Where does normativity come from? Or alternatively, in virtue of what do facts about what an agent has reason to do obtain? On one class of views, reason facts obtain in virtue of agents’ motivations. It might seem like a truism that at least some of our reasons depend on what we desire or care about. However, some philosophers, notably Derek Parfit, have convincingly argued that no reasons are grounded in this way. Typically, this latter, externalist view of reasons has been thought to enjoy the advantage of extensional adequacy—that is, the ability to account for all the reasons we intuitively think people have. This paper provides a novel argument against this assumption by considering a type of case wherein the relative strengths of the...