How Libertarians Can Deal with Voluntary Slavery

I’ve been reading some left-libertarian stuff recently and had this random thought about voluntary slavery. Briefly, left-libertarianism is the view that people are full self-owners (in the same sense as right-libertarians like N0zick or Rothbard), but the natural world is either equally owned or appropriation of natural resources is subject to a proviso at least as strict as Locke’s.

Left-libertarianism is an interesting view that tries to combine the appeal of libertarian self-ownership while jettisoning the inegalitarian implications of some right-libertarian views. Left-libertarians, like all libertarians who accept full self-ownership, accept that people have a moral power to transfer their rights over their persons to others, which is consistent with voluntary slavery.

A lot of people think a decisive objection to libertarianism is that it permits voluntary slavery. But it seems like there’s a way for libertarians to get around the voluntary slavery problem.

Suppose A is in a relationship with B that’s not going well. A asks C to have sex. Suppose A voluntarily waives her right against nonconsensual sex with C. We’re assuming that A has voluntarily agreed to have sex with C, and that C would not violate A’s rights by having sex with A.

Nevertheless, C could still have a duty not to have sex with A. It could be a duty to B, or maybe an impersonal duty not to undermine relationships. The point is that there are cases where we might have duties *not* to do things people voluntarily allow us to do.

It seems like the libertarian could say this about the voluntary slavery case. People have rights to sell themselves into voluntary slavery, but the new slaveowner has a duty not to enforce or honor the slave contract.