http://nkimepx7nuhyzeiy5flekrhwzvuoseowpmxdlu6hw5swqx22qdyhdgqd.onion/contract-theory.html
In short, he cannot, in nature, sell himself into slavery and
have this sale enforced—for this would mean that his future will over
his own person was being surrendered in advance. In short, a man can
naturally expend his labor currently for someone else’s benefit, but he
cannot transfer himself, even if he wished, into another man’s permanent
capital good.