On Liberalism

Cass Sunstein shows characteristic vision, arriving with a book at the exact moment when solid contributions to the conversation are needed. On Liberalism is a useful prophylactic for critics of liberalism. Liberalism is on the defense from within the tradition as much as from the outside, so the readers of The Independent Review will find more common ground with Sunstein’s defense than they might expect. Sunstein stakes out some very clear boundaries and then raises a big-tent approach to liberalism inviting an intramural argument rather than philosophical antagonism. The aim of the book is to be inclusive while drawing clear enough boundaries so that liberalism’s pluralism is expansive but not plastic. A reader, especially a classical liberal, might agree with Sunstein’s goals almost completely, but still reject his elaboration of the legal architecture necessary to reach those ends.

Sunstein spends Chapter 1 outlining 85 principles he relies on to determine what it means to be a liberal before making an impassioned plea for liberalism in Chapter 2. His pitch for “Experiments in Living” as a progressive liberal ideal anchors the discussion in Sunstein’s appreciation for John Stuart Mill. Sunstein’s presentation of Mill emphasizes common ground between himself and Mill, but drives a wedge between Mill and Hayek, setting up the core tension in the book that frames the intramural argument in liberalism. Chapter 3, titled “Hayek and Mill,” brings this contrast to the foreground. Sunstein characterizes Hayek as “cold, abstract, and distant” (p. 42) in a way that introduces a rhetorical framing, distorting the tension within liberalism as primarily temperament-based rather than procedural and architectural. On p. 47, Sunstein expresses the distortion that he does not resolve: Hayek was not a strictly negative-rights advocate. Sunstein shows that Hayek believed in certain minimum guarantees from the state and a version of comprehensive social insurance.

Mill, himself, had some tension in his work. The harm principle from On Liberty contrasts sharply with the presentation of justified reasons for government intervention in Book V of Mill’s Principles of Political Economy. These justifications not only provide real constraints on Mill’s harm principle, but also there is a missed opportunity for Sunstein to connect his own behavioral interventions detailed on pages 91 to 93 to Mill’s justifications for intervention. That additional intellectual mapping would provide a clear intellectual legacy from Mill’s views on the role of government to Sunstein’s own views on behavioral interventions. Hayek simply weighed the other side of Mill’s concerns expressed in On Liberty. Clarity on Sunstein’s own weighting of Book V of Principles would resolve this tension better than pointing to Hayek’s book on Mill and Harriet Taylor.

Sunstein turns to the rule of law in Chapter 4, showing a solid commitment to big-tent liberalism on this issue. His seven characteristics of the rule of law include items such as the separation of lawmaking from enforcement and the prohibition of unduly rapid change, both of which share procedural rules with folks on Hayek’s side of the tent. Sunstein’s defense of rules as opposed to discretion (pp. 63–69) would be welcome in any public choice seminar on the benefit of constraining opportunism. It is on p. 53 that we start to see the mechanism by which Sunstein’s reliance on good rules determines the legal framework, which in turn works on society to fulfill the promise of liberty. It is this enumeration of the legal framework that will be developed more in Chapter 7 as his defense of positive rights.

Chapter 5 discusses the problem of free speech in a society that both wants freedom and protection from misinformation. Importantly, free speech is a great example of how various approaches in liberalism really distinguish their understanding of the architecture rather than simply pointing at shared goals. If Sunstein had wanted to show where a natural rights tradition declares a space for speech, this example would be ideal. Jud Campbell (Harvard Law Review, 138 [February 2025]: 921–84) draws a distinction useful here in legal contexts, distinguishing between declaring a right and determining it. A complex issue like free speech can be both a right and remain resistant to simple codification. Deterministic accounts reduce the complexity of the right to get easier enforcement but lose much of their protective power in limiting the description. It is here where the Hayekian tradition has its firmest ground, discovery over planning. That concern about overdetermination isn’t just a limit on government intervention, but a philosophical distinction that requires different architecture.

Where Sunstein departs from the shared understanding of liberalism is in treating government and markets as systematically different. Sunstein acknowledges the implication that setting rules picks winners (p. 61) but does not account for how special interests systematically confer privilege even in the best system. The role of competition is limited to markets, forging the recognition that government monopolies are epistemically limited. Contestability in government is epistemic too. This is a surprising omission because discovery, learning, and open epistemics were part of Sunstein’s defense of liberalism in the first place. A shared commitment to competition as a discovery mechanism must be maintained even when policies such as behavioral interventions might be considered expedient. It is a genuine trade-off between intervention and rules against it, such as Mill’s harm principle. Market-oriented liberals require binding limits on intervention as a direct challenge not only to preserve the tension in Mill’s work but to critique Sunstein’s notion of libertarian paternalism too.

Declaring a space for rights without determining how they are constituted is precisely the analytical tension that Campbell takes on in his article cited above. Sunstein side-steps that complexity when he specifies human rights, particularly by endorsing Roosevelt’s Second Bill of Rights. At this point, he is determining rights rather than simply pointing to the space they occupy. This becomes antagonistic in substantial ways to concepts of pluralism, discovery, and open epistemology that Sunstein finds vital in his defense of liberalism. Roosevelt’s rights: to jobs, of farmers for price supports, a decent home for every family, and protection from the fear that accompanies old age, sickness, accident, and unemployment (pp. 109–10) create a kind of plasticity in big-tent liberalism that makes the central pillar start to give way. Sunstein is right both to point to advances in social protections since 1945 and to the influence his address had in shaping the Universal Declaration of Human Rights, despite its lesser-known status in the United States (p. 104–5). But for any comprehensive treatment of liberalism, Sunstein should acknowledge that a disagreement about architecture is a necessary intramural argument that improves liberalism as a whole. He should not merely dismiss the classical liberal position as cold, abstract, and distant. Both Hayek and Sunstein were drawn to Mill. Perhaps the tension in Mill’s work is doing more than what this book acknowledges.

Even in the less elegantly written final chapter, Sunstein points to goals that every liberal can embrace. His focus is on what systems discover the talent that enables human flourishing. This is real and enduring common ground between Sunstein and readers of The Independent Review. Reading this treatment of liberalism helps to reveal that liberals have larger shared goals but some real differences in mechanisms. Both sides believe in a rights ontology that protects the individual from oppression, but the framing of rights as negative explains much of the agreement Hayek has with Mill. Sunstein’s disagreement with that version of Mill is not simply dismissed by caricaturing Hayek’s temperament. This book leaves Hayek as an unresolved puzzle for Sunstein in a way that many who are sympathetic with Hayek will find disenchanting. Because of the shared emphasis on human flourishing, however, readers of TIR should find the book a serious engagement with liberalism at a time when that engagement is desperately needed. Together, in this big tent, liberals need to find ways to work together to better advocate for liberalism’s future.