1 Introduction

The epigraphs capture the central claim of this essay: that good education and research depend on a balance between detail and generality, between sharply-focused research, and the unifying intellectual frameworks that help us make sense of, and find meaning in, detailed research.

When Darwin wrote, the need for such a balance was well understood, and his own career offers a spectacular example of the extraordinary synergies that can be generated by connecting detailed research to deep, unifying ideas. Schrödinger wrote just after World War II, when scholars in most fields had abandoned the search for unifying ideas. His comment is a plea to re-establish a lost balance.

Today, we still live in an unbalanced scholarly world in which research normally means sharply focussed enquiry within the boundaries of particular disciplines. In such a world, research that tries to link ideas across many disciplines looks extreme, and (a bit like extreme sports) it can seem over-ambitious and unrealistic. But such projects seem extreme today only because of the emergence, early in the twentieth century, of structures that partitioned teaching and research between distinct scholarly disciplines. That change was so swift and so decisive that today few scholars show any interest in the unifying projects that were once the complement to all detailed research.

2 Coherent Worlds of Knowledge Before the Twentieth Century

So complete was the disappearance of the ancient quest for intellectual unity and harmony, that it can come as a shock to realize how important such unifying projects were for much of human intellectual history, and how recently they lost their centrality in most fields of scholarship.

Almost all human societies have constructed origin stories or creation myths: large, inter-linked collections of stories that summarize a community’s best understanding of how things came to be as they are, by harmonizing many different types of knowledge.Footnote 1 Whether in small-scale societies with ancient oral traditions built up over many generations, or in societies with writing and institutionalized religious traditions, origin stories were powerful because they summed over a society’s core understandings of reality. Origin stories shaped identities because they told you who you were, what you were part of, what roles you could play, and what roles you should play, so they usually structured how young people were educated.Footnote 2 As Marie-Louise von Franz (1995, Ch. 1) argues, creation myths “refer to the most basic problems of human life, for they are concerned with the ultimate meaning, not only of our existence, but of the existence of the whole cosmos.” To take one random illustration, the thought world of Isaac Newton was framed from childhood to old age by the origin stories embedded within Christianity, and Newton’s science flourished within these unifying stories. He thought of God as the “first cause”, and once described the Universe as “the Sensorium of a Being incorporeal, living, and intelligent” (Westfall 1993, p. 259).Footnote 3

It is important to avoid the common error of assuming that unifying projects must suppress diversity and dissidence. This was never true. Origin stories were always capacious enough to allow for disagreement. Isaac Newton, though a devout Christian, opposed the doctrine of the Trinity and was, technically (and discreetly) an “Arian”, a denier of Christ’s divinity (Westfall 1993). Similar tensions existed within all origin stories, and all religious and philosophical traditions. Indeed, as with modern scientific paradigms, it was the sharing of fundamental ideas that gave salience and significance to differences in interpretation, and sometimes made them worth fighting over. Modern descriptions of all “grand narratives” or unifying projects as necessarily monolithic and unchanging are simplistic caricatures.Footnote 4

As modern science emerged, it re-directed the quest for intellectual harmony and unity. The pioneers of modern science, and the major thinkers of the Enlightenment era, aspired to a new understanding of reality, and origin stories that would be based not on tradition, faith or authority, but on Reason and empirical research. “[W]e in effect propose a compleat system of the sciences,” wrote David Hume (1739, Introduction) “built on a foundation almost entirely new, and the only one upon which they can stand with any security.” Science, they believed, would set new standards for reliable knowledge, and release humanity from naïve trust in faith or authority. “Enlightenment,” wrote Immanuel Kant (1794), “is man’s release from his self-incurred tutelage [literally, Unmündigkeit, or “minority”]… [his] inability to make use of his understanding without direction from another. … Sapere aude! ‘Have courage to use your own reason!’- that is the motto of enlightenment.” Most Enlightenment thinkers were convinced that a better and more coherent understanding of reality would advance the progress of humanity as a whole (Pagden 2013, pp. 147 ff).

