The document discusses the concepts of altruism and solidarity in organ donation. It analyzes these concepts from both an Aristotelian perspective and using the principles of biomedical ethics. While solidarity is sometimes defined as involving reciprocal duties and obligations (RDO), the document argues that "altruistic solidarity" is a better conception that does not impose requirements on organ recipients. It concludes that understanding solidarity as RDO is inconsistent with international principles of organ transplantation and basic human rights.