There is a lively debate taking place in libertarian/classical liberal blogosphere over whether the concept of social justice plays a useful role in political philosophy. See, e.g. here: http://daviddfriedman.blogspot.com/ and here: http://bleedingheartlibertarians.com/2013/05/specificity-and-overspecificity-about-social-justice/#comments. Most of this dialog has centered on the question whether this idea can be given a sufficiently precise definition and whether it is internally coherent. While I believe these issues are certainly worth exploring, I am going to argue that even if it satisfies these tests, the inclusion of the concept of social justice in rights-based political theories constitutes a large step down the road to confusion and error.
Those self-identifying libertarians or (more commonly) classical liberals who incorporate the notion of social justice in their theorizing typically claim, very roughly, that a political theory cannot be plausible if its principles do not expressly protect the least advantaged and most vulnerable members of society. This stance is based on their moral intuitions, and is not supported by formal argument. Thus, the motto of the popular website “Bleeding Heart Libertarians,” whose contributors include some dozen academic philosophers, is “free markets and social justice.” This incorporation of social justice into the very fabric of rights-based theories is a superficially attractive strategy that falls apart under close inspection.
Starting with the obvious, it is possible for a philosophical theory to address the legitimate demands of the needy without explicitly incorporating any social justice constraint. For example, a utilitarian theory will hold that a society’s basic structure is just to the extent that it maximizes aggregate (or in some versions, average) utility. Such a theory, while objectionable on other grounds (e.g. failing to accord sufficient stringency to rights), will (at least arguably) not permit widows and orphans to starve in the streets because of the notion of marginal utility. It is certainly reasonable to assume that the destitute derive greater utility from a given quantity of resources than the well-heeled, and therefore, under this theory, wealth should be redistributed to them.
Nozick’s entitlement theory of justice accomplishes the same feat by virtue of his adaptation of the Lockean Proviso, and the “historical shadow” that it casts over current property holdings. Under this theory, if innocent persons are suffering acute harm under a legal regime that enforces stringent property rights, then the Proviso’s condition that such ownership respect the non-appropriators’ right of self-preservation is being violated. Under these circumstances property may be redistributed to those who are affected. For a fuller discussion, see Chapter 6 of my Nozick’s Libertarian Project: An Elaboration and Defense.
Some rights-based political theories lack any organic mechanism for protecting the vulnerable. For example, Rand and Rothbard defend free market capitalism based on moral views that assign a virtually absolute disvalue to the coercion of innocent persons. They implicitly assume that the economy will produce employment for all willing persons, and those unable to work will be provided for by voluntary donations from a generally wealthy citizenry. Of course, such theories leave open the question of what to do if these empirical assumptions prove incorrect, i.e. what do we do if free markets unexpectedly produce widespread misery?
And, we might reasonably regard it as a serious defect in such theories if the answer is “nothing.” But we need not invoke “social justice” in order to make this objection. Rather, such an outcome offends justice simpliciter. According to Aristotle, justice consists of everyone getting what they deserve, and innocent people do not deserve to starve, at least in a land of plenty.
It is important here to understand the nature of ideal theory. Ideal theories of political justice are motivated by specific ethical presuppositions, and these dictate the principles that are to govern the basic institutions of society. For example, Nozick starts by recognizing the transcendent moral significance of rational agency, then describes the implications this has for the moral permissibility of state coercion. Ideal theories all make empirical assumptions that are generally favorable to them.
The problem with introducing demands for social justice at the level of ideal theory is that it arbitrarily focuses on one particular demand of justice while ignoring important others. If the moral legitimacy of a political theory depends on it explicitly addressing the interests of the most vulnerable, why does it not also hinge on its possible impact on other sub-groups and its ability to vindicate their rights. Such groups might include the talented and entrepreneurial, the not-so-talented, ethnic/racial minorities, property holders, non-conformists of various kinds, religious communities, environmentalists, etc.
Incorporating concerns regarding social justice, but not other conditions of justice, into a rights-based theory renders the entire project highly suspect, absent a persuasive rationale for this move; one that I have not heard from those self-described libertarians/classical liberals who make it. Indeed, any such argument along these lines would constitute an independent theory of justice, the ethical foundations of which would have to be specified and defended, reconciled with other competing values (including rights), whose implications would have to be evaluated, and so on.
Of course, it is necessary to consider how ideal theories will function if we were to actually attempt implementation. And some ideal theories of political justice are rendered implausible because their empirical assumptions have proven to be false, e.g. the final nail was driven into the coffin of Marxism when the Soviet Union collapsed due to its gross inferiority, relative to more free market systems, in meeting the basic material needs of its population. It turns out that, low and behold, people will not actually work as productively for the collective as they will for their own account.
However, the debate regarding the form of political economy that would, if instantiated, most fully satisfy the demands of justice falls squarely in the bailiwick of economists, historians, social psychologists, etc. Philosophers have no special authority here, and therefore should stick to arguing over which version of political morality best fits our intuitions, is the most internally consistent, makes the fewest questionable assumptions, etc. This ideal must treat everyone justly. In his later years F.A. Hayek wrote a book titled The Mirage of Social Justice. He is right.