Daniel B. Klein, “Meanings of Liberty: Aron, Constant, Berlin” (April 2021)

Raymond Aron, Benjamin Constant, and Isaiah Berlin are three thinkers whose work illuminates different aspects of the meaning of the idea of "liberty." This collection of essays and responses engages with the differing characterizations of liberty proffered by these individuals, but also looks for unifying threads running between and among them. Daniel B. Klein kicks things off in his lead essay exploring the ideational dimensions of "liberty" as talked about by Aron, Constant, and Berlin. Responses from Professors Helena Rosenblatt and Daniel J. Mahoney will add texture to Klein's analysis, particularly as the three authors engage one another in "the conversation" section below.

The Debate

Lead Essay:

          Daniel B. Klein, "Meanings of Liberty: Aron, Constant, Berlin"

Responses and Rejoinders:

          Daniel J. Mahoney, "Ennobling Liberal Liberties: True Freedom for Political Animals" [Posted April 9, 2021]

About the Authors

Daniel B. Klein is professor of economics and JIN Chair at the Mercatus Center at George Mason University, where he leads a program in Adam Smith. He is chief editor of Econ Journal Watch and author of Knowledge and Coordination: A Liberal Interpretation.

Helena Rosenblatt is professor of history and French at the CUNY Grad Center, as well as a recent recipient of a prestigious Guggenheim Foundation Fellowship. She teaches in the PhD Programs in History, French, and Politicial Science, and the MA Program in Liberal Studies at the Graduate Center. She is also a faculty member of the M.A. Program in Biography and Memoir.

Daniel J. Mahoney holds the Augustine Chair in Distinguished Scholarship at Assumption University and is a Senior Writer at Law & Liberty. His latest books are The Other Solzhenitsyn: Telling the Truth about a Misunderstood Writer and Thinker (St. Augustine’s Press, 2014) and The Idol of Our Age: How the Religion of Humanity Subverts Christianity (Encounter Books, 2018). He is working on a book called The Statesman as Thinker: Ten Portraits of Greatness, Courage, and Moderation, which is under contract with Encounter Books.

Lead Essay: "Meanings of Liberty: Aron, Constant, Berlin"

Tower of Babel

Liberty polysemy according to Aron, Constant, and Berlin

Raymond Aron

   Benjamin Constant   

   Isaiah Berlin

1. Classical liberal meaning


   “negative” if given added specifications

2. Political participation



3. National sovereignty



4. Capabilities




Benjamin Constant distinguished “ancient liberty” and “modern liberty.” Isaiah Berlin distinguished “positive liberty” and “negative liberty.” It is appropriate to see affinity among Constant’s modern liberty, Berlin’s negative liberty, and a classical liberal meaning of liberty.

Meanings of liberty are multiple. When a word has multiple meanings it is said to be polysemous – “poly” as opposed to “mono,” “sem” (sign, signification) as in semantics. Polysemy may be contrasted with monosemy, the property of having only one meaning.

As much as we would like a word, such as liberty, to be monosemous, and to build a tower straight to heaven, like the Tower of Babel, the most important words are polysemous. We must learn to cope with polysemy. The way to do so is to track the different meanings.

It is challenging to sort out the different meanings. How many are there? Are the meanings really different? Are they different yet interrelated?

When I use the word liberty, I usually mean a classical liberal notion of it, which has to do with others not messing with one’s stuff. But there are other meanings to track.

I participated in an event on Raymond Aron (1905-1983), a great French conservative liberal. For the event we read Aron’s 1961 review essay of Friedrich Hayek’s The Constitution of Liberty, in which Hayek attempts to advance a concept of liberty, describing it in a number of ways, including the absence of coercion. Aron broadly embraces an absence-of-coercion definition. But he raises doubts about how Hayek defines “coercion” and so on.  Others too have found Hayek’s elaboration unsatisfactory.

