This chapter aims to show that vulnerability is a deceptively complex phenomenon that means different things to different people. In doing so, it explains how vulnerability is variously viewed as an elemental human condition that is associated with human frailty and risk and as a phenomenon that is a product of factors that lie external to individuals, such as insufficiencies, inequities and flaws in people’s social, economic and geographic environments. It demonstrates how definitions of vulnerability differ across operational spheres and explains that vulnerability is sometimes treated as a subjective phenomenon that can only be understood from the perspective of the individual and at other times, an objective phenomenon that can be directly measured and assessed. The text also shows that vulnerability is a uniquely human entity that flows from our advanced cognitive facilities and contrasts this with the physical experience of fear and vulnerability found in other species of animal. Following this, the text examines whether vulnerability is best viewed as a fixed entity that resides within individuals or as a complex, dynamic entity that arises from personal dispositions and external pressures. In doing so, it explores vulnerability as a condition humana and shows how in many cultures and religions, vulnerability is viewed as an elemental human condition that builds character and empathic understanding. It contrasts this with contemporary Western culture where vulnerability has become equated with personal weakness and victim-blaming associated with the belief that conditions like poverty and employment are predicaments of people’s own making. The text then looks at why we are both fascinated and repelled by our own vulnerability, and it explains how in coming to view vulnerability as a sign of personal weakness, we have developed a predilection for simplistic models that shy away from connecting human vulnerability with factors, such as child maltreatment and socio-economic deprivation. The chapter concludes by considering the psychological mechanisms that we use to manage angst arising from knowledge that we are all mortal beings who reside in a world that is fraught with constant risk and danger.