Anglo-American private law has been a far more complex phenomenon than has been usually recognized. Attempts to reduce it to a single explanatory principle, or to a precisely classified or categorized map, scheme, or diagram, are liable to distort the past by omitting or marginalizing material inconsistent with proposed principles or schemes. This study will be of importance to all who are interested in property, tort, contract, unjust enrichment, legal reasoning, legal method, the history of the common law, and the relation between legal theory and legal history.