Fundamental shifts in values are among the slowest of all social processes. Fashions change by the year, laws by the decade, and political systems by the century. In contrast, it took millennia for attitudes toward slavery to shift from almost universal acceptance to almost universal abhorrence. In almost all cases, arguments for a new value or against an old one long precede the deeply held moral intuitions that signal a genuine shift in values. Arguments for the equal rights of women date back to the seventeenth century in Europe; it took until the twentieth centuries for at least some polities to extend suffrage to women (among European countries, Lichtenstein held out until 1984); and it is debatable how firmly anchored the moral intuition of women's equality is even in countries that have allowed them to vote for a century or more, as in Afghanistan, where women were granted the right to vote in 1919. Advocates for economic equality have been arguing their case since the eighteenth century, but they have yet to cross even the threshold of legislation, much less that of a moral intuition that no longer needs to be debated. The value of solidarity has been even slower in establishing itself.

So, the breathtaking speed with which diversity has entrenched itself not only in argument and legislation but also as a viscerally felt moral intuition, a value that provokes outrage when violated, is nothing short of astonishing. This Google Ngram is a crude but suggestive indicator of when the meteoric rise of diversity as a social, political, and moral value began, at least in English. Starting circa 1970, the frequency with which the word appears in the Google Books corpus rises, but a closer look at the book titles from which the data base draws its sample suggests that the majority of these are about biodiversity, with a smaller number devoted to cultural diversity. After 1990, the rise is steeper, with a few small dips after 2010, but still at roughly five times the 1960 frequency. The titles of the books in the Google database shift decisively toward titles like Encyclopedia of Diversity in Education and Managing Cultural Diversity, although biodiversity is still prominently represented. Both the shape of the curve and the dates of the inflection points tally, with about a five-year lag time, with results for diversité in French and Diversität in German – albeit with sharper dips around 2010. These results suggest at least a rough periodization and also the direction of influence from the U.S. to Europe, as in the German case, in which "diversity" begins as an English import and then is naturalized as "Diversität". The corpus of French books shows "diversité" approaching and even surpassing the far more entrenched republican value of "égalité"; the sister value of "fraternité" never comes close to either in frequency of usage. (For those curious about the third value in the triumvirate: "liberté" surpasses both égalité" and "diversité" by a wide margin.

These results can be at best suggestive. The Google corpus of books for each of these languages, although large, is unlikely to be a random sample. And even if it were, the Ngrams show only frequency of usage, with no indication of context, much less valorization – positive, negative, or neutral. But combined with other sources, from scholarly articles to legal opinions to business mission statements, they point to a remarkable episode in the history of political and social values: the emergence, spread, and acceptance of a new value, all in a matter of decades, not centuries. The contrast with the slow, halting advance of the much older value of equality is particularly striking. At first glance, the political values of equality and diversity may seem to overlap, even to coincide, at least in their goals of widening the circle of social inclusion. One might ask, isn't diversity simply a new, improved version of equality, one better suited to multicultural polities? But on closer inspection, divergences appear. Equality has staked its claims to what is common to all human beings, whereas diversity insists on what distinguishes one individual from another. Equality is a universalist value; diversity, an identitarian one. They can and often do tug in different directions when applied to concrete cases. Why, then, did diversity overtake and surpass equality as a value, and with such astonishing speed?

The aim of this brief attempt to answer that question is twofold: first, to explain what made the meteoric rise of the new political and moral value of diversity possible; and second, to use the case of diversity as a way of rethinking the nature of value – more specifically, whether the various domains of value – aesthetic, political, economic, epistemic – are really as independent and separate as philosophy makes them out to be. I'll argue that this most recent incarnation of the value of diversity in the political realm is drawing its authority from earlier versions of diversity – first, as an aesthetic value, and later, as an economic one. Like a budding plant with deep, hidden roots, the current self-evidence of diversity taps into a long history of how and why diversity has been valued. The kind of diversity has shifted over time, as have the justifications for valorizing it, but each new version of diversity has piggy-backed on its predecessors. This prehistory of our current political value of diversity goes some way toward explaining how it went from being a trendy neologism in the 1990s to a self-evident good today.

