Abstract: Using the concept of purposeful action, I define the necessary and sufficient aspects of any property. These qualities are derived though noticing that property is those things which are the object of a set of past, present, and future actions of individuals. The result is that property is the result of a change in the physical world which lends itself to control and is expected to grant a future value to the actor. By deconstruction, these qualities are used to show that aggression upon another actor is equivalent to a property claim in that other actor, enforcement of a property claim may involve an aggression, and conflicting aggressions may only be compared subjectively. Thus the novel concept of net coercion is introduced to delineate which actors are making an over-reaching property claim. This incorporates the common term of aggression as used by modern libertarian theorists, but allows for a further analysis when there are conflicts of possible or perceived aggressions; certainly attempting to minimize the net coercion of a system of actors is equivalent to the special case of striving for zero-aggression. After establishing the value-free concepts that entail property regimes I define the seeking of justice as trying to minimize the net coercion of any system. From this single necessary definition of justice, a number of problems are analyzed including the stereotypical commons, a construction equivalent to hostile encirclement, and claims of property in intellectual creations. The ultimate conclusion of this analysis is that property regimes with a positive net coercion are unjust and equivalent to property claims in the individual actors subject to the more aggressive actors, in essence, that they are the chattel slaves of the dominant actors in proportion to the amount of net coercion used against them. From these foundations, a philosophical system by which to analyze particular property claims is created and a suggestion of how law and economics should treat property claims is implicit.