This article explores the nature and role of legal powers in private law. I show how powers are special in that they allow agents to change their (and others’) legal circumstances merely by communicating an intention to do so, without having also to change the nonnormative facts of the world. This feature of powers is, I argue, particularly salient in private law, with its correlative or bipolar normative structure; understanding powers and their role in private law thus requires careful attention (...) to this correlativity. In the final section, I argue that the correct explanation of a variety of substantive problems in private law, many having to do with the role of a party's intention, turns on correctly understanding legal powers. (shrink)