I. Diversity as Beauty

It was not an accident that biodiversity and cultural diversity are often twinned in current political debates. Since ancient times, the overflowing fecundity of nature, the sheer exuberant excess of its colors and forms, had served as the premiere example of diversity as beauty. For the Roman encyclopedist Pliny the Elder, there was something wondrous about the gorgeous but apparently pointless proliferation of flowers, and in his compendious Historia naturalis (77-79 CE), he traced the beginnings of painting to artists' attempts to mimic and surpass their infinite variety. Pliny thought flowers showed nature at play: 'Nature [...] is in her most sportive mood, playful in her great joy at her varied fertility'.¹ Almost two thousand years later, when German philosopher Immanuel Kant cast about for an example of beauty that commands admiration just because it serves no purpose and can be subsumed under no concept, what first came to mind were not paintings and sculptures but flowers.² Flowers were more than nature's own artworks; they also evoked the purest, freest aesthetic judgment.

The enormous commercial and later imperialist European expansion during the sixteenth and seventeenth centuries not only enriched gardens with imported exotica like passion flowers from the Americas and tulips from the Levant, they immensely expanded the variety of both natural and artificial objects available in bustling port cities like Lisbon or Amsterdam. The aesthetic of diversity also expanded to embrace these novelties, from Chinese porcelain to polished nautilus shells from the Indo-Pacific. Still life paintings from this period, the seventeenth-century analogue of today's glossy advertising photos, juxtaposed these expensive rarities in a visual allegory of luxury, variety, and virtuosity in the works of both art and nature. Depictions of lands newly opened to trade and subjected to conquest featured a similar aesthetic of diversity, blurring the boundaries between art and nature and between cultures and commodities. The early modern European aesthetic of diversity probably achieved its most memorable expression in the deliberate miscellany of the Wunderkammer, zany ancestor of the modern museum, in which two-headed snakes were displayed cheek-and-jowl with delicate frigates carved from ivory, insects preserved in amber with stuffed crocodiles, and unicorn horns with exquisite clockwork.

In all of its mutations, from flowering meadow to Wunderkammer, the aesthetic of diversity never shed its associations with excess above and beyond any conceivable utility. The aesthetic of diversity was intrinsically wastrel, flaunting its prodigal extravagance and disdaining all frugality. So, it comes as something of a shock to find the value of diversity keeping the company of economic efficiency in the late eighteenth and nineteenth centuries.

II. Diversity as Efficiency

A mid-eighteenth-century pin factory in Normandy stages one of the most famous scenes in the history of economics. The article on pin manufacture ("Épingle") in the great Encyclopédie of Denis Diderot and Jean d'Alembert opens with an evocation of the universe in a grain of sand – or at least of complexity in a simple pin: "The pin is of all mechanical works the tiniest, the most common, the least valuable, and yet one of those that requires perhaps the most combinations ... for a pin undergoes eighteen operations before it enters commerce."³ From the arrival of coils of metal from Hamburg or Sweden to the sticking of the finished pins, a dozen at a time, into paper slips, the article lays out the manufacture of pins circa 1750 step by step. Staffed by experienced workers, the factory could be mind-spinningly efficient, producing up to 48,000 pins per day. Influenced by this article, Adam Smith began The Wealth of Nations (1776) with the pin factory as a shining example of how the division of labor promoted efficiency and technological innovation.⁴

The division of labor went on to have a meteoric nineteenth-century career, well beyond economic theory and industrial applications. It was a key inspiration for Charles Babbage's design of the first computer, as well as for Émile Durkheim's theory of the organic solidarity of advanced societies. The principle could be as readily applied to the factory assembly line as to the steps in a computer program – or to the differentiation of functions in a bustling city like Paris, in which cobblers make shoes, tailors make clothes, masons lay bricks, apothecaries make drugs, bakers bake bread, and so on. By the mid-nineteenth century, the division of labor became a keystone of political economy and was almost synonymous with efficiency.

But for our purposes, the most consequential application of the principle of the division of labor was to the life sciences, first to physiology and then to evolutionary theory. Specialization by task or function might produce diversity – all those different jobs that kept Paris running – but it did not produce beauty. It was the biologists who discovered how to connect the old diversity of beauty in nature with the new diversity of efficiency in human society – and indeed to use the one to explain the other.

