This article explores Joseph Raz's concept of exclusionary reasons and attempts to explain how this concept fits into a general account of the authority of law. That account is elucidated and the concept of exclusionary force is considered in some detail. The article suggests that if 'exclusion' is read in a strong sense, it is extremely difficult to find examples of its existence. If though it is read in any weaker sense, it appears indistinguishable from the idea of 'weight'. The (...) article also considers the phenomenological, functional and ultimately, the existential reasons in favour of saying, as Raz does, that all legal authorities make their claims to authority in terms of exclusionary reasons. It is argued that this is both unlikely and unnecessary. The curious nature of exclusionary reasons is hence thoroughly unearthed. (shrink)