Later I give a few words to a classical liberal meaning of liberty. The thinker who best serves as fount for such a meaning is Adam Smith. But Constant’s “modern liberty” also gives nice expression to a classical liberal meaning of liberty:

It is the right of everyone to express their opinion, choose a profession and practice it, to dispose of property, and even to abuse it; to come and go without permission, and without having to account for their motives or undertakings. It is everyone's right to associate with other individuals, either to discuss their interests, or to profess the religion which they and their associates prefer, or even simply to occupy their days or hours in a way which is most compatible with their inclinations or whims. (Constant 1819)

Aron enumerates four meanings of liberty. Besides [1] the absence-of coercion definition, there are:

three other ideas frequently linked in our time to the concept of liberty: [2] participation in the political order or, more precisely, the choice of rulers by electoral process; [3] the independence of a population governed by men of its own race or nationality, which rejects foreign masters, [4] and finally, the power of the individual or the collectivity to satisfy its desires or to attain its own ends. (Aron 1961/1994, 74)

Aron’s enumeration invites some remarks:

  1. Participation in the political order is aptly associated with republicanism or democratism, the latter especially when we emphasize direct and extensive participation, notably through voting. This meaning corresponds pretty well to Constant’s ancient liberty. Ancient liberty, Constant said, “consisted in exercising collectively, but directly, several parts of the complete sovereignty; in deliberating, in the public square, over war and peace; in forming alliances with foreign governments; in voting laws, in pronouncing judgments; in examining the accounts, the acts, the stewardship of the magistrates; in calling them to appear in front of the assembled people, in accusing, condemning or absolving them.”
  2. In the third meaning, the independence that Aron speaks of is national sovereignty, and hence not suzerainty or domination by a foreign state or power. This meaning of freedom or liberty looms large in issues of imperial powers and emergent secessionist movements—like the American War for Independence and the American Civil War. The meaning is also somewhat apt for an issue like Brexit.
  3. In the fourth meaning we have notions of enlarged capabilities: Winning the lottery augments your liberty. George Stigler (1978) and other economists have associated expanded capability with liberty. Stigler did so in an unbecoming manner dismissive of any classical liberal notion of liberty. But the more important connection is to Berlin’s positive liberty. Such positive liberty is far looser and vaguer than the two preceding definitions. Notions of capabilities and their expansion vary with each speaker’s viewpoint and even with his every utterance, not only about his own inner desires, potential, and fulfillment but about the innerness of others as well. Berlin told us to beware of positive liberty. He said: “historically more damage has been done by pseudo-positive than pseudo-negative liberty” (1991, 41), and “positive liberty has been distorted more disastrously than negative liberty” (147).

So we have a classical liberal meaning plus those three. Here again is the table of designated meanings of liberty:

Liberty polysemy according to Aron, Constant, and Berlin

Raymond Aron

   Benjamin Constant   

   Isaiah Berlin

1. Classical liberal meaning


   “negative” if given added specifications

2. Political participation



3. National sovereignty



4. Capabilities



Berlin says that his concept of “negative liberty” involves an “always recognizable frontier” not to be interfered with (1969, 127). He describes negative liberty as “liberty from; absence of interference” (1969, 127), but he did not spell out any sort of grammar embedded within the concept. Berlin seems to associate negative liberty with Constant’s modern liberty (163-166). Berlin left some equivocation and confusion around “negative liberty.” For example, in Berlin and Jahanbegloo (1991), Berlin speaks of negative liberty as “the removal or absence of...obstacles” (151, 40), which makes it sound like positive liberty (see 1969, 146). But the overall drift of negative liberty is pretty clear, and, were we to give further specification to negative liberty, it would come more clearly into alignment with a classical liberal notion of liberty. I do believe that something of that sort is what Berlin was thinking.

A Classical Liberal Meaning of Liberty

I think that any classical liberal meaning of liberty or freedom ought to start with the virtue of commutative justice, which Adam Smith (TMS, 269) expressed as the duty to “abstaining from what is another’s.”[1] What is another’s, or one’s own, was expressed in Latin as suum. For a classical liberal meaning of liberty, one’s own or suum is understood in a narrow or grammar-like way. This suum may be summarized as person, property, and promises due. (I like to see persons as property of a special sort, as I think of us as souls, each of which owns its person.)

Suum or one’s own (or one’s “stuff”) is delineated according to the rules of ownership of property and voluntary agreement (consent, contract) that operate among jural equals in the time and place of the society in question. Such rules may be said to be that society’s most basic social grammar. Those rules constitute the individual’s dominion that others are presumptively not to mess with.

Suppose your neighbor forcibly asserts that he is to get 25 percent of your income, or tells you that you are not to employ people for less than a certain wage. We’d consider such a neighbor to be initiating coercions. Classical liberals say it’s coercion when done by government, too. Yes, government is a special sort of player in society. Its initiations of coercion are overt, institutionalized, openly rationalized. They are called intervention or restriction or regulation or taxation, rather than extortion, assault, theft, or trespass. But classical liberals maintain that they are initiations of coercion. Recognizing that helps to sustain a presumption against government coercions.

