Authority, trust, legitimacy: we spontaneously feel these are central to the proper functioning of society, and yet our notions of them can be terribly vague. This book sets out to retrace the history of these ideas and to understand them as invisible institutions. Institutions, because their function is to produce the commons and make political, social, and economic relationships sustainable. But invisible, because they are not defined by rules and statutes. nor are they endowed with the ability to constrain behavior. This conceptualization allows a broadening of perspectives helpful to overcoming the intellectual bafflement and stunted imagination that today's populist mirages prey on.