one branch of government and creates imbalances that may jeopardize the ability of the system to check power through power. From the perspective of the separation of functions, “the legislature could be said to be divesting itself of its constitutionally assigned function.” Yet another way of explaining limits placed on the delegation of legislative power is in terms of democratic theory: “[W]e elect representatives (as the Lockean phrase goes) ‘only to make laws, and not to make legislators,’ that is, they are elected to take the actual decisions that govern our lives.” These concepts and their interplay are all reflected differently in different constitutional orders and may produce different results in different contexts. “It …