Purely Instrumental Agents Are Possible

Purely instrumental agents can reason about how to realize their ends, but not about which ends to pursue. They can do one thing in order to do another but cannot choose their final ends for reasons. Some have argued that such agents are impossible, and that the success of moral constitutivism depends on their impossibility. Moral constitutivists hope to ground moral norms in the nature of rational agency as such. But if purely instrumental agents are possible, then rational agency is too thin to ground moral norms. I argue that purely instrumental agents are possible, but their possibility by itself does not refute moral constitutivism. Moral constitutivists might embrace a pluralist form of constitutivism, according to which practical norms for an agent are grounded in the nature of her kind of agency, not in the nature of rational agency as such. This pluralist variant of constitutivism, however, faces problems of its own. I leave open whether pluralism fares any better overall than extant versions of moral constitutivism.