Why bioethics needs a concept of vulnerability

Vulnerability is often defined as being at increased risk or harm, and/or having a decreased capacity to protect oneself from harm. Bioethics frequently addresses people's risk of harm to health, to well-being or autonomy, and so concern for human vulnerability is ubiquitous in bioethical discussion. Common approaches in bioethics, such as principlism, ethics of care, virtue ethics, and so forth, all focus upon potential harms incurred by practices such as health care or participation in research, and try to determine the moral responsibilities and duties of all involved. Vulnerability appears to be at the heart of bioethics. But if this is the case, then we need an adequately theorized conception of vulnerability that can be used to assess or justify the interventions and practices invoked in the name of protecting the vulnerable.