All living beings are vulnerable throughout their life span to the effects of biology and environment, such as disease, natural disaster, and war. Vulnerability is thus a shared and constant state among living beings (Fineman 2008, 2010) that cuts across social, geographic, and species boundaries (Satz 2009). The all-encompassing nature of vulnerability, however, is often overlooked. Vulnerability frequently is discussed in social science, public health, and other disciplines in terms of particular characteristics of individuals that render them members of “vulnerable populations.” Women, children, racial minorities, prisoners, elderly persons, and individuals with disabilities all have been viewed as members of vulnerable populations because they may be subject to exploitation, discrimination, or other harm. This perspective confuses vulnerability—which all living beings share—with the fact that some individuals may (or may not) experience vulnerability more acutely than others.