Freedom, Experiments of Living, and the Knowledge Problem: A Review of Cass Sunstein’s On Liberalism

Over the last decade, a scholarly and popular discourse on liberalism has emerged.¹ Its drivers include economic inequality, populist and nationalist challenges to globalization, and the rise of China—contesting liberalism as the “end of history.” Yet while many of these works are critical, Cass Sunstein’s On Liberalism: In Defense of Freedom offers a new, positive contribution. A Harvard Law School professor and advocate of behavioral economics, Sunstein seeks to articulate the meaning of liberalism in our cultural moment. “Perhaps more than ever, there is an urgent need for a clear understanding of liberalism … of what it is and what it can be.”²

On Liberalism was preceded by a manifesto in The New York Times in 2023, “Why I Am a Liberal,” and Sunstein draws upon and extends it here. Recognizing that critics of liberalism often reject a caricature, Sunstein offers a substantive account of what liberalism is. His argument is that liberalism must advance human freedom and “experiments of living” by shaping the conditions that enable freedom. He draws on political theory, constitutional law, recent history, and—most distinctively—behavioral economics to formulate this. Acknowledging that On Liberalism is not a work of political philosophy, Sunstein takes a course similarly charted by ordoliberals and left-​liberals, integrating a strong role for state action in advancing freedom.

On Liberalism succeeds in expressing a genealogy of the liberal temperament that is marked by openness and humanity, and it excels in its dialectical method and rhetorical style. Yet Sunstein’s distinction between “liberal” and “liberalism” also serves to obscure the meaning of liberalism. In prizing liberality, Sunstein envisions an overly capacious liberalism that integrates a much larger role for positive liberty than most liberal thinkers would allow. And this vision ultimately fails to drive a discernible political program.

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Sunstein’s method is dialectical, a key strength of the book. He often makes assertions about political ideas, followed by a recognition of alternate perspectives. For instance, at one point he declares that “liberals emphasize the value and importance of constraints on individual choice via both norms and law.”³ But he then concedes that constraints on freedom must be justified, especially when formulated in service of the public interest. Similarly, when discussing the need for a liberal behavioral economics, Sunstein notes the limitations of nudges in light of human freedom: “Suppose … we insist that as free agents worthy of respect, people should be free to choose, even if they do not choose wisely.”⁴

Sunstein’s rhetorical style is also strategic. In articulating relatively anodyne ideas most persons can get behind—freedom, rule of law, pluralism—he demonstrates how liberal ideals reflect common sense. He also compellingly distinguishes between schools of thought like political liberalism and perfectionist liberalism, speaking to those who seek out liberalism for its political theory. Further, Sunstein’s expertise in constitutional law shines in the chapter on rule of law, although he could have tempered its granularity by an appeal to Hayek’s notion of abstract rules of just conduct. This is a similarly evolutionary ideal, though more evidently connected to liberalism.

In providing a genealogy of the term “liberal,” Sunstein reminds us that it originally meant openness and generosity of spirit. For Sunstein, to be liberal is to move beyond self-​interest to the common good. He notes that the notion of liberality preceded the term “liberalism,” where liberalism in its earliest origins owed much to this sense rather than to self-​interest. This genealogy provides the conceptual basis for Sunstein’s “big tent” liberalism, informed by a relational ideal of positive liberty.

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According to Sunstein, liberalism need not be restricted to a market-​oriented classical liberalism or neoliberalism. And the vision of liberalism he expounds speaks more to a liberal temperament than to common perceptions of liberalism as a political program. Luke Savage at Jacobin agrees: “It might be that liberal intellectuals like Sunstein associate their tradition more with a kind of centrist disposition than an actual political project distillable to concrete premises.”⁵

One wonders, then, why this work was titled On Liberalism: In Defense of Freedom, rather than Why I Am a Liberal, per Sunstein’s original manifesto. Because Sunstein’s liberalism is so capacious, it ultimately fails to resemble a concrete program. In particular, in eliminating the utility of a negative liberty/​positive liberty distinction, the freedom Sunstein valorizes reads as positive liberty, transforming the general meaning of freedom. Such a notion of freedom, reflected in Sunstein’s proposal for a liberal behavioral economics, exists in tension with his support for experiments of living and recognition of Hayek’s knowledge problem. Different senses of freedom as typically understood collide here: the positive liberty of liberal behavioral economics, where the state seeks to determine objective goods for citizens, and the foundations of experiments of living and the knowledge problem, which center negative liberty over state action. Michael Woronoff at Commentary echoes this concern: “Sunstein claims to embrace Mill’s ‘experiments in living’ philosophy but dismisses the ‘harm principle.’”⁶

