[coldtea]

>Freedom is a binary state

No, it's a continium. Should you be free to have other people as slaves, hurt your children, kill people, burn a forest etc?

If not, then you already drew some limits to freedom.

Yet, I'd venture that a person who "lacks the freedom" to own slaves is still perfectly free.

Never in the history of manking was the concept of freedom understood as this "total binary freedom" you mention. Even tribesmen and such had and respected limits while still considering themselves free folk.