It is possible to identify two overlapping colours or qualities to the Enlightenment’s unifying project, and it may be that the same two colours can be identified in all origin stories.Footnote 5 The first approach emphasises historical or narrative coherence, so it tends to take the form of stories or histories. It assembles diverse types of knowledge, like so many coloured tiles or pixels, into coherent accounts of how things came to be. Such narratives can be found at the heart of most religious traditions. The second approach can also yield large unifying narratives, but its primary emphasis is on conceptual unity, on the search for networks of ideas that are locked together tightly enough to provide a foundation for most of knowledge. Traditionally, this approach has shaped much theological, philosophical and mathematical thought, and today it can be found in unifying ideas such as General Relativity or Quantum Physics. The two approaches have always overlapped and reinforced each other. Thus, all the world religions contain large stories linked to logically rigorous foundational systems of ideas about how the Universe works.

The search for a science-based origin story flourished in Europe from the early eighteenth century. The search for conceptual unification drove the great intellectual systems of the nineteenth century, those of Hegel, Comte, Marx, Spencer and many others, though most of these systems also generated grand historical narratives. The emphasis on narrative unity shaped the natural histories of Buffon or the Universal histories of Voltaire, as well as nineteenth century universal histories, such as Alexander von Humboldt’s multi-volume Kosmos, or Robert Chambers’ Vestiges of the Natural History of Creation, which would have a profound influence on Charles Darwin (Spier 2008).Footnote 6 The deep desire to keep in touch with the underlying unity of life and the universe also drove much of the Romantic reaction against what they saw as the arid scientism and the extreme focus on detail of some scientific thought.

The quest for intellectual unity still flourished in the late nineteenth century, in both its conceptual and narrative forms. While James Clerk Maxwell showed that electricity and magnetism were different expressions of the same underlying force, the historian, Leopold von Ranke (often thought of as the primary exemplar of small-scaled historical research) warned against “the danger of losing sight of the universal, of the type of knowledge everyone desires. For history is not simply an academic subject: the knowledge of the history of mankind should be a common property of humanity …”.Footnote 7

3 The Fragmented Knowledge World of the Twentieth Century

Early in the twentieth century, the unifying project vanished like a ghost at dawn. And it vanished so completely that, a century later, it is easy to forget how normal such projects once seemed. Two decades into the twentieth century, most scholarship and research was conducted within the well-policed borders of particular scholarly disciplines, and fewer and fewer scholars were willing or able to look for harmonizing concepts or stories that crossed multiple disciplines.Footnote 8 Those that tried, such as H.G. Wells (1920), were widely regarded as dilettantes, and had little impact on the academy. Suddenly, except in areas such as Physics, where unifying paradigm ideas such as General Relativity flourished, interdisciplinary research and scholarship began to seem extravagant, wasteful and unnecessary: a quaint intellectual hangover from an era in which scholars had not yet grasped their impossibility.

For most of the twentieth century, scholars and researchers inhabited an intellectual world whose borders were as well patrolled as those of modern nation states. An influential 1972 OECD report on interdisciplinarity noted the exclusivity and competitiveness of these new intellectual statelets. Each discipline, it argued, consisted of: “A specific body of teachable knowledge with its own background of education, training, procedures, methods and content areas,” and its own well-defined territories, interests, rituals and leaders, so that they often functioned like “autonomous fiefdoms” (Apostel et al. 1972, p. 9).

The idea of distinct scholarly disciplines is old, of course, as old as the first attempts to describe and certify specialist knowledge and skills. But in the narrower sense referred to here, “disciplines” emerged in the late nineteenth century, along with modern research universities (e.g., Turner 2017). German universities pioneered today’s combination of research and teaching within well-defined discipline borders. But the model was soon copied elsewhere, and, in the early twentieth century it spread throughout the world.

By the end of the nineteenth century a worldwide revolution in practice was beginning, … . The desire to emulate German universities led to the modern university in one country after another. Disciplines developed in association with licensing regulations or their de facto surrogates, and disciplinary organizations developed to define portions of academic turf. By 1910 the modern disciplines, and the modern research university, had been defined (Turner 2017, p. 18).

In many ways, the turn towards extreme disciplinarity was a success. The disciplines provided containers for research agendas that might otherwise have grown unmanageably. Within those safe spaces, research flourished throughout the twentieth century.

