In a context of disciplinary division between human and physical geography, the book seeks to reassert the unity of the field through an emphasis on a shared focus on the geographic configuration of things and how and why configuration is important. It first examines previous approaches to reestablishing unity, and why they have failed, before moving on to an explanation of fundamental differences in what is being studied and how. The role of configuration looms large in both. This is in the sense of contingency and the idea of emergence, suggesting that reconstruction of unity can proceed through an exchange of models of understanding. This book will appeal to those teaching courses or seminars in geographic thought or in the history of geographic thought.