If promises are binding there must be a reason to do as one promised. The paper is motivated by belief that there is a difficulty in explaining what that reason is. It arises because the reasons that promising creates are content-independent. Similar difficulties arise regarding other content-independent reasons, though their solution need not be the same. -/- Section One introduces an approach to promises, and outlines an account of them that I have presented before. It forms the backdrop for the (...) ensuing discussion. The problems discussed in the paper arise, albeit in slightly modified ways, for various other accounts as well. It is, however, helpful to use a specific account as a springboard leading to one explanation of promissory reasons, namely of the reasons that valid promises constitute for performing the promised act (Section Two). We can call it the bare reasons account. Sections Three and Four will raise difficulties with that account, leading to its abandonment in favour of an alternative in Sections Five and Six. (shrink)