The High Court continues to exercise its inherent jurisdiction to make declarations about interventions into the lives of situationally vulnerable adults with mental capacity. In the light of the protective responses of health care providers and the courts to decision-making situations involving capacitous vulnerable adults, this article has two aims. The first is diagnostic. The second is normative. The first aim is to identify the harms to a capacitous vulnerable adult’s autonomy that arise based on the characterisation of situational vulnerability and autonomy as fundamentally opposed concepts or the failure to adequately acknowledge the conceptual relationship between them at common law. The second (normative) aim is to develop an account of self-authorised, intersubjective autonomy based on insights from analytic feminist philosophy. This approach not only attempts to capture the autonomy of capacitous vulnerable adults and account for the necessary harms to their autonomy that arise from standard common law responses to their situational vulnerability, it is also predicated on the distinctions between mental capacity, informed consent, and autonomy, meaning that it is better placed to fulfil the primary aim of the inherent jurisdiction—to facilitate the autonomy of vulnerable adults with capacity.