Isaiah Berlin.

According to John Gray, the writings of Isaiah Berlin amount to the most compelling liberal political philosophy of our time. At the heart of Berlin's thought, he claims, is an idea of enormous subversive force, an idea Gray calls "value-pluralism." This is the idea that ultimate human values are objective but irreducibly diverse, that they are conflicting and often uncombinable, and that sometimes when they come into conflict they are incommensurable, or incomparable by any rational measure.

The implication of this view for political philosophy is that the idea of a perfect society is not only utopian but also incoherent. Political life demands that we make radical choices between rival goods and evils. Reason cannot resolve the problem this poses for, in the end, choices invariably bring not only gains but also losses, some of which may be tragic. What this also means is that those dominant liberal philosophies of our time which claim, or hope, that fundamental liberties or fights or claims of justice are compatible or harmonious are seriously in error, if not entirely deluded. Any serious liberal political philosophy should, therefore, begin not with these Panglossian aspirations, but rather with Berlin's more sober, "agonistic" view.

These are bold claims. If defensible, they make Berlin one of the most important political thinkers of our time, while also telling us to rethink in a fundamental way much of contemporary political philosophy. Any review of John Gray's study must, therefore, offer not only an evaluation of its interpretation of Berlin's thought, but also an assessment of the persuasiveness of the larger philosophical claims that lie at the book's core. This is a trickier task than it appears, for while Gray presents himself as Berlin's interpreter he is also an enthusiast who is as much concerned to defend his own political philosophical views. Isaiah Berlin interpreted by John Gray may tell us more about Gray than about Berlin.

Berlin's master idea, in Gray's view, is the idea of value pluralism. The very idea that Berlin has a master idea has, however, the air of paradox about it. One of Berlin's most famous essays, "The Hedgehog and the Fox" (a study of Leo Tolstoy's view of history), distinguished two types of thinkers: those who, like the fox, knew many things, and those who, like the hedgehog, knew one big thing. In maintaining his value-pluralist attitude, Berlin has taken a stance against what he calls "monism" - the idea says Gray, "that there is a single master-value, together with the related idea that all values are somehow necessarily compatible or harmonious." But denying that there is "one big value" seems to be the one big idea that Berlin knows. Is the fox really a hedgehog?

Understanding who Berlin is may throw a little light on this subject. Born in 1909 in Riga, Latvia (where he grew up speaking Russian and German), he was old enough in 1917 to witness the first Russian Revolution when living with his family in Petrograd. He moved to England in 1921, completing his schooling at St. Paul's and his university education at Oxford - where he has lived since (and where he remains a fellow of All Soul's College). He held the Chichele Chair in Social and Political Theory at Oxford (1957-67) and was president of the British Academy (1974-78). As a scholar in one of Britain's leading universities, he became the preeminent, and easily the most influential, historian of European ideas, writing important studies of thinkers ranging from Machiavelli and Marx to Hegel, Vico, and Herder. He also wrote extensively on Russian political thought.

Yet while securely based in Oxford, Berlin was not restricted in his movements or confined in his interests. During World War II he worked for three years for the British government in New York and Washington. He has had extensive personal contact with European philosophers, artists, musicians, and poets, from French-Russian philosopher Alexandre Kojeve to novelist Boris Pasternak, as well as with prominent American thinkers such as Leo Strauss. As a man of letters he has moved easily and often between different intellectual worlds, across the Atlantic as well as across the English Channel, talking and writing about philosophy, literature, and music.

In his intellectual development, however, he was, by his own account, formed by Anglo-American philosophy and by the thought of Immanuel Kant. (Of such modem continental philosophers as Adorno and Derrida, he confesses, he "could not understand a word.") As a Jew and a Zionist he has felt at home in israel because there he has felt free, and not like he was in a foreign country; yet he remains "totally loyal to Britain, to Oxford, to Liberalism, to Israel, to a number of other institutions" with which he identifies. As a moralist, he has disdained totalitarianism both in its communist and fascist incarnations, and his most famous essay, "Two Concepts of Liberty," makes clear his concern for freedom and its fate in the hands of illiberal interpreters who talked of "positive liberty."