The French physiologist and comparative zoologist Henri Milne-Edwards had been the beneficiary of the vast natural history collections amassed during the eighteenth and early nineteenth centuries, as well as of the efforts made to bring some classificatory order into what had seemed to be the infinite variety of living organisms. The first edition of the Swedish naturalist Carolus von Linnaeus's wishfully named Systema naturae(1735) – no one at the that time could be sure that there was a system of nature – ran to only 12 pages; by the time the multi-volume twelfth edition (1766-68) appeared, all the new species discovered in the meantime had swelled the total to 2,300 pages. As new observations and specimens streamed into Uppsala from correspondents and travelers all over the world, Linnaeus scrambled to keep his classification scheme from buckling under the weight of what we would call biodiversity, and Linnaeus called God's masterpiece.⁵ Milne-Edwards was similarly overwhelmed by the "diversity ... which seems to be the primary condition imposed on nature in the formation of animals." But beneath the prodigal variety of nature's forms, Milne-Edwards detected a fundamental organizational principle, the division of labor:

One sees that in the creations of nature, as in the industry of man, it is above all by the division of labor that perfection is obtained.

The body of humans and other complex organisms was, Milne-Edwards claimed, exactly analogous to a modern factory: every organ was specialized to a specific function, just like the workers in the pin factory. Stomachs did not think, and brains did not digest. Milne-Edwards drew the paradoxical conclusion that it was precisely nature's "tendency toward economy" that produced the wastrel diversity of forms. The 7,000 then-known species of birds seemed to exhibit the most extravagant diversity of form and color; yet nature had achieved this result at "little cost," by working and reworking "the same materials" to different, ever more specialized ends.⁶

In On the Origin of Species (1859), Charles Darwin made Milne-Edward's insight his own and used it as the foundation of his theory of speciation, once again invoking the division of labor:

The advantage of the diversification in the inhabitants of the same region is, in fact, the same as that of the physiological division of labour in the organs of the same individual body – a subject so well elucidated by Milne Edwards ... So, in the general economy of any land, the more widely and perfectly animals and plants are diversified for different habits of life, so will a greater number of individuals be capable of there supporting themselves.⁷

Nature was no longer a Wunderkammer but an economy run on the most efficient principles to yield maximum productivity, no longer a playground for nature's fertile fancy but an arena of ferocious competition for scarce resources. Yet in Darwin's account of speciation, diversity-as beauty and diversity-as-efficiency merged: Pliny's wondrous cornucopia of natural forms merged with Adam Smith's pin factory. The result was our current understanding and appreciation of biodiversity. Both the aesthetic and economic values of diversity still resonate as undertones in the most recent incarnation of diversity as a value, this time in the political realm.

III. Diversity as Justice

There is widespread agreement among scholars that the rise and rise of diversity as a political value began in the United States in the 1960s, with campaigns for equality, first and foremost, the Civil Rights movement to secure equal rights for black Americans. In campaigns closely modeled on the Civil Rights movement, activist groups representing first women and later gays and lesbians organized to tear down legal barriers to equality, especially in the job and housing market. All of these movements marched under the banner of equality for all citizens, regardless of race, gender, or sexuality, and all fortified their claims to equal treatment in a democracy with demographic arguments: how could a significant portion of the population (estimates as to percentages comprised by each group varied from 10% to 50%) be denied equal rights? Accordingly, legislation and government programs that attempted to redress these wrongs, such as Equal Employment Opportunity and Affirmative Action, set goals for each of these groups in the workplace, the military, the civil service, and the universities that matched their statistical proportion of the population. For example, if black Americans represented 12% of the population, then they should ideally constitute 12% of public sector employees, university students, army officers, business executives, etc. In the 1970s and 1980s, other groups, such as Native Americans, were added to the list of those served by these programs.

