With the ownership of a thing is indeed accompanied the negative right to resist any one who would hinder me from the use of it at pleasure; but a positive right against a person, to demand of him to perform something or to be obliged to serve me in anything, cannot arise from the mere ownership of a thing. It is true this positive right might by a particular agreement be added to the purchase contract whereby I acquire a property from anybody; e.g. that, when I purchase a commodity, the seller shall also send it to a certain place free from expenses. But then the right against the person, to do something for me, does not proceed from the mere ownership of my purchased thing, but from a particular contract.