After lurking in the background for decades of steady and nearly unnoticed growth, economic inequality has come to demand wide attention. Some politicians, such as Bernie Sanders, have defined their campaigns by addressing this as the age’s foremost challenge. And even those who established their campaigns on different terms have acknowledged the creeping issue and have tapped into it to promote their particular platforms. Similarly, after decades of relative inattention, scholars have become considerably more attentive to economic inequality’s sources and various social implications. Most notably, Thomas Piketty’s Capitalism in the 21st Century (2014) has come to dominate this discussion. Piketty argues that the relative economic equality of the middle twentieth century was more an anomaly than the necessary outcome of more than a century of Western capitalism. In fact, his bold thesis is that without serious intervention, unchecked market economies will necessarily distribute resources even more unequally than during the “Gilded Age.”

In On Inequality, Harry G. Frankfurt acknowledges Piketty’s research and certainly the fact that many regard the aforementioned trends as “deplorable” (p. ix). His type of book, however, is very different from Piketty’s. While Piketty himself does not hesitate to repeatedly condemn economic inequality as “excessive,” “shameful,” “beyond all reasonable limits,” and “terrifying” the French economist does not seek to explain why inequality might be understood as such. Rather, in Frankfurt’s view, such condemnations reflect a kind of “elementary common sense” (p. 81). This is pardonable in Piketty, as he is not a philosopher. But if one is to take seriously the problem of economic inequality in the twenty-first century, then surely this calls for a prominent philosopher to take up the challenge of outlining the moral and political difficulties that economic inequality introduces.

Frankfurt surely has such status. As an emeritus philosopher from Princeton, not only is he highly respected in academic circles, but through a series of brief and accessible books on philosophical topics, he has also established himself as someone capable of speaking to a broad audience. If ever there was anyone to take on this task, then, Frankfurt is perhaps the most obvious choice.

Yet Frankfurt does not provide anything like the condemnation of economic inequality that people like Sanders and Piketty might demand. Rather, he seemingly pushes back against these calls to condemn inequality, arguing that “it is misguided to endorse economic egalitarianism as an authentic moral ideal” (p. xi). This is a thesis that he pursues relentlessly through this relatively slim 89-page monograph.

Frankfurt divides his book and its arguments into two halves. The first, more substantive, half is dedicated to a critique of economic egalitarianism, most centrally as manifested in the writings of Abba Lerner (1903–82). The choice of a relatively obscure, long-deceased, twentieth-century economist as a primary interlocutor represents a peculiar choice for Frankfurt. More obvious choices might have included the philosophers, economists, or political scientists who have been attacking economic inequality steadily over the past decade. Or alternatively, he might have engaged the very rich tradition of canonical philosophers who have criticized economic inequality for more than two millennia. This aside for the moment, it is essential to note that Frankfurt’s arguments take place almost exclusively on the narrow moral terrain of the school of Utilitarianism—the doctrine established in the eighteenth century that identifies morally preferable actions as those promoting the greatest aggregate pleasure/happiness or diminishing the most pain.

Lerner’s straightforward argument for equality derives from the principle of diminishing marginal utility. His thesis is that resources are inefficiently distributed in radically unequal societies, insofar as wealthy members derive very little utility from acquiring greater resources, while relatively poorer ones derive significant utility from the same.

Frankfurt responds that Lerner falsely supposes that utility actually diminishes for everyone at the margins. For him, arguments for diminishing marginal utility are largely anecdotal and unsupported (pp. 21–24). Oftentimes, he argues, the sustained consumption of some items increases with greater accumulation—as might happen, for example, with stamp or fine arts collectors (pp. 31–33). In fact, collectors on the verge of completing a “set” can experience far greater utility toward the end of their pursuit than they do in the earlier stages. This suggests, at least for some, a principle of increasing marginal utility, rather than its opposite. And if this is true, Frankfurt concludes, “an egalitarian distribution of income may fail to maximize aggregate utility” (p. 34).

Another strategy the author employs is to consider egalitarianism in the context of scarce resources (pp. 34–40). He asks his readers to imagine a scenario in which 10 people require five units of food each in order to survive, but only 40 total units are available for distribution. In this case, he notes, a strictly egalitarian distribution of four units each would result in the certain death of all 10 people. That is, not only does egalitarianism fail to maximize aggregate utility; it also ensures the death of all its members. It would be, in his words, “morally grotesque” (p. 35). Further, he adds, it is “a mistake to claim that where some people have less than enough, no one should have more than enough” (p. 37). Imagine, for example, that there are 41 units available rather than 40. Assuming that five units go to eight people each, where does the extra unit go? Surely not to one of the two starving people, according to Frankfurt, since “the extra unit is of no particular use . . . to him” (pp. 37–40). The additional unit, therefore, should be distributed to someone else who already has enough food, since this would presumably boost aggregate utility.