Another weakness of the book lies in what it takes for granted. Sunstein asserts that “Liberals believe in six things: freedom, human rights, pluralism, security, the rule of law, and democracy.”⁷ But democracy and security stand out as contested. In part because his understanding of liberalism is so broad, Sunstein claims that all liberals “believe in deliberative democracy,”⁸ drawing on Lincoln’s association between self-​governance of the self and the polity. Such an assertion takes a harmony between liberalism and democracy for granted. This relationship has been disputed by thinkers like Hayek and Tocqueville on excesses of majoritarian rule that suppress individuality,⁹ as well as by Chantal Mouffe in her proposal for agonistic democracy.¹⁰ Another reviewer, John O. McGinnis, similarly notes at Law & Liberty “an under-​theorized account of liberty’s relation to adjacent concepts such as democracy.”¹¹

On the subject of security, moreover, Sunstein tends to read his support for freedom from want into liberalism. “A consensus underlies several of the rights [Franklin Delano Roosevelt] listed, including the right to education, the right to health care, the right to social security.”¹² No consensus exists on state provision of rights. While Sunstein’s attention to justice is commendable—it is difficult to realize one’s possibilities if lacking resources—a state commitment to freedom from want could not coexist easily with negative liberty, with the latter more widely considered an essential principle of classical liberalism.

In articulating a future-​minded vision of liberalism that integrates security or freedom from want, Sunstein calls for a greater role for the state and for behavioral economics. He draws on Hayek to advance it. In Sunstein’s reading, Hayek notes the necessity of a welfare state and a legal framework that supports the competitive market. Sunstein further takes issue with the liberal valorization of non-​coercion, noting contexts where nudges are crucial to avoid serious error. But this assumes that the state can identify and disclose objective wrongs, in tension with Sunstein’s recognition of the knowledge problem.

For Sunstein, “many liberals are generally receptive to nudges, understood as freedom-​preserving interventions.”¹³ The meaning of freedom here is positive liberty, however, not the negative liberty most would associate with liberalism. Sunstein’s approving appraisal of positive liberty affirms the US Second Bill of Rights as part of the liberal tradition—but most would find this a significant departure from liberalism. And such a tension becomes particularly salient in light of Benjamin Constant’s account of modern liberty as “peaceful enjoyment and private independence,”¹⁴ as well as Isaiah Berlin’s notion of negative liberty as freedom from interference, closely associated with liberalism.

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The book also has a key lacuna in terms of counterarguments. Perhaps due to its cultural prominence, Sunstein only addresses the rightist critique from postliberalism—that liberalism atomizes social bonds and contributes to moral decline—rather than the leftist critique from critical theory. Aligned with Tocqueville’s insight, critical theorists like Domenico Losurdo and Achille Mbembe identify a violence to liberalism: liberal democracies professed ideals of liberty, equality, and right while contradicting them in relations of domination, exemplified by the institution of slavery.¹⁵ Are liberal ideals worth pursuing still? This could have been a productive tension to explore, yet Sunstein focuses largely on liberalism as a concept at the expense of its historical reality. Related initiatives seek to resituate scholarship around the dynamism of capitalism and its liberal milieu, including Columbia University’s Center on Capitalism and Society.

Ultimately, On Liberalism is worthwhile, articulating the value of liberalism in our cultural moment. Particularly compelling are Sunstein’s genealogy of the liberal temperament and his dialectical method and rhetorical style. Sunstein’s sources in political theory, constitutional law, and behavioral economics are also helpfully wide-​ranging, aligning with the work of John Rawls, Hillel Steiner, and Peter Vallentyne on the state’s role in advancing freedom. While Sunstein’s work certainly expresses a humane liberal disposition, in its capaciousness it does not resemble a political program. As such, he fails to realize his original vision: that the idea of experiments of living can ground political practice and drive the highest expression of liberalism.