This is the man whose thought John Gray represents to us as the ideas of a value pluralist. Berlin's thought, in this account, is rooted in a rejection of a conception of human nature associated with the Enlightenment. Berlin's view, Gray argues, "is a view of man as inherently unfinished and incomplete, of man as at least partly the author of himself and not subject comprehensively to any natural order. It is also a view of man in which the idea of a common or constant human nature has little place, one in which the capacity of man as a supremely inventive species to fashion for itself a plurality of divergent natures is central."

A consequence of this element of indeterminacy in human nature is a diversity of human ways and, thus, a diversity of natures. Indeed, Gray argues, the propensity to diversity is no accident; it is built into the species, for it is implied in man's nature as a species whose life is characterized by the capacity for choice. A further implication of this diversity is that the idea of a single human history is "as misconceived and incoherent as the idea of a perfect human life," for "just as it is in the nature of language that there are always many languages, so there are always many human histories, never only one." The conception of human nature at work here is entirely historicist, and not at all naturalistic.

Now, if Berlin's account of human nature is right, it would make no sense to talk about basic human interests as if all humans could have certain interests in common. And indeed, it is a crucial thesis in Berlin's position that values are plural. More than this, they are necessarily plural. They are also uncombinable and sometimes incommensurable. For Berlin, then, there will arise within any code of morality conflicts among ultimate values which cannot be resolved either by theoretical or practical reason: Liberty may conflict with equality or fairness. In fact, even within each of these goods there may be conflicts: Different liberties may turn out to embody conflicts of incommensurable values (freedom of information versus privacy, for example); as may different equalities (equal opportunity versus equal welfare). Finally, different cultural forms will generate different moralities and values; and, despite some overlap, they will specify many incommensurable virtues and conceptions of the good.

This argument is important not only because it expresses a different view of human nature (or, rather, of the possibility of human nature) but also because it is the basis of John Gray's critique of a variety of liberalisms, all of which he finds guilty of the error of seeking foundations in universal claims about human nature and human values. That it is Gray who is the writer interpreting Berlin is a point of no small significance. Since the early 1980s, John Gray has produced a remarkable number of works which, in the course of exploring the liberal tradition, have sought the foundations of liberalism. In his 1983 study; Mill on Liberty: A Defence, he uncovered those foundations in a version of indirect utilitarianism, but abandoned this as unsatisfactory. In the works that followed, his thought turned for guidance in turn to Hayek's classical liberalism, James Buchanan's contractarianism, and eventually to Michael Oakeshott's skeptical anti-rationalism.

But each of these answers was abandoned as untenable; and over the course of two much-discussed collections of essays, Liberalisms and Postliberalism, liberalism itself was abandoned as incapable of being given any sound philosophical defense, though it might be embraced as a tradition by those people for whom its institutions were a cultural inheritance. By 1995, however, even this position was rejected by Gray in his book Enlightenment's Wake, which saw in liberalism an inheritance that embodied all the worst philosophical errors of the Enlightenment. At the heart of these errors were the misunderstandings of human nature we find evident in the assumptions of all those modem liberal thinkers who have striven, hopelessly and pointlessly, to set liberal principles on a firm footing. The political consequences are to be seen, if Gray is to be believed, in the social disasters of the age: from neo-fascism to the breakdown of human community in market societies.

In the light of this, it has to be asked whether the Isaiah Berlin of John Gray is the real Isaiah Berlin. This is not an easy question to answer because there is much in Berlin's thought that lends credence to Gray's interpretation, The difficulty increases when one remembers that Berlin is, fundamentally, a historian of ideas rather than a philosopher. While he himself is skeptical about this distinction, it remains true that his ideas come to us seldom as direct reflections upon a philosophical problem and more often as commentary on movements of ideas, or on the significance of a single person's thought. Indeed, one might wonder whether it makes sense at all to talk about Berlin's own "thought."

