The social philosopher Michael Walzer has argued that justice itself cannot be based on a simple one-size-fits-all understanding of what just behavior entails. In his book Spheres of Justice, he argues that different kinds of 'goods' (i.e., things people value) have different social meanings and that the proper rule for just distribution of those goods depends on their meanings. Thus, for example, simple economic commodities are distributed by the rule of the market: Each will receive as income what others are willing to offer to get the things he originally owned. But other social goods must be distributed by other rules. Honors should go to those who deserve them, not those who can pay the most for them. Even though the criteria for deserving a Nobel prize in physics are quite different from those for a gold medal in the hundred-meter dash at the Olympics, it would be unjust to buy (or sell) either honor. Essential goods and services, whether that is the help of the police when one has been robbed or sufficient food to feed one's family when one is unemployed, should be distributed in accord with needs. Offices (jobs that have a political import of some kind) are distributed in accord with the criteria that define them. Similarly, citizenship, education, love, and political power are all distributed by different principles.
Walzer's point is that different kinds of goods ought to be distributed under different rules because their diverse meanings should be respected. Thus one of Walzer's fundamental critiques is directed at libertarians and a number of other market proponents who see no problem in extending the logic of the market - one person makes an offer and the other decides whether or not to accept it - into other areas of life where this market mentality undermines widely accepted views of justice. From this perspective, whether or not economic self-interest in the sphere of money and commodities is morally attractive, it is morally quite offensive as it pushes into other spheres of life.
The Moral Ecology of Markets, Daniel K. Finn