Human beings are the only species in nature to have developed an elaborate division of labor between strangers. Even something as simple as buying a shirt depends on an astonishing web of interaction and organization that spans the world. But unlike that other uniquely human attribute, language, our ability to cooperate with strangers did not evolve gradually through our prehistory. Only 10,000 years ago - a blink of an eye in evolutionary time - humans hunted in bands, were intensely suspicious of strangers, and fought those whom they could not flee. Yet since the dawn of agriculture we have refined the division of labor to the point where, today, we live and work amid strangers and depend upon millions more. Every time we travel by rail or air we entrust our lives to individuals we do not know. What institutions have made this possible? In The Company of Strangers, Paul Seabright provides an original evolutionary and sociological account of the emergence of those economic institutions that manage not only markets but also the world's myriad other affairs.