Is the state a collective agent? Are citizens responsible for what their states do? If not citizens, then who, if anyone, is responsible for what the state does? Many different sub-disciplines of philosophy are relevant for answering these questions. We need to know what “the state” is, who or what it's composed of, and what relation the parts stand in to the whole. Once we know what it is, we need to know whether that thing is an agent, in particular a moral agent capable of taking moral responsibility for its actions. We have to know what it takes for it to be capable of moral responsibility, e.g., what the functional equivalents in groups are of knowledge, intention, foreseeability, recklessness, and so on. And once we've established that it is an agent, and is responsible for what it does, we have to explain whether and in what way this implicates members, i.e., whether state responsibility distributes to the members of states, whoever they may be. Answers to these questions come from metaphysics, social ontology, action theory, epistemology, political theory, and ethics. In what follows, we'll give an outline of some different ways of answering these questions.