Contributive Justice and Volition

Doing one's share can be either voluntary or involuntary, or, equivalently, for its own sake or as a means to another end, e. g. avoiding punishment.  Now, among those who regard the distinction as essential are Plato, Aristotle, and Kant, who attribute personal Justness to the Soul, Character, and Intention, respectively.  On the other hand, Mill is among those for whom Volition is not distinct from Action.  Thus, likewise on Consequentialist grounds, he rejects the segregation of Voluntary and Involuntary on the basis that the former is in the realm of 'Ethics' while the latter is not.  But, regardless, any such segregation is irrelevant in at least one case--Economic Contributive Justice, which consists completely in overt actions, e. g. paying dues, performing a chore, etc.  In such situations, motive might be relevant to some considerations, but not to whether or not one has done one's share.  So, Volition is not an essential factor of Contributive Justice, or, hence, of Justice in general.