First of all, my rhetorical question (and other discussions at other times) should make clear that I find talk of ownership, rights, etc., among the living and non-living forms on this planet other than humans to be ridiculous and a non-starter (not that this excuses wanton destruction, there are other reasons for not taking a slash and burn approach to the environment).
Well, I'm not trying to argue that animals are property-holding subjects; I was merely pointing out that concepts of property and ownership (as described by Patterson) must either be admitted as fictions, or be capable of extension to nonhuman subjects. If the ownership of one's body is absolute, for instance, it would seem to me that an animal also has absolute ownership of its body. If the response to this claim is then that humans have the ability to conceive of themselves as owners, then we depart from any notion of inherent, or innate ownership, and enter into the realm of ownership as a set of discursive relations (i.e. fictional, or constructed).
Ultimately ownership is going to boil down to an ability to hold. Whether we do that directly via walls and locks and weapons, or indirectly by mutual agreement in a legal and social system. The "justification" as it were is the means to settle disagreement over ownership where one or both parties would wish to avoid dying over it, etc. The idea of ownership (mine!) as well as the ability to recognize when one has been defrauded (theft) is seen in studies of children at an age where they either can't speak or barely can do so. The logic or rationality behind "just" or "rightful" ownership that extends beyond what I hold in my hand at any given time is illusory in the sense that I am said to possess it without holding it in my hand. But it's not "unsubstantiated", and isn't purely a social construct (obviously it is a human construct).
I actually don't think we're on opposite sides here, I just think you expected us to be
. Ownership is unsubstantiated if any individual, at any time, can take someone else's property and declare a new phase of ownership. In such a scenario, ownership ceases to be what it is, which is a right to something beyond one's immediate tactile possession of it (i.e. holding it in your hand).
I'm not trying to say that ownership doesn't exist and that it's a free-for-all. I'm saying that, just as we shouldn't need to justify economic success, or accumulation, by appealing to the free market, we also shouldn't need to justify ownership by appealing to abstract notions of absolute rights in a thing. Rather, we should acknowledge that all property and ownership is the result of necessary violence; but the current cultural mythology of property precludes this.
I'm not saying that you or anyone else is necessarily swayed by this cultural mythology, I'm simply calling attention to it because I wanted to parse it out. To be honest, your response was more rational than I'd expected (also, not implying that you're usually irrational).
I think it's pretty clear that if ownership does simply boil down to what someone can hold on to, then legal and social discourses don't go along with this (which is what Patterson is getting at, partially). Ideological conceptions of property invest a great deal of abstract, absolute rights in objects. "Things are mine because they're mine; yes, I bought them, or yes, I made them - but this has brought about an inherent right to these things that cannot be taken away..." etc. etc.
Ownership is definitely a human construct; but often the explanation for property, or ownership, makes contradictory appeals to something inherent and/or absolute that would automatically include other forms of life, and perhaps even things. So I'm just trying to tease out these complications.