Rather than try to resolve this problem of interpretation directly, it may be worth asking, first, how convincing is Gray's case, not as interpretation but as philosophy. Can one draw from Berlin's writings the anti-Enlightenment case John Gray wishes to mount? The answer here, I suggest, is an emphatic "no." The fundamental argument that must be challenged is the claim that there is no constant human nature because human beings are necessarily diverse - that there is no universal humanity.

Was Joseph de Maistre right (and as insightful as Gray suggests) when he observed, "he has made the acquaintance of Frenchmen, and Englishmen, Italians and Spaniards, but never of man"? Well, there is clearly a sense in which it is true that humans are "inherently plural and diverse." There are many different kinds of people, who speak different languages and live in different ways. Yet this point is trivially true: Superficially, there is "inherent" diversity as long as it is possible to have varieties of the same type. Nothing is gained by saying that this diversity is "inherent" or "necessary." Both chocolate boxes and dating agencies come in different shapes and sizes - how could it be otherwise? Yet they are in no interesting sense inherently diverse and plural. If they are inherently diverse, everything is.

Yet Berlin (or Gray) may be putting forward a subtler claim, to the effect that diversity exists necessarily at some deeper level. Human beings are beings with substantial differences, and these differences are necessary. There are Frenchmen, or Italians, or Spaniards, because cultural diversity is inherently a feature of the human condition. But this doesn't mean much, and it does not obviate the possibility of a universal human nature. Maistre's remark really makes little sense, since an obvious reply would be to say that one has met Parisians, Burgundians, and Alsatians, but never anywhere Frenchmen. A world without Frenchmen is perfectly imaginable: It existed for most of European history. Equally, a France of Frenchmen is quite possible, even if it may have been unimaginable in the days when Europe comprised more than 300 political communities. If the diversity of France can meaningfully be comprehended in the term Frenchman, there is no reason why the diversity of the world cannot equally be comprehended in the term human.

Gray's (or Berlin's) arguments about the significance of the incommensurability of values are also of doubtful importance. Two valuable options are incommensurable, he argues, when neither is better than the other and there is (or could be) another option which is better than one but not better than the other. For example, Aeschylus and Shakespeare are both great dramatists whose dramatic art is incommensurable: It is wrong to say one is better than the other. But we can still say that Euripides is better than Aeschylus without it following that Euripides is better than Shakespeare. The latter two are incomparable because their work exemplifies different values in drama, though we can compare each with other contemporaries. Or, to take another example, we cannot rank a Gothic cathedral with the Taj Mahal. They are simply incomparable. More importantly, forms of life are incomparable.

The implication of all this for ethics, according to Gray, is that the reality of human existence is of an ultimate diversity of incomparable forms of human flourishing. And this means that no single moral theory will be able to guide our conduct when we are confronted by moral dilemmas which force us to forsake one good for another. There is no metric which would enable us to calculate amounts of goodness to allow us to make tradeoffs. Ultimately, then, we have no reason "to abandon the richness and depth of moral life, with all its undecidable dilemmas, for the empty vistas of moral theory."

Yet while incommensurability is possible, it is not clear that it is of much relevance; for it seems only trivially true to say that some goods are incommensurable. All that seems to be happening is that Gray is pointing out that actions or choices have opportunity costs, and that there is no standard "value" by which all opportunity costs can be measured. Economists have known this since 1870. If a comparative judgment is to be made, a common denominator has to be found; that denominator is itself going to be a product of judgment - whether one is comparing different architectural wonders or choosing between apples and bananas. One can choose one or the other in the latter case going on nutrition, or on sweetness, or on colorfulness, or even on price. Similarly, one can choose a metric for measuring dramatic worth - if we have some reason for wanting to do so. (Of course, there may be disputes about the desiderata, but there is no reason in principle why a standard cannot be articulated and established.)

