The capability approach provides three important insights to the debate on disability and justice. First, the approach helps resolve some of the tensions in current views of disability, which either emphasize disability as a natural suboptimal trait, or as prevalently socially determined. The approach suggests instead an interactional understanding of disability, where impairment relates to restrictions in functionings, and disability to the consequent limitations in real opportunities. Second, the approach provides a metric of justice which, unlike other metrics such as the Rawlsian social primary goods, is sensitive to the demands of people with disabilities. The potential lower opportunity for well-being of a person with disabilities can only be evaluated in relation to the absence of a certain functioning, and the related inequality in her real opportunities to lead her life fully. Finally, the capability approach, specifically in Nussbaum’s work, advances the discussion on the equal moral and political status of people with disabilities, and cognitive disabilities in particular, by suggesting that their full citizenship is enacted through forms of surrogacy and guardianship when needed, and by defending their human dignity as participants in the human community.