Property-based models of the ownership of body parts are common. They are inadequate. They fail to deal satisfactorily with many important problems, and even when they do work, they rely on ideas that have to be derived from deeper, usually unacknowledged principles. This article proposes that the parent principle is always human dignity, and that one will get more satisfactory answers if one interrogates the older, wiser parent instead of the younger, callow offspring. But human dignity has a credibility problem. It is often seen as hopelessly amorphous or incurably theological. These accusations are often just. But a more thorough exegesis exculpates dignity and gives it its proper place at the fountainhead of bioethics. Dignity is objective human thriving. Thriving considerations can and should be applied to dead people as well as live ones. To use dignity properly, the unit of bioethical analysis needs to be the whole transaction rather than (for instance) the doctor-patient relationship. The dignity interests of all the stakeholders are assessed in a sort of utilitarianism. Its use in relation to body part ownership is demonstrated. Article 8(1) of the European Convention of Human Rights endorses and mandates this approach.