Rawls was not an egalitarian like Cohen. Equality of distribution for him is merely a tool of thinking; the initial stage (prior to any negotiation) in the original position (not in the actual world). Rawls does not value equality as an independent end, other than as a self-evident way to distribute goods at that point; even Hoppe concedes as much in the Introduction to Rothbard's Ethics of Liberty: Rawls writes that "the first principle of justice requiring an equal distribution (of all resources)... is... obvious"; Hoppe comments: "True; for if it is assumed that 'moral parties' are not human actors but disembodied entities, the notion of private property must indeed appear strange." (EoL, xv)
Cohen's innovation consists in arguing that "in a society of wholehearted commitment to the [difference] principle, there cannot be so stark a contrast between public and private choice. Instead, citizens want their own economic behavior to satisfy the principle, and they help to sustain a moral climate in which others want the same." (RJaE, 70) Thus, his egalitarian ethos completes and consummates the difference principle as personal morality that was at first conceived by Rawls as an instrument of government policy.
Cohen presents some quotes from A Theory of Justice (74ff) to suggest that Rawls might have viewed his approach with some sympathy, but it is certain that Rawls made no explicit allusion to any such thing in the book. The switch from the discussion of what kind of society is best to personal morality is fully Cohen's own baby.
His aim in his moral preaching by his own admission is to "induce agents to accept very high levels of taxation." (70n) Let's trace his argument.
Cohen considers the "threat" of the "rich" to work less hard under higher taxes and shrink the total pie to such an extent that even with redistribution the "poor" will be worse off than under lower taxes to be the same sort of threat that a kidnapper issues to the parents of a kidnapped child. "If the rich could be regarded as external things like machines, of bits of nature," our author goes on, "it would then be irrational for the poor not to accept their proposal" to set up the incentives for them that "work." "But the poor know that the rich are persons, and they may regard them as fellow members of a community who can be asked, face to face, for justification." (65) In short, Cohen proposes that the introduction of incentives for the more talented, such that in seeking their own profit, they also benefit the worst-off, that is, the difference principle, does not follow necessarily from Rawls' reasoning. For if justice demands that the worst-off be taken care of, then the better-off should do their duty to them even without any incentives at all.
But does not Cohen's own ideology treat the rich as machines to be used for the interests of the worse-off? The rich have no rights to spend the money they honestly acquired; they have highly demanding duties to the poor which they must robotically discharge. The symmetry of capitalism is replaced with a one-sided exploitation by the poor of the rich.
The problem, once again, is that people act for ends. Presumably, by working they intend to earn money which they then plan to spend on their own pleasures. In submitting to the disutility of labor, people aim to profit. They are not robots who perform "duties" automatically and without feeling. It is not the case that the better-off are working essentially to increase the welfare of the worse-off and as a disturbing and unwelcome accident of this improve their own welfare even more. On the contrary, they work essentially for themselves, and as an accident, make even the worse-off happier. If the first were true, then I agree that one could question why they should have "incentives" when it is their "moral duty" to assist the worse-off. The talented would be bound to the worse-off in a sort of indentured servitude. But if second which seems true to me, then it is merely proof that capitalism enriches the entire society. The natural aristocracy is dragooned into service to society as a whole through the cleverness of the economists.
Hence in order to keep working hard even at high taxes, the "rich" must benefit from doing just that. Logically, their goal can be one of the following two things.
1. They desire to improve the lives of the worst off, which means that they love them and acutely feel their pain. This sort of mighty charity is implausible, as only God is capable of personally loving each of the billions of humans.
2. They desire universal equality and themselves to be equal to everyone else. This is to be sure a strange goal. It seems preposterous and inhuman. Probably almost no one who ever lived actually had it. Cohen has not as of Chapter 1 proven the people ought to desire this, and that those who fail to desire this are awful sinners who must immediately reform.
Cohen can reply that he merely takes the difference principle to its logical conclusion. But a difficulty appears posthaste. Cohen's argument can be put thusly. Let there be a society D1 marked by equality of distribution. Rawls appears and suggests that everyone in this society can become better off by allowing the talented some incentives to perform, but at the expense of equality. The talented thereby work harder and produce more wealth, prospering themselves yet also creating value for the less fortunate. Name this society D2. Cohen retorts that a still better society D3 is possible: one in which the talented work just as hard, but the fruits of their labor are nevertheless distributed equally. Amazing! D1 has been transformed into far richer superior D3 by a philosophical argument!
Cohen seems to have invented a perpetual motion machine that improves economies all by itself. An even more wonderful D5 is sure to follow.
Of course, Cohen has simply commanded certain people to work harder or brainwashed them that doing so is their alleged moral duty; if they obey, then total product will have obviously increased, and each person's equal share will be greater, as well. But how many times will he be able to crack his whip? Surely, there is a limit to how "hard" any individual must work to satisfy a deity even as demanding as Cohen?
The ultimate problem here is that such commands and brainwashing have nothing to do with the egalitarian ethos, as understood by Cohen. Desire for equality and devotion to work are not connected in any way. That one is an egalitarian does not entail that he must work more or less hard. The talented do not owe a definite and large sum of money to the poor, such that to repay the debt they have to exhaust themselves in hard labor for life.
The emergence of D3 from D1 ex nihilo is a cheap trick unworthy of a philosopher.