In very general terms, an agent is a being with the capacity to act, and ‘agency’ denotes the exercise or manifestation of this capacity. The philosophy of action provides us with a standard conception and a standard theory of action. The former construes action in terms of intentionality, the latter explains the intentionality of action in terms of causation by the agent’s mental states and events. From this, we obtain a standard conception and a standard theory of agency. There are alternative conceptions of agency, and it has been argued that the standard theory fails to capture agency (or distinctively human agency). Further, it seems that genuine agency can be exhibited by beings that are not capable of intentional action, and it has been argued that agency can and should be explained without reference to causally efficacious mental states and events.