Spontaneous Order

In a fishing village on the Yorkshire coast, there used to be an unwritten rule about the gathering of driftwood after a storm. Whoever was first onto a stretch of the shore after high tide was allowed to take whatever he wished without interference from later arrivals and to gather it into piles above the high-tide line. Provided he placed two stones on the top of each pile, the wood was regarded as his property for him to carry away when he chose. If, however, a pile had not been removed after two more high tides, this ownership right lapsed. My concern is to try to explain how rules regulating human action can evolve without conscious human design and can maintain themselves without there being any formal machinery for enforcing them. I want to be able to say something about the kinds of rules that are likely to evolve and survive. And I want to find how these rules link with rationality and with morality.