This book helps to explain what we mean when we say that an issue, a question, or a situation is a matter of "judgement". Author F.H. Low-Beer opens a new window on cognition by examining judgement as exercise, an aspect not previously attempted in a systematic way. Problems ordinarily dealt with in practical reasoning, decision theory, and interpretation are examined here in a fascinating new light. Beyond its new theoretical insights, the singular contribution of this book lies in its examination of the overlooked place of judgement in the everyday world. Low-Beer looks at what is foundational in society, the courts, the professions, politics, and commerce fields of practice with which he is very familiar and concludes that the exercise of judgement is a defining characteristic of professionalism. The author's interdisciplinary approach will nudge readers of philosophy, legal and political theory, as well as decision theory to connect the academic with the wider world.