128 HARVARD LAW REVIEW. France and in England we may find in very ancient days, A man will sometimes receive money to the use {ad opus) of another person; in particular money is constantly being received for the king's use. Kings must have many ministers and officers who are always receiving money, and we have to distinguish what they receive for their own proper use {ad opus suuni prop.rhini) from what they receive on behalf of the king. Further, long before the Norman Conquest we may find a man saying that he conveys land to a bishop to the use of a church, or conveys land to a church to the use of a dead saint. The difficulty of framing a satisfactory theory touching the whereabouts of the ownership of what we may loosely call ' the lands of the churches ' (a difficulty that I cannot here pause to explain) gives rise to such phrases. In the thirteenth century we commonly find that where there is what to our eyes is an informal agency, this term ad opus is used to describe it. Out- side the ecclesiastical sphere there is but little talk of ' procura- tion ' ; there is no current word that is equivalent to ouv agent ; John does not receive money or chattels ' as agent for ' Roger ; he receives it to the use of Roger {ad opus Rogeri). Now in the case of money and chattels a certain haziness in the conception of ownership, which I hope to discuss elsewhere, pre- vents us from making a satisfactory analysis of the notion that this ad opus implies. William delivers two marks or three oxen to John, who receives them to the use of Roger. In whom, we may ask, is the ownership of the coins or of the beasts } Is it already in Roger ; or, on the other hand, is it in John, and is Roger's right a merely personal right against John .-* In the thirteenth century this question does not arise in a clear form, because possession is far more important than ownership. We will suppose that John is the bailiff of one of Roger's manors, that in the course of his business he has gone to a market, has sold Roger's corn, has pur- chased cattle with the price of the corn and is now driving them home. We take it that if a thief or trespasser swoops down and drives off the beasts, John can bring an appeal or an action and call the beasts his own proper chattels. We take it that he him- self cannot steal the beasts ; even in the modern common law he can not steal them until he has in some way put them in his em- ployer's possession. We are not very certain that if he appropri- ates them to his own use Roger has any remedy except in an action of debt or of account, in which his claim can be satisfied by a money payment. And yet the notion that the beasts are Roger's,