Whereas commutative justice is the duty of not messing with other people’s stuff, liberty is others not messing with your stuff, particularly the government not messing with your stuff. In affirming this elemental concept of liberty, however, classical liberals do not equate liberty and the good.

The liberty maxim says: By and large, in a choice between two reform options (one of which may be not to reform the status quo at all), the greater-liberty option is more desirable.

Notice the “By and large.” It is a maxim. When sustained within the culture, it expresses a presumption of liberty. But a presumption is defeasible. We maintain a presumption of innocence, but sometimes the defendant’s innocence is not sustained.

The liberty maxim is formulated in terms of reforms. A reform implies a status quo. A status quo implies a society in time and place. From that status quo, the liberty maxim is directional, as opposed to destinational (Munger 2018). A classical liberal meaning of liberty need not be concerned with delineating “the free society” or “the proper role” of government. The contours of liberty may be grammar-like, but classical liberal claims for liberty are not grammar-like. They are loose, vague, and indeterminate, and they are circumstanced.

Classical liberals recognize that sometimes liberty must be sacrificed for the sake of liberty. A policy that reduces liberty directly might augment liberty overall. Areas of contention include immigration, foreign policy, weapons policy, pollution, and financial doings for which the taxpayer is on the hook.[2]

The liberty principle has its holes, gray areas, and exceptions; it does not speak to all important issues of government; and it is not self-justifying. Nonetheless, it remains cogent and gives a conceptual spine to classical liberalism. The liberty maxim – that the more-liberty option is presumptively the more desirable option – gives structure to the formulation of issues and positions on issues. We can argue over how strong the presumption is, and how it must compromise sometimes with another important presumption, namely, that of the status quo. But the liberty maxim remains the spine of classical liberalism.

Standing Up for a Meaning of a Word

To stiffen the spine of classical liberalism, Raymond Aron distinguished four meanings of the word liberty. That spine is stiffened and fortified by recognizing the polysemy of liberty and by seeing how a classical liberal meaning stands in relation to other meanings.

To some extent, meanings of liberty vie against one another. One camp may emphasize its favored meaning, hoping to edge out or shut down a meaning cherished by adversaries. Exponents of a classical liberal notion of liberty should take note: eradicating the spine causes collapse.

Recognizing the various meanings helps us to distinguish them. Then we can focus on one at a time. It is my hope that classical liberals will give more attention to articulating a classical liberal meaning of liberty and will stand up for it.


Aron, Raymond. 1994. In Defense of Political Reason: Essays by Raymond Aron. Edited by Daniel J. Mahoney. Rowman & Littlefield.

Berlin, Isaiah. 1969. Two Concepts of Liberty. In: Four Essays on Liberty. Oxford University Press: 118-172.

Berlin, Isaiah and Ramin Jahanbegloo. 1991. Conversations with Isaiah Berlin. Charles Scribner’s Sons.

Constant, Benjamin. 1819. The Liberty of the Moderns Compared with That of the Ancients. https://oll.libertyfund.org/titles/constant-the-liberty-of-ancients-compared-with-that-of-moderns-1819

Diesel, Jonathon. 2021. Two Superiors, Two Jural Relationships in Adam Smith. Adam Smith Review. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3696171

Hayek, Friedrich A. 1960. The Constitution of Liberty. University of Chicago Press.

Klein, Daniel B. 2021. Commutative, Distributive, and Estimative Justice in Adam Smith. Adam Smith Review. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2930837

Klein, Daniel B. and Michael J. Clark. 2010. Direct and Overall Liberty: Areas and Extent of Disagreement. Reason Papers 32: 41-66. https://www.reasonpapers.com/pdf/32/rp_32_3.pdf

Klein, Daniel B. and Erik Matson. 2020. Mere-liberty in David Hume. In: A Companion to David Hume. Ed. M. Polanco. Guatemala: Universidad Francisco Marroquin: 125-160. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3192142

Munger, Michael C. 2018. Can Libertarianism Be a Governing Philosophy? Law & Liberty (Liberty Fund), March 1. Link.

Smith, Adam. 1976. The Theory of Moral Sentiments. Ed. D.D. Raphael and A.L. Macfie. Oxford: Oxford University Press. https://oll.libertyfund.org/titles/smith-the-theory-of-moral-sentiments-and-on-the-origins-of-languages-stewart-ed

Stigler, George J. 1978. Wealth, and Possibly Liberty. Journal of Legal Studies 7(2): 213-217.