Now, Gray does concede that, in life, tradeoffs are made. What he argues, however, is that incommensurability means that there is no principle or measure showing the unique or universal rationality of particular tradeoffs. What follows from this truth of pluralism, in his argument, is that liberal institutions have no universal authority. For there are no universal human interests or values protected by liberal institutions. If we choose liberal institutions we are simply making a "radical" choice that has no deeper moral or rational basis. Yet it is hard to believe that Gray, or Berlin, really believes this. After all, is there no way of saying that liberalism is morally superior to National Socialism?

And indeed Gray notes that National Socialism is excluded by Berlin's requirement of "minimal universalism." According to Gray, this is a small concession: Recognizing a "common moral horizon" for the human species may disqualify some ideas of the good life (e.g., Nazi ideas), but it does not ground or privilege liberalism. This raises the question of what, exactly, liberalism is. I would argue that "minimal universalism" is precisely what characterizes liberalism. Whether or not his argument was wholly successful, Robert Nozick's idea of utopia as a framework within which different forms of good may be pursued was essentially a kind of minimal universalism. It points to the basic classical liberal or libertarian understanding that ways of flourishing are diverse, that reconciliation of all ways under a single, harmonious, conflictless whole is unlikely, that political institutions should regulate this conflict and facilitate the toleration of different ways by drawing boundaries permitting coexistence. Berlin's thought, if Gray's account is sound, reiterates this view. But it is not clear in what way it offers us a better version of the classical liberal story.

The one point Gray makes that is of some importance is not so much that liberalism cannot be given any secure foundation but rather that what he calls the "liberal form of life" is not to be privileged. Yet this point tells not so much against the libertarian version of liberalism - which accepts that within a libertarian framework illiberal communities may also be sustained. A liberal society, on this view, is not necessarily a society of liberal communities: It may include Amish and Hutterites; Muslims and Christians; separatists as well as cosmopolitans. What this view tells against is that version of modem liberalism, dominant in the academy, which holds that all of society must be brought under the influence of a dominant liberal standard - a standard of social justice - enforced through the agencies of the state. In the end, the central insight of classical liberalism is that human goals, practices, ways of life, are plural and not capable of being brought under control in a single harmonious whole. There are many reasons why this is so; our desire for economic gain, as well as our longing for social acceptance, are among them. The fact that values are sometimes incomparable is only of small importance.

In this regard, what Berlin's thought offers us is not a fundamentally different - let alone a better - version of liberalism. (Indeed, Berlin never set out to provide one.) At best, it offers a reminder of the virtues of moderation, and a warning against the optimism of fanatics. Not all things are possible in the best of all possible worlds. But once it has accepted that perfection is impossible, political theory can surely tell us more. Not because it can provide a blueprint, but because it can at least offer an artist's rendering that better enables us to see our circumstances. All treatises in political theory are flawed; but not all are without insight. Berlin's thought may have avoided the flaws that accompany any grand construction. But the philosophical payoff, as a consequence, is small.

John Gray's study of Berlin claims, ultimately, that Berlin is a hedgehog who knows one big thing. That thing is value pluralism, at whose core is the idea of incommensurability, which Berlin "deploys...in his argument against the dominant tradition of Western thought." And this thing makes his position "a distinctive and novel one that subverts the received orthodoxies in moral and political philosophy." But in the end, Berlin is a philosophical historian of ideas who has really told us many different and interesting things - about thinkers and artists and movements of ideas. He is a fox. The big idea which Gray finds at the center of his thought is only one idea. It is not particularly big, or distinctive, or subversive, or new. And, if we take to heart Berlin's and Gray's counsels of philosophical moderation and caution, we should probably also wonder whether it is entirely true.

Chandran Kukathas ([e-mail]) is a professor of politics at the Australian Defence Force Academy. He is author of Hayek and Modern Liberalism (Oxford University Press).