But the achievements came at a cost. Discipline-based research flourished, a bit like potted plants, because it was confined. Where thought threatened to sprawl unmanageably, the disciplines pruned over-reaching branches and root systems, creating the intellectual equivalent of a bonsai garden. As Fred Spier puts it: “In the real world, everything has remained connected with everything else. As a result of the ongoing ‘disciplinification’ of universities, however, this important insight, familiar enough to Alexander von Humboldt, was lost” (Spier 2008, p. 144). Modern education blinkered the educated, creating the world of mutually uncomprehending scholarly tribes that C.P. Snow lamented in his famous 1959 Rede lecture on “The Two Cultures” (Snow 1963). In 1963, Snow wrote (p. 60):

Persons educated with the greatest intensity we know can no longer communicate with each other on the plane of their major intellectual concern. This is serious for our creative, intellectual and, above all, our normal life. It is leading us to interpret the past wrongly, to misjudge the present, and to deny our hopes of the future. It is making it difficult or impossible for us to take good action.

In such a world, as Martin Kemp (2009)Footnote 9 wrote: “a gulf of understanding has opened up by the time students enter university.”

The problem is not so much the existence of disciplines, as the fact that the disciplines have tended to block the free movement of ideas. In 1998, E.O. Wilson argued that the borders between disciplines were blocking fundamental research in many areas. The success of research within disciplines was creating more and more dead zones between disciplines, where new questions accumulated only to be ignored by discipline-based researchers, until they withered in an academic no-man’s land of extreme aridity (Fig. 2.1).

Fig. 2.1
figure 1

Why consilience is difficult. Adapted from Wilson (1998, p. 8)

Full size image

Here, each quadrant represents a distinct research world, with its own rules, its own criteria for good research, its own funding mechanisms, journals, and measures of prestige and success. But, he wrote, close to the borders between disciplines, “we find ourselves in an increasingly unstable and disorienting region. The ring closest to the intersection, where most real-world problems exist, is the one in which fundamental analysis is most needed” (Wilson 1998, p. 8). Though vibrant and productive within their boundaries, the disciplines were creating intellectual dead zones at their borders. Insert into Wilson’s diagram other disciplines such as Anthropology, Neuroscience, History, and Primatology and you find, in the dead zone at their borders, the most fundamental question of all for the Humanities: what is it that defines our own species and explains why we are so unusual?

What explains this sudden fragmentation of knowledge that empowered and limited education and research for a century? Increasing government management of education and research, driven by the increased role of governments during the world wars, encouraged a focus on specific problems and a high degree of institutional compartmentalization. But two other powerful forces were also at work: the spectacular increase in new information in the nineteenth century, and scepticism about the failure of earlier attempts at intellectual unification.

Today, it is easy to forget how terrifying and destabilizing was the tsunami of new knowledge created by the earthquake of industrialization. In a famous passage in the Communist Manifesto, Marx and Engels wrote: “All fixed, fast-frozen relations, with their train of ancient and venerable prejudices and opinions, are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned,…” No universal systems or stories seemed robust enough to survive unscathed in a world of such intellectual turmoil, none of the ancient religious or philosophical systems, and not even the more modern systems of the great Enlightenment thinkers. The disciplines provided intellectual shelters from the hurricane of new knowledge.

The second reason for abandoning the unifying projects of the Enlightenment was that none of these projects really worked. The success of Newton’s system was not matched in history or sociology or even in the sciences, and early in the twentieth century Einstein showed that even Newton’s physics needed adjusting. Besides, the French Revolutionary Terror, and the bloody history of the nineteenth century undermined the Enlightenment’s intellectual optimism, by showing that Reason, science and new types of knowledge could serve oppression as well as progress. Scepticism was magnified by the world wars of the early twentieth century and the rise of totalitarian systems sustained by science and claiming to be built on Reason. One of the most influential modern critiques of Enlightenment thought, Horkheimer and Adorno’s (2002) Dialectic of Enlightenment, was written in the shadow of the Nazi death camps, which had put modern scientific knowledge to the most evil of ends.

In retrospect, most of the large nineteenth century systems and unifying stories do indeed look more like ideologies than science. That was because the science behind them was too thin to build robust intellectual systems, and had to be padded out with much speculative wadding. Though the nineteenth century did yield powerful unifying ideas, such as Darwin’s theory of evolution, or Maxwell’s unification of electricity and magnetism, there also appeared many pseudo-scientific systems of thought, such as phrenology, or Social Darwinism. These undermined the credibility of the Enlightenment project, and encouraged a turning away from unifying schema towards less ambitious scholarly agendas. The retreat from unifying projects was almost universal in the Humanities disciplines, which lacked the paradigm ideas that kept hopes of unification alive in the natural sciences. Historians reacted against the “scientific history” of Marx and his followers. And Anthropologists turned away from pseudo-scientific accounts of human progress, towards detailed studies of particular cultures. “In cleansing historical and cultural analysis of their nineteenth-century ideological baggage,” write Shryock and Smail, “most of the high modern (and postmodern) versions of cultural anthropology and history turned their backs on the deep human past …” (Shryock and Smail 2011, p. 294).

