...snip...
So you don't own you, then. So who does? As noted above, someone owns you. Either you own you, or society does; so which is it? Are you your own, or are you slave to the collective? It pretty much answers itself, because there can be no middle ground.
Is slavery allowed?
If yes and you are free, then you own yourself. If yes and someone owns you, well then someone owns you.
If slavery is not allowed, since you can't sell yourself and since society can't sell you, then you don't have an owner. You are truly free.
Slavery is not allowed under libertarian ideals, because no one can own you but you. However, you can sell yourself, lease your time, or even kill yourself; because the fundamental concept of ownership is the right to destroy, not to utilize.