<p>Wilfrid Sellars’ image of the space of reasons provides a valuable way of envisioning agency, and particularly, of envisioning the special way that agency can be interpreted and explained. This paper seeks to determine what sort of reason constitutes the space of reasons, that is, what sort of reason makes this special form of interpretation and explanation possible. Because the space of reasons enables us to explain agents’ errors, we would seem to need reasons that obtain even when agents are mistaken about their normative situations. This points in the direction of reasons that are subjective, in the sense that they arise within agents’ minds. But by drawing on Donald Davidson’s principle of charity, which governs the interpretation and explanation of agency, we can show that the space of reasons is constituted by mind-independent normative reasons. Moreover, by drawing on Davidson’s externalism, we can show that normative reasons are real and that they command causal power.</p>