Trust is a constituent component of social life: societies capable of building and developing norms and relations underpinned by trust - ranging from the sharing of food among hunter-gatherers to internet transactions in the modern age of dot.com economies - have enjoyed, more than others, the benefits deriving from the division of labour and complex organisations. Without trust we would fall into conditions similar to those of Hobbes's state of nature, with "no arts, no letters, no society" and "continual fear, and danger of violent death". Trusting one another implies, first of all, establishing an interpersonal relationship and, within this relationship, working together to achieve a state of affairs that is preferable to the status quo. But the opportunity for improvement is offset by the risk of betrayal of trust: Trust equals risk. So is trust nothing more than a wager? Not at all, for trusting someone is indeed a risk, but it also involves laying the foundations for reliable reactions. Trusting others, in fact, leads these others to be more reliable, thus engendering a paradox: trust equals reducing the risk of betrayal. Through economic analysis, philosophy, the history of ideas, and psychology, Pelligra's book explores the significance of this paradox for the understanding and the regulation of economic and social phenomena in general.

Vittorio Pelligra teaches Advanced Microeconomics, Games Theory, and Welfare State Economics at the University of Cagliari, as well as Games Theory and Organisations at the University of Milan-Bicocca.