This work presents a contextual theory of the moral status of animals which combines the demands of impartiality and the significance of relationships of vulnerability and partiality. From an analysis of the notion of moral status as a set of obligations directly owed to animals, a two-fold theory is spelled out: a descriptive model and a normative model of moral status attribution, which are both "dual": moral status depends on both intrinsic and extrinsic properties of morally considerable entities (typically, capacities on the one hand, relationships and context on the other hand). The normative model is built around two core principles : a Principle of Protection of the Vulnerable and a Principle of Reasonable Partiality, which are both...