But even if the principle of equality for these groups gained gradual acceptance, the programs designed to enforce those principles were politically controversial, especially if they involved quotas or positive discrimination, which became known as "affirmative action." After a number of landmark U.S. Supreme Court decisions struck down Affirmative Action programs as unconstitutional, a new specialty known as "diversity management" replaced Affirmative Action offices in both the public and private sectors. In the U.S., "diversity" had decisively edged out "equality" in policies and mission statements by the 1990s; by 2012, the European Union had also begun to adopt the language of "diversity" in its directives to member states. European countries with strong corporate ties to the U.S., such as Germany, were in the vanguard of adopting both the new language and new measures.⁸

The rise of diversity correlated with the decline of equality, the latter understood as the proportional representation of groups that had been historically the victims of discrimination – mostly ethnic minorities, but also women, who were by most counts the majority of the population. At this point in the story, the spotlight shifts to the university. This is still a history in the making, and I fully expect to find significant variations in different languages and the polities that speak them. However, since the mutation in meaning seems to have occurred earliest in English, and in American English before British English, then spreading to other languages (recall those Google N-Grams for French and German), it's worth taking a closer look at events there that catapulted diversity-as-justice into title-grabbing prominence. But a word of caution: what I am about to present is a preliminary and limited survey of the sources, focused mostly on legal cases relating to universities, and should therefore be taken with a generous shake of salt.

The pivot of this preliminary sketch of a history is the U.S. Supreme Court decision in the case of Bakke v. Regents of the University of California (438 U.S. 285 (1978)) in 1978. Allan Bakke's application to the University of California, Davis medical school had been twice rejected, and he sued the university for violation of his right to equal protection under the law, as guaranteed by the Fourteenth Amendment to the U.S. Constitution, because he believed that the university's affirmative action policies discriminated in favor of black applicants at the expense of white applicants like himself. The majority opinion of the Supreme Court struck down the university's policy of reserving a certain number of places in each medical school class for black students as unconstitutional but upheld the university's right to take race into account as one dimension among many in the evaluation of applicants in the interests of promoting "diversity." Writing for the majority, Justice Lewis Powell cited with approval Harvard University's recently enlarged "concept of diversity to include students from disadvantaged economic, racial and ethnic groups." Powell went on to provide a vivid example:

When the [Harvard] Committee on Admissions reviews the large middle group who are 'admissible' and deemed capable of doing good work in their courses, the race of an applicant may tip the balance in his favor just as geographic origin or a life spent on a farm may tip the balance in other candidates' cases. A farm boy from Idaho can bring something to Harvard College that a Bostonian cannot offer. Similarly, a black student can usually bring something that a white person cannot offer....⁹

Almost overnight, the diversity argument replaced other justifications for positive discrimination in favor of disadvantaged minorities, most notably the argument of undoing the historical effects of slavery and prejudice and of compensating for structural economic and social inequalities.

Astonishingly, the response to the Bakke decision was almost universally positive: the conservative right rejoiced in the fact that racial quotas had been eliminated (and that Allan Bakke had finally been admitted to medical school); the liberal left celebrated the diversity doctrine as the royal road to including minorities not only in elite universities like Harvard but also in the ranks of corporate executives and military officers. As the Wall Street Journal summed up prevailing reactions in its headline on the occasion of the Supreme Court decision, Bakke was a case that "everybody won." Until the current Supreme Court overturned the Bakke decision in 2023¹⁰ (notably in a case filed against Harvard), diversity-as-justice was not only the law of the land; it was almost a moral platitude, as unassailable as motherhood and apple pie.¹¹

I do not wish to exaggerate the influence of a single American court case. Other, arguably more momentous political events elsewhere in the world surely prepared the way for the astonishing success of diversity as a political value. Here I can only give one example, but one which attracted worldwide attention. After the first democratic elections of April 1994 that elected Nelson Mandela to the presidency of South Africa, Archbishop Desmond Tutu declared that South Africans were "the rainbow people of God. We are free – all of us, black and white together!" Tutu's rainbow was an explicitly religious symbol, meant to evoke the rainbow sealing the covenant between God and humanity after the biblical flood.¹² Mandela adapted the phrase to more civic ends and underscored the multiracial associations of the multicolored rainbow in his first presidential inaugural address in May 1994: "We enter into a covenant that we shall build the society in which all South Africans, both black and white, will be able to walk tall, ... a rainbow nation at peace with itself and the world."¹³Suddenly, rainbows became the emblem of diversity everywhere.

