Defining actions in contradistinction to mere happenings runs into the problem of specifying the role of the agent and separating what the agent does from what they exploit or suffer. Traditionally these problems have been approached by starting with a simple act, such as an incidental movement, and considering causality, or by seeking to elucidate the connection between the act and the agent‟s intentions or reasons. It is suggested here that a promising approach is to shift attention from „simple‟ movements and start instead by exploring the general character of acquired skills. Balancing the body is one such skill and serves here as an exemplar. Some remarks made by Reid on balance are used in a Peircean framework for perception to suggest that, at least for humans, an action is always the performance of an acquired skill. Also, while action is constitutive of perception, bodily perception is the basis of action, providing in a feeling of ownership direct knowledge of an asymmetric opposition between the agent and the world.