Much of Scanlon’s argument is not necessary.

Scanlon says that there are three roads to libertarian conclusions. The first employs the empirical assertion that libertarian policies lead to the greatest good of the greatest number. But, he says—correctly—this argument gives us no reason to accept libertarian philosophy because it is not based on the value of liberty. A utilitarian could accept libertarian policies for the same reason. The second road uses the claim that human autonomy is the greatest good. The third rests on the Lockean right of non-interference. But, Scanlon argues, neither of these latter paths gets you to libertarian policies.

What I want to argue here is that there is a sense in which much of Scanlon’s argument is not necessary, for the the second and third roads are largely, if not completely, superfluous. When the chips are down and libertarians are faced with the potentially monstrous consequences of overvaluing individual autonomy or rights to non-interference, they almost invariably resort to the first road: they retreat to claiming not fiat libertaria ruat caelum but rather that such situations would never arise in practice, because libertarian policies do produce the greatest good for the greatest number.

Consider Robert Nozick’s Anarchy, State, and Utopia. Interwoven in passages about how only the minimal state can be justified because any state larger than the minimal state must violate people's inviolable rights are passages like:

[S]omething should be said about the actual operation of redistributive programs. It has often been noticed, both by proponents of laissez-faire capitalism and by radicals, that the poor in the United States are not net beneficiaries of the total of government programs and interventions in the economy. Much of government regulation of industry was originated and is geared to protect the position of established firms against competition, and many programs most greatly benefit the middle class . . .

This statement is empirically false. First, we are all—or almost all—net beneficiaries of the total of government programs and interventions. Take away our police and our courts and our other government programs and we would have a country that would look much more like modern Somalia than like the United States, and all (or nearly all) benefit from the fact that that is not the case. The rich benefit, true, but the poor benefit as well. Second, the major government programs—Social Security, Medicare, Medicaid, Unemployment Insurance, the Earned Income Tax Credit, and Temporary Assistance for Needy Families, in order of importance—do, with the exception of TANF, benefit the middle class and the poor, largely by raising those who would otherwise be poor into the middle class, and protecting the middle class from the danger of falling into poverty.

We shouldn’t look to libertarianism to provide the greatest good to the greatest number.

Given the passage’s empirical falsity, the interesting question is why Nozick felt that he had to make it. Weren't his arguments strong enough without it? Wasn't he happy saying that a libertarian society is a just society—even if (or rather though) it grinds the faces of the poor in the dirt and makes their lives nasty, brutish, and short? He was not. Nozick felt that his argument for libertarianism was incomplete without the empirical claim that libertarian society is good for the poor.

In a similar but much stronger fashion, Milton Friedman and Rose Director Friedman's Free to Choose asserts the absolute identity of (political and economic) liberty and prosperity, and of tyranny and misery:

The experience of recent years—slowing growth and declining productivity—raises a doubt whether private ingenuity can continue to overcome the deadening effects of government control if we continue to grant ever more power to government, to authorize a “new class” of civil servants to spend ever larger fractions of our income supposedly on our behalf. Sooner or later—and perhaps sooner than many of us expect—an ever bigger government would destroy both the prosperity that we owe to the free market and the human freedom proclaimed so eloquently in the Declaration of Independence. We have not yet reached the point of no return. We are still free as a people to choose whether we shall continue speeding down the “road to serfdom,” as Friedrich Hayek entitled his profound and influential book, or whether we shall set tighter limits on government and rely more heavily on voluntary cooperation among free individuals to achieve our several objectives. Will our golden age come to an end in a relapse into the tyranny and misery that has always been, and remains today, the state of most of mankind? Or shall we have the wisdom, the foresight, and the courage to change our course, to learn from experience, and to benefit from a “rebirth of freedom”?

Economic freedom is, Milton Friedman and Rose Director Friedman believed to their very marrow, a necessary precondition for political freedom in the long-run, and economic freedom and political freedom are each necessary preconditions for prosperity.

They were so convinced of this that they concluded every country with a larger and more interventionist government than the United States—that is further advanced on Hayek's “road to serfdom”—must be, or be on the point of becoming, a socialist hellhole. Consider their view of Sweden suffering by 1980 from:

increasing difficulties. . . . Dissatisfaction has mounted. . . . [Although] Sweden has done far better than Britain . . . it too has recently been experiencing the same difficulties . . . high inflation and high unemployment; opposition to high taxes, leading to the emigration of one of its most talented people; dissatisfaction with social programs. . . . [V]oters have expressed their views at the ballot box . . .

The last thirty years have offered a conclusive empirical test. Sweden has not markedly pruned its social democracy back—and it is doing fine. Indeed, much of the edge that many observers in the 1980s and 1990s saw in the entrepreneurial United States over the more statist economies of Western Europe has turned out to be transitory, if it was not imaginary to begin with. And the costs of 1990s libertarian deregulation of the financial industry have turned out to be extraordinarily high.

Looking around the world and back at history, non-libertarianism—whether you want to call it the New Deal, social democracy, the post-World War II North Atlantic settlement, or the mixed economy—still seems to be our best guess at the institutional arrangements that will lead to the greatest good of the greatest number.