Let me re-post an argument.
David Friedman’s bureaucrat-god is simply a substitute for Friedman himself who, graced perhaps with some disinterested benevolence, imagines himself qualified freely to scatter largess to the populace. Even if Friedman was a wonderful person who wanted to help all the deserving poor, then this would be his own personal value judgment.
Real people help the poor out of love for them; the givers, too, benefit, as the receivers’ happiness overflows into them, as they themselves feel to an extent the receivers’ joy at the gift given. Regarding this goal, every dollar given helps. Charity is a consumer good for the givers, so whatever is given is the “right” amount.
Friedman would be out of line to seek to substitute his preferences, however lofty, for those of other people.
Consider the following three possibilities. First, the government forces a transfer from the better-off Smith to some poor slob Jones. Straightforwardly, Smith loses, and Jones gains. No conclusion about the “overall welfare” can be drawn in this scenario.
Second, Smith helps Jones out of a sense of moral duty. There is a sense in which society as a whole may be better off. Smith thinks he sacrifices “less” of his own good than Jones benefits. It is still a forced transfer, as moral duties restrict freedom and impose requirements, but at least Smith “forces himself.” In addition, Smith may be wrong. Here, then, it is at least plausible that total welfare increases, though not certain.
Third, Smith helps Jones because he feels love of friendship for him. It may be familiar love, marital love, brotherly love; it’s not that important. In this case, the receiver Jones benefits, but so does the giver Smith who “feel Jones’ feelings” with him, rejoicing at his joy.
St. Thomas identifies the effect of love as union (spiritual, obviously, but also bodily in the case of sex), mutual indwelling, ecstasy, and zeal among the lovers in and for each other. The wills of Smith and Jones unite or intertwine. If they are connected with the divine, as well, then we obtain the Christian metaphor of the vine and branches.
The Catholic Encyclopedia describes it as follows: “In that communion there is no loss of individuality, yet such an interdependence that the saints are ‘members one of another,’ not only sharing the same blessings and exchanging good offices and prayers, but also partaking of the same corporate life, for ‘the whole body… by what every joint supplieth… maketh increase… unto the edifying of itself in charity.'”
It is only in this third case that total utility definitely increases as a result of a work of mercy.