The question of how to effectively employ the powers of the state to bring about a Fair Society is the "bread and butter" issue of all social and political philosophers. There are two underlying distinctions that cloud our understanding of the distribution of benefits and costs among humans: natural distribution and social distribution.
First of all, Nature provides all of us with a set of natural advantages and natural disadvantages that affect how we we fare in a Darwinian world. As John Rawls noted, these advantages and disadvantages are distributed based on a "natural lottery," which is partly genetic (lucky draw of genes) and partly social (lucky draw of parents and society). Given that nature "distributes" these advantages and disadvantages randomly, it's hard to argue that any of us "deserve" our current economic status. In other words, Mother Nature is not fair, because she blindly stacks the cards either in our favor, against us, or both. Therefore, social and political philosophers on the left, like Karl Marx and John Rawls, argue that the purpose of government is to use the coercive power of government to redistribute benefits and costs. Since merit (adaptive attributes such as high IQ and good looks) and need (maladaptive attributes such as low IQ and ugliness) are distributed unfairly, leftists argue that the purpose of government is to redistribute the fruits of the natural lottery. Call it: economic security.
So how do we go about this social redistribution process? Well, Aristotle identified four material principles of fairness: merit (the best get the most), need (the neediest get the most), equality (everyone gets the same), and utility (the distribution that affords the "greatest happiness for the greatest number"). Aristotle, a natural law theorist defended meritocracy, where all social structures are designed to make sure that the advantaged get the most and the least advantaged get the least: "the best get the most and the worst get the least." Any society that varies from this standard is unfair. He argued that the needs of the least advantaged are to be met by the virtuous acts (beneficence) of the meritocrats. But if neither merit nor need is deserved, neither is virtue." Not only did my parents pass on bad genes, they also failed to teach me virtue!" Therefore, how can I be held morally responsible for robbing that Quicky Mart last week? After all, I needed the money and the owner of the that store that I robbed inherited that successful business, along with a high IQ and good looks. So he didn't "deserve" that money, either.
Rawlians and Marxists solve this merit v. need struggle by using the coercive power of government to take a certain percentage of the store owners income and giving it to me, so I won't have to steal it in order to meet my needs. Marx (and B.F. Skinner) dismissed private property all together and argued that all goods are social goods, and therefore ought to be redistributed equally by a panel of government experts. Rawls argued that the most advantaged ought to be forced to contribute to a "basic safety net" or provide a social minimum to protect the least advantaged. Rawls, therefore, allows the most advantaged to prosper, but only as long as the social distance between the rich and the poor either diminishes or does not increase. The rich cannot get richer, if the poor get poorer as a result of a natural distribution.
So the common strategy employed by left-wing Marxists and Rawlsians is to use the power of government to eliminate or lessen the consequences of natural inequality. Now what do right-wing libertarians say about all this? Well, they present a long list of counter-arguments. Next time, I'll sketch in a few of them. Stay tuned.