Hume's analysis of human agency

Hume does not fully appreciate the significance his account of human agency has for his search for an experiential origin of the concept of causal power. Hume argues that a metaphysical consideration of human agency cannot afford the concept of causal power. This argument, while successful, only partially addresses the present issue. Hume traces the concept of causal power to the "determination of the mind," or the experience of what it is like to be subject to the influence of custom. What Hume takes to be significant about this experience is that it is characterized by inevitability and efficacy. But the experience of voluntary action, as Hume himself acknowledges, has an equally relevant phenomenal character, namely, the feeling of efficacy or of bringing about change. This means that the phenomenal character of voluntary action satisfies the same criterion that leads Hume to the "determination of the mind": both experiences are paradigmatic of causal power. Of the arguments Hume might bring against the relevance of the phenomenal character of voluntary action, the argument with the greatest potential stems from his account of projection. Hume argues that the phenomenal character of interactions among external objects can be explained away as a projective illusion, that is, as being no more than a projection of the "determination of the mind" onto external objects. If projection is responsible for the ordinary sense we have that objects bring about certain effects in the world, then projection may also be responsible for the ordinary sense that we ourselves effectively bring about change. This argument, however, is not successful. If the phenomenal character of voluntary action is to be a projection of the "determination of the mind," then the former must be fully reducible to the latter. But the experience of voluntary action is essentially active, making it phenomenologically irreducible to the essentially passive experience of custom. Therefore the experience of voluntary action creates an unresolved problem for Hume's claim that the experience of custom is the relevant origin of the concept of causal power.