In this paper, I analyse Martha Nussbaum?s view of how we should treat non-human animals, which she links to her capabilities approach. This approach offers a conception of justice or, as Nussbaum puts it, a collection of fundamental rights that specify some of the necessary elements for a just society. In addition to justice for human beings, this approach includes animal rights. The basis for the discussion consists of two elements that justify the claim that every animal deserves to live (...) a life that is characteristic of a member of its species. The first element is dignity, and the second is sympathetic imagination. The intention of Nussbaum?s approach is to represent an improvement on the social contract tradition, by offering a more encompassing theory of justice. In her view, the capabilities approach, contrary to the theories of social contract, has principled resources that allow it to include, among else, non-human-animals in the domain of justice. However, the contribution of my paper consists in showing the problems I observe in Nussbaum?s theory. These problems are related to the insufficient definition of basic concepts and to the fact that in Nussbaum?s theory, non-human animals remain, across various situations, only a means of serving human needs. The consequence is that non-human animals are not included in the domain of justice which, after all, is Nussbaum?s fundamental ambition. (shrink)