A good question to ask is, “If you don’t own yourself, who does?”
However, self-ownerhip is not merely an ethical axiom, but a statement of self-evident fact. Indeed, the self is the only thing our ownership of which is absolute, and totally inalienable. The only person who has direct control over the person (the body, the mind, etc.) is the individual, himself. However much one might desire another to take, or refrain from taking, a particular action; however hard one tries to influence another’s decision; however much one screams, threatens, even causes direct physical harm and pain (torture), the ultimate decision as to one’s action rests with the individual, himself. An outsider can only structure incentives as best he knows how… or kill, if the desire is a negative.
However, the consequences of action do not rest within the individual, but without. (Even something like the consequences of our choices as to what to put inside our bodies are outside our control.) The consequences of any action cannot be truly known until the act is taken, though our reason allows to extrapolate from experience the likely consequences. One may have superior judgment than another under certain circumstances, but the truth of who has better judgment than who can be determined ONLY by allowing the action in question to be taken (or not taken, as the case may be), and observing the results. In religious terms, God is the final judge in all matters.
Accepting that this ownership extends from the individual himself to the consequences of his action is nothing more than another way of saying that others should be required to take responsibility for their actions. Consequences can be positive or negative, and among the consequences of a man’s actions are the fruits of his labors. In fact the individual owns those consequences, quite literally, until another individual takes an action which ameliorates or deprives him of those consequences (negative or positive). Among the consequences of a person’s actions is the increased utility of physical matter: wealth. “Property” is nothing more than the recognition that it is proper to leave those consequences in the hands of the one who brought them about.
I reiterate: self-ownership is is nothing more than the fact that the final decision is always in the hands of the individual (whether you like it or not), and property is nothing more than that moment before outside intervention when the consequences of an action rest in the hands of the actor. No oath, contract, or other declaration or social construct can invalidate this fact. If one declares that he belongs to another, he can honor this if he likes (and it might even be a good idea to do so), but nothing can deprive him of the power of going against his “master’s” wishes.
If your friend makes reference to the status quo as an example of the consequences of adherence to this ideal, you must vigorously disagree. Under the status quo, the flow of wealth is, at many points, by many means both subtle and blatant, diverted from those who produced it, to others. Redistributive taxation is NOT the only mechanism and, the power ethic functioning as it does, the diversion is largely from weaker to stronger. The solution is not to seize and redistribute along arbitrarily determined lines (remember, it is the powerful who are the best at seizing, and thus most likely to benefit), but to study the problem diligently and ferret out specific injustices. Some of them are obvious and individual in character (plain old theft). Others are systematic, the result of a society-wide acceptance of practices and institutions hostile to a sound link between an individual’s actions and their consequences.