But the structure of distinct disciplines inhibited the search for deep unifying ideas even in the natural sciences. In 1944, Erwin Schrödinger wrote:

… the spread, both in width and depth, of the multifarious branches of knowledge during the last hundred odd years has confronted us with a queer dilemma. We feel clearly that we are only now beginning to acquire reliable material for welding together the sum total of all that is known into a whole; but, on the other hand, it has become next to impossible for a single mind fully to command more than a small specialized portion of it (Schrödinger 2000, p. 1).

4 Critiques of Hyper-Disciplinarity

As this passage suggests, there survived within the fragmented world of distinct scholarly disciplines a deep nostalgia for a lost world of intellectual cohesion. And it may be that the ideal of some sort of universalism survived better beyond the Atlantic world. Marxist traditions in the Soviet Union and China preserved the ideal of universal knowledge, though in forms that were archaic and constricted by censorship; but survival of the ideal may help explain the profoundly inter-disciplinary ideas of Soviet astrobiologists such as Iosif Shklovksy, and geologists such as Vladimir Vernadsky, who pioneered the idea of a biosphere.Footnote 10 And small numbers of scholars in many different parts of the world continued to insist on the importance of transcending discipline boundaries and preserving a sense of the underlying unity of knowledge and research.Footnote 11

In the early twentieth century, and particularly in the Atlantic world, nostalgia for some sort of intellectual coherence shaped much modern art, literature, philosophy and scholarship. Yeats’ poem, “The Second Coming”, captures that nostalgia and the terror of living in a world without intellectual unity or meaning.

Turning and turning in the widening gyre,

The falcon cannot hear the falconer;

Things fall apart; the centre cannot hold;

Mere anarchy is loosed upon the world,

The blood-dimmed tide is loosed, and everywhere,

The ceremony of innocence is drowned;

The best lack all conviction, while the worst

Are full of passionate intensity.

The yearning for a lost intellectual unity drove many scholarly attempts to cross disciplinary borders, but few made much headway because there was now little institutional support for genuinely transdisciplinary research, particularly in Europe and North America. Erwin Schrödinger wrote, forlornly:

I can see no other escape from this dilemma (lest our true aim be lost for ever) than that some of us should venture to embark on a synthesis of facts and theories, albeit with second-hand and incomplete knowledge of some of them–and at the risk of making fools of ourselves (Schrödinger 2000, p. 1).

By the middle of the twentieth century, education, scholarship and research were so deeply embedded within the matrix of disciplines that even the most successful attempts at unification were no longer seen as unifying projects, but as attempts to travel between disciplines. It was the disciplines that now seemed fundamental rather than the networks of knowledge that linked them. Their borders seemed to map reality itself. As Wordsworth, a lifelong seeker of unity, wrote in The Prelude (Book 2):

In weakness we create distinctions, then

Deem that our puny boundaries are things

Which we perceive, and not which we have made.

Attempts to unify knowledge were increasingly described as “interdisciplinary research”. Interest in interdisciplinary research blossomed in the 1960s. The 1972 OECD report on interdisciplinarity that has already been mentioned argued that scepticism about science arose from “specialised applications of knowledge, without a corresponding development of the synthesising framework which can illuminate their side-effects and long-term implications” (Apostel et al. 1972, p. 10). Interest in interdisciplinary research was also driven by new research areas, such as genetics or gender studies, that overflowed existing disciplinary boundaries.

There were also some spectacular examples of the synergies that could be released by interdisciplinary expeditions. Erwin Schrödinger’s attempt to cross disciplines in his book, What is Life? provides a good example. Here was a physicist writing about a fundamental problem in biology. Schrödinger argued that life and reproduction must involve a sort of coding in large molecules, in which a small number of components could be arranged and re-arranged like letters in an alphabet. He suggested, therefore, that the chromosomes inside cell nuclei might each consist of what he called “an aperiodic crystal or solid” (Schrödinger 2000, pp. 60–62). That idea inspired a generation of biologists, including the discoverers of the structure of DNA. Indeed, Francis Crick, though originally a physicist, switched to biology and origin-of-life research after reading Schrödinger’s book (Watson 1973, p. 23).

