 Identity is often said to be a relation each thing bears to itself and to no other thing (e.g., Zalabardo 2000). This characterization is clearly circular (“no other thing”) and paradoxical too, unless the notion of “each thing” is qualified. More satisfactory (though partial) characterizations are available and the idea that such a relation of absolute identity exists is commonplace. Some, however, deny that a relation of absolute identity exists. Identity, they say, is relative: It is possible for objects \(x\) and \(y\) to be the same \(F\) and yet not the same \(G\), (where \(F\) and \(G\) are predicates representing kinds of things (apples, ships, passengers) rather than merely properties of things (colors, shapes)). In such a case ‘same’ cannot mean absolute identity. For example, the same person might be two different passengers, since one person may be counted twice as a passenger. If to say that \(x\) and \(y\) are the same person is to say that \(x\) and \(y\) are persons and are (absolutely) identical, and to say that \(x\) and \(y\) are different passengers is to say that \(x\) and \(y\) are passengers and are (absolutely) distinct, we have a contradiction. Others maintain that while there are such cases of “relative identity,” there is also such a thing as absolute identity. According to this view, identity comes in two forms: trivial or absolute and nontrivial or relative (Gupta 1980). These maverick views present a serious challenge to the received, absolutist doctrine of identity. In the first place, cases such as the passenger/person case are more difficult to dismiss than might be supposed (but see below, §3). Secondly, the standard view of identity is troubled by many persistent puzzles and problems, some of recent and some of ancient origin. The relative identity alternative sheds considerable light on these problems even if it does not promise a resolution of them all.