Jacobs raises questions about the increasing popularity of concept of interdisciplinarity, which is becoming a powerful force in American higher education. Reformers assert that blurring the boundaries between traditional disciplines would promote more rapid advances in research, more useful solutions to complex public problems, and more effective teaching and learning. Jacobs maintains that the critiques of established disciplines, such as history, economics and biology, are often over-stated and misplaced. He shows that disciplines are remarkably porous and continually incorporate new methods and ideas from other fields. Drawing on diverse sources of data, Jacobs considers many case studies, including the diffusion of ideas between fields, with a special focus on education research; the creation of interdisciplinary scholarly journals; the rise of new fields from existing ones; American studies programs; cross-listed courses, team teaching and specialized undergraduate degrees. Jacobs broadens the inquiry, looking beyond individual research collaborations to the system of disciplines and the long-term trajectories of research frontiers. Over time, successful interdisciplinary breakthroughs recreate many of the key features of established disciplines. He questions whether efforts to integrate knowledge across domains are likely to succeed, since interdisciplinary research itself is often quite specialized. Finally, these efforts may produce unintended consequences, since an interdisciplinary university would likely promote greater centralization of academic decision making in the offices of deans and presidents. Over the course of the book, Jacobs turns many of the criticisms of disciplines on their heads while making a powerful defense of the enduring value of liberal arts disciplines.