The American and South African parts of this story might not have been as unconnected as they seem at first glance. Once again, the missing link seems to have been Harvard. Even before the end of apartheid, some South African universities, notably the University of Cape Town and the University of Witwatersrand, had defended "racial diversity within the university" as fundamental to a multiracial society against the apartheid government. By a circuitous route, these arguments reached the ears of the Harvard Law School professors who drafted the brief that Justice Powell quoted with such approval in the Bakke decision. The chancellors of both South African universities, one of whom was also Chief Justice in that country, had visited Harvard Law School and left a deep impression on some of its faculty, some of whom went on to write influential briefs that framed the question of justice in terms of diversity, rather than equality or reparation.¹⁴ Despite very different histories and politics, there were resonant chords struck between South Africa and the United States, two multiracial nations striving to heal the scars left by slavery, conquest, and segregation, and also two nations that had historically both defined race by skin color. By the end of the first decade of the twenty-first century, diversity had become a self-evident value in many countries, and its universal symbol became the rainbow, South Africa's proud badge of many colors.

In the ramifying applications of the arguments of the Bakke decision in realms as various as optimizing decisions in the workplace to fortifying scientific research against bias, the principle of the division of labor shadowed the value of diversity-as-justice. It was plausibly argued by sociologists, psychologists, and even philosophers of science that teams composed of people representing diverse standpoints, deriving from diverse identities and life experiences, were better at solving problems than more homogeneous groupings.¹⁵ Like the workers in the pin factory, or the organs of the body, each member of the diverse team was perceived to contribute something unique and essential to the success of the whole. Analogies between cultural diversity and biodiversity became commonplace.¹⁶ And especially in the visual representations of the value of diversity-as-justice, the older tradition of diversity-as-beauty also surfaced. In one of his many rhetorical variations on the rainbow-nation theme, Mandela conjured images that eerily recall Pliny's paean to the diversity of flowers:

Each of us is as intimately attached to the soil of this beautiful country as are the famous jacaranda trees of Pretoria and the mimosa trees of the buschveld – a rainbow nation at peace with itself and the world.¹⁷

Nestled in the heart of the political value of diversity-as-justice still lies the multi-colored splendor of the flowering meadow, here re-imagined as lavender jacarandas and yellow mimosas: diversity-as-beauty. Standing on the shoulders of the older values of diversity, the irresistible rise of the value of diversity-as-justice is perhaps not so mysterious after all.

IV. A Value Is a Value Is a Value

I began with two questions: what kind of value is diversity? And what does the answer to that question teach us about the nature of value more generally? The answer that emerges from the long history that I've sketched is that diversity is not one but several values: a value of beauty, a value of efficiency, and a value of justice. These various normative valences are cumulative: in the nineteenth century, the value of efficiency was added to the ancient value of beauty, and in the late twentieth century, the value of justice was added to the long-established values of beauty and efficiency.

Does the history of the wandering value of diversity teach us anything about value in general? It would be rash to generalize from one example, however long-lived and widespread. Philosophers have long since abandoned the hope that the good, the true, and the beautiful might all turn out to be variants of the same thing, and modern philosophy has divided the territory of values into separate nations, each an island unto itself. There are the utilitarian values of efficiency and productivity, the aesthetic values of beauty and creativity, the epistemic values of truth and objectivity, and the ethical values of justice and inclusion. Officially, there is no traffic among these island nations; each recognizes only the currency of its own distinctive brand of value. At the very least, the history of the wandering value of diversity ought to alert us to the fact that the boundaries between the realms of aesthetics and utility, ethics and epistemology are not watertight, and that there is some cross-border smuggling going on. Value in one realm may confer value in another, however illegitimately from a strictly philosophical point of view. But then, we historians exist to remind the philosophers that there are more things in heaven and earth than have been heard of in their philosophy.

Acknowledgements

Warm thanks to the Institut des études avancées and its staff for their gracious hospitality and to my fellow fellows for stimulating conversations.