By the 1970s, there were increasing demands for more interdisciplinary research. The first major conclusion of the influential 1972 OECD report on interdisciplinarity was that: “Interdisciplinary teaching and research are the key innovation points in universities,” in part because interdisciplinarity can “help the drift of science and research towards unity”. But the report’s second major conclusion was that the scholarly disciplines made the quest for unity extremely difficult. “Introducing this innovation comes up against enormous difficulties …”, above all because of “The organization of universities into monodisciplinary Schools or ‘Faculties’ which jealously protect their branch of knowledge …” (Apostel et al. 1972, p. 12).

The mid twentieth century vogue for interdisciplinarity generated new university and research structures and spawned new composite disciplines, such as biochemistry or environmental science. And that is why, today, some forms of interdisciplinary research are familiar and well-funded. But the return to unifying projects was hesitant, partial and limited, and took several different forms. New typologies were constructed to describe different degrees of interdisciplinarity. The most widely used categories have been “Multidisciplinarity”, “Interdisciplinarity” (in a non-generic sense) and “Transdisciplinarity” (Apostel et al. 1972, pp. 25–26).

“Multidisciplinarity” refers to a loose linking of disciplines, often around a common problem or research agenda, while the individual disciplines “… continue to speak as separate voices in encyclopedic alignment. Underlying assumptions are not examined and the status quo remains intact.” “Interdisciplinarity” refers to a closer integration of disciplines that: “integrates separate data, methods, tools, concepts theories and perspectives in order to answer a question, solve a problem, or address a topic that is too broad or complex to be dealt with by one discipline. … in interdisciplinary fields a new body of knowledge emerges” (Klein 2005, pp. 1034–1035; see also Klein 2017).

Finally, “Transdisciplinarity” takes us even closer to the unifying projects of the Enlightenment. Transdisciplinarity refers to an even closer integration of methods and insights from different disciplines that points towards “an over-arching synthesis that transcends the narrow scope of disciplinary worldviews” (Klein 2005, pp. 1034–1035). Julie Klein describes the most ambitious forms of transciplinarity as: “… the epistemological quest for systematic integration of knowledge” (Klein 2017, p. 29). In a world of disciplinary fiefdoms, transdisciplinarity, the most integrated form of interdisciplinary scholarship, made the least headway. It remains rare and poorly funded, and has had a limited impact on most of the Academy, despite the existence of some specially designed transdisciplinary institutions such as the Santa Fe Institute for Complexity studies.

5 The Re-emergence of Unifying Projects from the Late Twentieth Century

Despite all this, in the late twentieth century and early twenty first century there have been some promising signs of a return to the unifying projects of the past.

Transdisciplinary thought and research made most headway in the Natural Sciences, where they were buoyed by new paradigm ideas, including Big Bang Cosmology, the Standard Model of Particle Physics, Plate Tectonics and the modern Darwinian synthesis (see also Crawford 2019; this volume). Some scientists even began to dream of super-paradigms or “Grand Unified Theories” that would capture the fundamental rules by which our Universe was constructed. But the new paradigms also encouraged the quest for narrative coherence, because they were all historical in nature. They all described how the Universe, planet Earth, and life had evolved over vast periods of time. The Harvard astronomer, Harlow Shapley (who once described the splitting of knowledge between disciplines as “education-defeating”; Shapley 1963, p. 134), advocated for university curricula that: “would present the history of the universe and mankind as deduced from geology, cosmogony, paleontology, anthropology, comparative neurology, political history, and so on. … wide integration is the essential key” (Shapley 1963, pp. 135–136). And he was as good as his word, teaching such courses at Harvard for several decades, before his successor, Carl Sagan, built from them a wildly popular television series, “Cosmos.” Similar courses were taught in the Soviet Union by Iosif Shklovksy, in France by Hubert Reeves, and in Austria by Erich Jantsch (Chaisson 2014, p. 87).

