A person finds a lost purse with a lot of money in it. Ought she try to return it to its owner or keep it herself? And even more interestingly, what will she actually do? According to standard economic theory, a rational person is supposed to maximize her utility and, at least when unobserved, keep the purse for herself. In reality, however, most people return the purse although they are unobserved or, at least, they feel uneasy about not doing so. Evidently, these people share a common attitude towards other people's property. In social life, norms and values like this typically help in settling potential conflicts of interest to the mutual benefit of all. While not evident immediately, social norms and values play a crucial role in the theory of social choice. In the first half of the twentieth century, the special acknowledgement by economic theory of the autonomy of individuals and their subjective view of the world had led to the serious problem that socially acceptable decisions could not be made in the absence of unanimity. In this work, social norms and values are reintroduced to overcome this shortcoming by applying a common standard and, thus, making individua preferences comparable. In particular, it is shown, how the adoption of these standards is part of every individual's social development, how the standards themselves arose in the course of social evolution and how human beings were endowed with the necessary learning mechanism by Darwinian evolution in the first place. This impressive, unique book is well informed and clearly written. It will be of great interest to all those students, academics and researchers who are interested in evolutionary economics as well as social welfare and philosophy.