If we take actions to be the actualization of some potential, this seems to suggest that there must be an actual and a potential which are interacting in some way so as to produce an actualized potential, which is the product of action.
The question is about a regress that might be noted: if there really are such actions, shouldn't there also be that which is actual and that which is potential? Doesn't the process of actualization presuppose the existence of things that are actualizing and things that are actualized?
In short, how can we talk about doings without talking about things, independent of said doings, that are doing?
And if this is the case, isn't the self-legislating action that is present in some current Kantian pragmatists such as Brandom unable to sustain itself without eventually admitting an ontological commitment to things?