Such arguments, however, seem to adopt a kind of misguided and even cruel variant of utilitarianism. Frankfurt’s denial of resources to terminal cases has striking implications. Consider, for example, that there are a limited number of violinists in the world. Does it make sense, therefore, to deploy any of them to hospices to distract and entertain terminal cancer patients? Surely, by Frankfurt’s logic, their utility has ceased to be relevant. Instead, these violinists should presumably be deployed in concert halls for well people. Even by the standards of utilitarianism, this seems false and not a little perverse. As anyone with experience in these matters can confirm, terminal cancer patients can experience pleasure and especially pain. Assuming this to be the case, it would seem that a more egalitarian distribution of violinists would promote greater aggregate utility. Indeed, the author’s logic would seem to condemn palliative care more generally, since it would divert scarce resources to those fated to die.

There is another difficulty in Frankfurt’s argument specifically within the context of his own utilitarianism. Utilitarianism must acknowledge a certain subjectivity in the experiences of pleasure and pain. That is, different people experience pleasure and pain in different things. Yet Frankfurt wants to deny the legitimacy of pain associated with inequality. Rather, the real and genuine pain for him is associated with the kind of deprivations that accompany absolute poverty (pp. 41–42). This appears to be, in fact, a fundamental premise in this book, with the implication that public policy should focus on addressing poverty rather than inequality.But suggesting that the pain associated with inequality is illegitimate is to suggest the illegitimacy of people’s subjective utility preferences, a move that works to undermine the assumptions of utilitarianism itself. It seems a strange move, that is, to begin an argument effectively with the premise that people’s subjective preferences are the foundation of all moral value and then subsequently to suggest that many of those subjective preferences must be altered to match the subjective preferences of the author. In this regard, although Jean-Jacques Rousseau was no utilitarian, Frankfurt would have been wise to heed the Genevan’s advice to “take men as they are, and the laws as they can be.” This would have at least rendered him a more consistent utilitarian.

This nod to Rousseau also suggests greater problems with Frankfurt’s treatment of inequality that extend beyond an inconsistent use of his own meta-ethics. Beyond Lerner’s narrow utilitarian argument for equality, Frankfurt fails to engage any of the other major arguments for addressing inequality that can be found in the philosophical tradition from Plato forward. It was Plato’s Athenian Stranger in the Laws, for example, who characterized economic inequality as the “greatest of all Plagues,” since inequality is the primary source of factionalization and political instability. Variants of this argument inform Aristotle, Augustine, Machiavelli, Hobbes, Rousseau, John Stuart Mill, and even Adam Smith. Often cited as a proto-champion for the market society that produces radical inequality today, Smith is particularly compelling in outlining the damaging effects of economic inequality in his Wealth of Nations—insofar as it creates parallel moral universes in which the wealthy escape moral judgment and the poor are mercilessly punished for meager vices.

To be fair, despite Frankfurt’s repeated assertions that economic inequality is not morally problematic in itself, he acknowledges that it possesses a kind of “almost irresistible tendency to generate unacceptable inequalities of other kinds,” culminating in its capacity to “undermine the integrity of our commitment to democracy”—a tendency that “must be controlled” (p. x). But such statements in this book are typically fleeting, undefended, and unelaborated. In fact, in the context of his larger argument that inequality is morally unproblematic, they raise more concerns than they assuage. If the inevitable result of economic inequality is the kind of problems he acknowledges, then why dedicate so much space to arguing that inequality is morally unproblematic? Surely, the more pressing questions he might have addressed here would include: a) How does a morally unproblematic state of affairs become so problematic? And b) what can be done about those resulting problems?

What, then, might be the actual purpose of this book? Frankfurt’s purpose seems to be to outline what he regards as a notable analytic distinction between the moral status of inequality itself and that of its effects. Yet if he understands the consequence of inequality to be an “almost irresistible tendency to generate unacceptable inequalities of other kinds,” then it is a distinction without much of a difference. It would be as if one were writing a book on the Ebola virus with the thesis that the virus is unproblematic when detached from its biological host. One can certainly make this claim, but that would fail to grasp both its potency and its reasons for sustaining public interest. Indeed, why would anyone read a book with such a thesis?

Beyond questions concerning Frankfurt’s actual intentions, one should also ask how his audience might read this book. To be sure, there are some who would like to believe that inequality is unproblematic because it either confirms their worldviews or because it conforms to their interest in acquiring greater wealth at the expense of others. Such readers—probably not professional philosophers—would take great comfort in an esteemed philosopher’s assurances that there is nothing inherently wrong in their actions. Indeed, popular reviews of his book confirm this, making much of his claim that inequality is morally irrelevant in itself and that nothing at all is inevitable about its connection to other serious moral and political problems (e.g., Will, Carter).

It might seem unfair to hold Frankfurt accountable for his audience. But this book has been clearly written and marketed to appeal to a broad audience of non-philosophers—the kind of people who may not readily distinguish between something’s inherent moral value and its necessary effects. He should know better than to facilitate the deployment of his arguments by the “excessively affluent” who are “guilty of a kind of economic gluttony” (p. 4) and their enablers. To the extent that such people might use his arguments to confirm the moral irrelevance of their own “natural selfishness and rapacity,” to borrow a phrase from Adam Smith, it is more than fair to hold him accountable.