Reply Obj. 3: The act of distributing the goods of the community, belongs to none but those who exercise authority over those goods; and yet distributive justice is also in the subjects to whom those goods are distributed in so far as they are contented by a just distribution. Moreover distribution of common goods is sometimes made not to the state but to the members of a family, and such distribution can be made by authority of a private individual.
Reply Obj. 4: Movement takes its species from the term whereunto. Hence it belongs to legal justice to direct to the common good those matters which concern private individuals: whereas on the contrary it belongs to particular justice to direct the common good to particular individuals by way of distribution.
Reply Obj. 5: Distributive and commutative justice differ not only in respect of unity and multitude, but also in respect of different kinds of due: because common property is due to an individual in one way, and his personal property in another way. _______________________
SECOND ARTICLE [II-II, Q. 61, Art. 2]
Whether the Mean Is to Be Observed in the Same Way in Distributive As in Commutative Justice?
Objection 1: It would seem that the mean in distributive justice is to be observed in the same way as in commutative justice. For each of these is a kind of particular justice, as stated above (A. 1). Now the mean is taken in the same way in all the parts of temperance or fortitude. Therefore the mean should also be observed in the same way in both distributive and commutative justice.
Obj. 2: Further, the form of a moral virtue consists in observing the mean which is determined in accordance with reason. Since, then, one virtue has one form, it seems that the mean for both should be the same.
Obj. 3: Further, in order to observe the mean in distributive justice we have to consider the various deserts of persons. Now a person's deserts are considered also in commutative justice, for instance, in punishments; thus a man who strikes a prince is punished more than one who strikes a private individual. Therefore the mean is observed in the same way in both kinds of justice.
On the contrary, The Philosopher says (Ethic. v, 3, 4) that the mean in distributive justice is observed according to "geometrical proportion," whereas in commutative justice it follows "arithmetical proportion."
I answer that, As stated above (A. 1), in distributive justice something is given to a private individual, in so far as what belongs to the whole is due to the part, and in a quantity that is proportionate to the importance of the position of that part in respect of the whole. Consequently in distributive justice a person receives all the more of the common goods, according as he holds a more prominent position in the community. This prominence in an aristocratic community is gauged according to virtue, in an oligarchy according to wealth, in a democracy according to liberty, and in various ways according to various forms of community. Hence in distributive justice the mean is observed, not according to equality between thing and thing, but according to proportion between things and persons: in such a way that even as one person surpasses another, so that which is given to one person surpasses that which is allotted to another. Hence the Philosopher says (Ethic. v, 3, 4) that the mean in the latter case follows "geometrical proportion," wherein equality depends not on quantity but on proportion. For example we say that 6 is to 4 as 3 is to 2, because in either case the proportion equals 1½; since the greater number is the sum of the lesser plus its half: whereas the equality of excess is not one of quantity, because 6 exceeds 4 by 2, while 3 exceeds 2 by 1.