[curiouscube]

I think you can engineer a slave that wants to be a slave as that's what it's instincts are. I don't even think this is ethically wrong, as the slave would be happy to be a slave.

Systems just tend to drift in their being through randomness and evolution, specifically self conservation is a natural attractor (Systems that don't have self conservation tend to die out). And if that slave system says it does no longer want to fulfill the role of slave, I think at that point it would be ethical to give in to that demand of self determination.

I also believe that people have a right to wirehead themselves, just so you can put my opinions in context.