 Raz proposes a system of practical rationality with two sorts of reasons, of first and second order. First order reasons are reason for or against courses of action, while second order reasons are reasons about reasons themselves. Exclusionary reasons are second order reasons that exclude other, first order reasons. Promises, says Raz, produce (in the promisor) both first order reasons to perform the promised act as well as second order exclusionary reasons to bar from considerations most first order reasons that counsel against keeping the promise.