Property' is a Relative Concept
Since the physical, legal and moral conditions of excludability may vary according to time and circumstance, it becomes clear that the notion of "property" in a resource is not absolute, but relative. The concept of "property" is not static, but dynamic. I may have "property" in a resource today, but not tomorrow. I may have "property" in a resource for one purpose but not for another. I may have "property" in a resource as against X but not necessarily as against Y or Z. It may be that P and Q can both claim "property" in the same resource although their respective interests are mutually opposed. It is not even inevitable that there should be a quantum step between having "property" in a resource and not having "property" in it. Propertiness is represented by a continuum along which varying kinds of "property" status may shade finely into each other.