In philosophy, moral responsibility is the status of morally deserving praise, blame, reward, or punishment for an act or omission, in accordance with one's moral obligations. Deciding what (if anything) counts as "morally obligatory" is a principal concern of ethics.
Philosophers refer to people who have moral responsibility for an action as moral agents. Agents have the capability to reflect on their situation, to form intentions about how they will act, and then to carry out that action. The notion of free will has become an important issue in the debate on whether individuals are ever morally responsible for their actions and, if so, in what sense. Incompatibilists regard determinism as at odds with free will, whereas compatibilists think the two can coexist.
Moral responsibility does not necessarily equate to legal responsibility. A person is legally responsible for an event when a legal system is liable to penalise that person for that event. Although it may often be the case that when a person is morally responsible for an act, they are also legally responsible for it, the two states do not always coincide.
Depending on how a philosopher conceives of free will, they will have different views on moral responsibility.
Metaphysical libertarians think actions are not always causally determined, allowing for the possibility of free will and thus moral responsibility. All libertarians are also incompatibilists; they think that if causal determinism were true of human action; people would not have free will. Accordingly, libertarians subscribe to the principle of alternate possibilities, which posits that moral responsibility requires that people could have acted differently.