The one on slavery really made me think - and I've thought about this quite a bit before obviously.
You can't have a free society (i.e. absolute self-ownership) without the
right to contract, which includes the possibility of signing yourself into
indentured servitude. A loan contract you might sign might have this remedy in case of
default, and it is very likely to be a big part of a restitution-based legal system.
The fundamental difference is that in a free society indentured servitude can't be imposed on someone based on race or any other distinction, nor can it ever be imposed by force - the most obvious violation of one's self-ownership, the (negative) right to liberty. And it cannot pass from generation to generation.