Political science is a highly diverse field united around a core interest. Political scientists study power, and especially power used for public purposes: how it is created, organized, distributed, justified, used, resisted, and sometimes destroyed. They study power both normatively and empirically. They study it in different settings: within states, among states, and in spaces that states do not (or no longer) control. They consider past as well as contemporary patterns. They use a wide array of approaches and methods to gain leverage on the even wider array of questions they pose