[1] On commutative justice and the role it plays in defining two jural relationships (equal-equal and superior-inferior), see Klein 2021 and Diesel 2021. On the historical dependence of liberty on jural integration, see Klein and Matson (2020).

[2] See Klein and Clark (2010).

Daniel J. Mahoney, Ennobling Liberal Liberties: True Freedom for Political Animals

Liberty, as Daniel B. Klein stresses in his succinct and elegant essay for Liberty Matters, is indeed “polysemous,” fraught with different meanings and equivocal in decisive respects. 

Yet the regime of modern liberty, as I will call it taking my lead from Benjamin Constant, requires the broad protection of the liberal liberties, the ones aptly sketched by Constant in his 1819 essay “The Liberty of the Moderns Compared With the Ancients” (and quoted near the beginning of Dan Klein’s reflection): “It is the right of everyone to express their opinions, choose a profession and practice it, to dispose of property, and even to abuse it; to come and go without permission, and without having to account for their motives or undertakings.” Modern liberty, as Constant defines it, also includes the right to freely associate with others, to discuss one’s interests, to choose one’s religion freely, and even to idle away one’s time according to one’s “inclinations or whims.” Constant does not take his bearings mainly or exclusively from theoretical speculation, from a hypothetical state of nature as articulated by the social contract theory of Thomas Hobbes and John Locke. Constant’s understanding of liberty, he tells us, is the one widely shared by the English, French, and Americans of his time. It is first descriptive, and only secondarily, prescriptive. It is the lived experience of those who inhabit modern liberal societies. 

The “modern liberty” that Constant evokes is more concrete than Isaiah Berlin’s “negative liberty.” It implicitly points toward a vision of a free and decent society appropriate to the conditions of modern life. It is at once an appeal to what is “natural,” to what avoids despotic cruelty and undue interference in the private life of individuals, and “historical,” depending as it does on a clear differentiation between the public liberty appropriate to the circumstances of the ancient city, and the private rights and enjoyments that mark the new, specifically “modern” historical dispensation. But, as we shall see, Constant would never condemn every effort to articulate a positive vision of the free, and good, society, and the “rational mastery” of the self and its passions, as a dangerous turn toward “positive liberty,” as Isaiah Berlin does in his 1957 essay “Two Concepts of Liberty.” Berlin’s account of the two liberties, one “negative” and modern, the other “positive” and prone to coercion and despotism, goes too far in identifying liberty with “the removal or absence of…obstacles.” Constant’s account of the difference between ancient and modern liberty stays reasonably close to the texture of real political regimes and historical alternatives; Berlin’s approach is more abstract, and hardly describes any viable political order. 

Berlin is wary, too wary in my view, of pursuing the traditional questions of political philosophy that invariably address the question of the good life and the good society. I do not believe Constant abandoned those questions, even if he circumscribed them by making them, at least in part, historically contingent. But Berlin seems to confuse the search for truth, and rational self-command, with the quest for a “monistic” denial of pluralism and personal freedom. Berlin leaves us with no middle ground between eternal verities and the “relative validity” of our most “sacred” convictions as he states on the last page of his famous essay. Despite his protests, the Berlinian account of pluralism and the radical heterogeneity of values is hardly distinct from relativism. But a liberal society or political order presupposes a certain shared vision of freedom and human flourishing, one that is presupposed by Constant and no doubt by Berlin himself, a political thinker who admirably despised Communist totalitarianism and who wrote eloquently and movingly about the noble statesmanship of Winston S. Churchill. It depends on the preservation of a moral realm, where distinctions between right and wrong, better and worse, are not judged to be merely subjective. The conclusion is clear: Every articulation of the liberty appropriate for free men and women in the modern world inescapably contains an appeal to both negative and positive liberty, of the good life and the good society that maintains an ample space for personal and economic freedom, intellectual inquiry, religious liberty, and moral self-development. That regime, the way of life, forms a “whole.” Liberty can never simply be freedom from, with no positive articulation of the shared goods inherent in civilized life. 

