The concept of vulnerability in law

This article clarifies the legal concept of vulnerability by reconstructing its conceptual structure, rather than defending a substantive theory of justice. I advance three claims. First, vulnerability is a thick (non-essentially evaluative) concept: it retains a descriptive core while being routinely used to support normative and institutional conclusions in legal reasoning. Second, vulnerability is not an essentially contested concept in Gallie’s sense. Disputes about its use in law are better explained as practice-bound disagreements about application conditions and evidentiary standards, as opposed to competitions over a single internally complex value. Third, vulnerability in law is best understood as a cluster concept. Its correct application is not fixed by one definition but by an interconnected set of doctrinal and institutional propositions that coordinate (i) triggering conditions (forms of exposure to risk or harm), (ii) markers of heightened susceptibility and dependency, and (iii) characteristic legal consequences such as protected status, strengthened duties of care, procedural accommodations, and facilitated access to remedies. On this reconstruction, legal vulnerability is relational, graded, and context-sensitive, yet conceptually stable: the concept can remain the same even as legal systems incorporate new sources of risk and harm. The payoff is practical. A cluster-based reconstruction helps courts and scholars distinguish between merely rhetorical invocations of ‘vulnerability’ and uses that carry determinate legal implications, thereby improving conceptual clarity and making vulnerability-based arguments more transparent and contestable.