Still, it is hard to quarrel with Dan Klein’s view that the “classical liberal” meaning of liberty, the “spine of liberty,” as he suggestively calls it, involves “others not messing with one’s stuff.” The distinguished French political philosopher and political sociologist Raymond Aron (1905-1983), mentioned and intelligently discussed by Dan, did indeed argue that “liberty as capacity” was a question that naturally arose in any modern productivist society. Aron was a critic of doctrinaire egalitarianism that he believed “vainly contradicts biological and social nature, and leads not to equality but to tyranny.” He did not believe that liberty should be confused with a frenzied passion for equality, or that an ill-defined quest for “social justice” would serve either the political or economic well-being of a free society. But “formal liberties” require certain material goods to exercise them sufficiently. Without them, disgruntled citizens will use the representative or electoral processes to achieve through politics what they cannot achieve through market competition or individual effort. This end-run around the “general rules” of market arrangements is built into the very structure of representative politics. No liberal utopia can do away with this problem or dynamic. There is a liberal way of addressing this dynamic, but it should not be confused with the project of radically depoliticizing the regime of modern liberty and substituting unchangeable rules for the give-and-take, the rough and tumble, of free political life. Friedrich Hayek seemed to move in the direction of an anti-political liberal utopia in his last great work, his three-volume, Law, Legislation, and Liberty

That was not, in Aron’s judgment, the case with Hayek’s earlier The Constitution of Liberty (1960), a true book of political philosophy in Aron’s estimation. As Dan points out, Aron profoundly admired that 1960 work. He shared Hayek’s concern for maintaining the private sphere of civil society, property rights, the absence of undue coercion and restraint on individuals endowed with free will, and the need to respect the rule of law and the constitutional framework of the free society. But in addition to being a conservative-minded liberal, Aron was also a critic of any conception of liberty that dreamed of fundamentally depoliticizing human and social existence. For Aron, following the emphatically political liberalism of his great predecessors and inspirations Montesquieu and Tocqueville, the protection of private rights, and liberal liberties, could not be severed from the broader goal of the self-government of free persons who in important respects govern themselves. This not only provides a salutary restraint on arbitrary government, with its inevitable efforts at self-aggrandizement, but it allows properly civic virtues to flourish. Human beings, Aron liked to say, are citizens as well as consumers. Their talents and capacities can hardly flourish if life is reduced to a strictly hedonistic calculus. 

This is Aron’s challenge to the liberal definition of freedom: Can liberalism, classical liberalism, defend “the spine” of truth at its heart without succumbing to the utopian temptation to create a world without politics (a dream paradoxically shared by Marx and the Marxist tradition if much more blindly and fanatically). Aron’s most radical criticism of Hayek involves faulting the Austrian economist and social philosopher for dismissing the entire “problem of interior liberty” out of hand. In Aron’s considered judgment, there can be no free society without some “metaphysical” or philosophical confidence in the capacity of human beings and citizens to choose reasonably, prudently, responsibly. Aron rightly remarks that the liberal “ideal of a society in which each would be able to choose his gods or his values cannot flourish before its individuals are educated in the common life.” A free society is inseparable from freedom, responsibility, lawfulness, and self-restraint on the part of individuals and citizens in both the private and public realms. This is an essential element of self-government. In the spirit of classical political philosophy, Aron unhesitatingly affirms that “a society must first exist, before it can be free.” Liberal theoreticians, Aron suggests, tend to take for granted the fundamental and enduring problem of political philosophy—and common life. 

In his final lecture at the Collège de France on April 4, 1978, published in French in 2013 as Liberté et Égalité, Raymond Aron reiterated that he unhesitatingly shared the liberal “ideal of permitting to each person the freedom to choose his path” in life. But Aron refused to confuse this necessary and salutary right with the right of each to choose his own “conception of good and evil.“ That should be a bridge too far for the liberal or conservative, for any decent person committed to the search for the Good Life and the preservation of a free and decent civilized order. Moral nihilism is as much a threat to the liberal order as the urge to collectivize human and political life and, in our age, they tend to reinforce each other.

Constant himself ended his famous 1819 address on the liberty of the ancients and the moderns by reminding his auditors and readers that modern liberty needs public liberty both to check power and to “enlarge the spirit” and “ennoble the hearts” of modern individuals who are perhaps too prone to exercise their “individual independence” in ways unworthy of the human soul. The dialogue between ancient and modern liberty, liberal economics and conservative liberal political philosophy, will endure as long as human beings cherish individual independence, political liberty, material prosperity, and the enlargement of the human spirit at the service of truth and moral self-development. But one thing should be clear: “Negative liberty” is too narrow and abstract of a notion to do justice to the capacious liberties that inform and vivify a truly humane and free political order.


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