In the late twentieth century, several scientists wrote synthetic works that combined conceptual and narrative coherence over large areas of knowledge. They included histories of the Earth by Preston Cloud, histories of the Universe by the astronomers George Field and Eric Chaisson, and the astrophysicists Erich Jantsch and Siegfried Kutter (Spier 2008, p. 144). In the 1990s, Eric Chaisson wrote a history of the Universe built around the central theme of increasing complexity, driven by increasingly dense flows of energy (Chaisson 2001). He called his unifying project “Cosmic Evolution”, using a phrase first introduced in the late 1970s by George Field (see Field et al. 1978; Chaisson 2016). Fred Spier would later offer a theory of universal history that focussed on the emergence of “regimes” or semi-stable structures of many different kinds, an idea that had been partially prefigured in the work of Erich Jantsch (Spier 1996).

Scholars in the Humanities took longer to embark on serious transdisciplinary journeys, partly because the Humanities did not generate paradigm ideas as persuasive as those that emerged within the Natural Sciences. The unifying ideas that did emerge within disciplines such as Economics or Sociology or Archaeology were always contested, unlike some of the big ideas in the natural sciences, which were so widely accepted that they achieved the status of Kuhnian paradigms (Kuhn 1970). The “pre-paradigm” nature of most Humanities disciplines encouraged a focus on specifics, and a deep scepticism about attempts at intellectual unification, or the construction of “grand narratives”.

Nevertheless, even in the Humanities disciplines, there were large, general problems, such as the rapidly increasing human impact on the biosphere, that encouraged some researchers to travel tentatively between disciplines (Klein 2011, p. 15). And the historical narratives emerging within the natural sciences encouraged some scholars to seek links between their own historical narratives and the large-scale narratives emerging within Cosmology, Geology and Palaeontology. Though most historians remained sceptical of the idea of universal history, fearing a return to the unsuccessful historical schema of the nineteenth century, some were attracted by the challenge of linking human history to the emerging histories of the biosphere, planet earth and the Universe as a whole. They were inspired, not only by the new unifying narratives being constructed within the natural sciences, but also by the fact that the science was so much richer and more rigorous than it had been in the nineteenth century. That encouraged hopes for unifying stories free of most of the non-scientific intellectual baggage of the less successful nineteenth century systems.

New dating methods also transformed the task of constructing universal histories. When H.G. Wells (1920) wrote a history of the Universe, he could offer no reliable absolute dates for any event before the first Greek Olympiad. All earlier events disappeared into a chronological fog. In the 1950s, new dating techniques were developed, based on the breakdown of radioactive materials. Radiometric dating allowed the construction of reliable chronologies reaching, eventually, to the origins of the Universe. These dates provided the chronological spine for a rigorous, science-based modern origin story.Footnote 12

To scholars from the Humanities, unification meant, almost inevitably, narrative unification rather than the conceptual unification sought by scholars in the natural sciences. For scholars in the Humanities, the challenge was to link stories told in many different disciplines into a coherent universal account of the past. What larger plot lines could be seen, and what new themes and forms of coherence would emerge if you tried to weave together the stories told by cosmologists, astronomers, geologists, biochemists, palaeontologists, anthropologists and historians?

My own experience of approaching these challenges as a historian may be fairly typical. When I first tried to teach a big history course embracing the whole of time, in 1989, I invited scholars from many different disciplines to lecture on the core ideas of their disciplines. My colleagues and I watched to see what would come out of the mix. What we got was a brilliant tour of modern paradigms alongside a rather loose account of human history. But the stories did not cohere, because lecturers spoke to the major themes of their disciplines, used the methods and jargon with which they were familiar, and had little time to build bridges between disciplines. I began to fear that big history courses would remain “interdisciplinary” in the most limited sense. They could not transcend the disciplines, and could, at best, serve up a sort of intellectual smorgasbord.

Over several years, though, broader plot-lines and a deeper coherence began to appear. It became apparent that one major narrative theme was the emergence of many forms of complexity, at many different scales, from galaxies to viruses to human civilizations. That theme raised deep questions about the creativity of the Universe as a whole, and about the relationship between complexity in the human world and complexity in the biosphere and the Universe as a whole. Watching unifying themes emerge over several years was a bit like watching a developing photograph in the chemical bath of a traditional photographic dark room. And the gradual appearance of unifying themes showed that the difficulties of seeking unified knowledge arose not from the intrinsic difficulties of the project, so much as from the habits of thought that dominated a world of distinct scholarly disciplines.

Since the late twentieth century, many scholars have taken up the challenge of constructing “big histories” or modern origin stories, and they have done so in many different parts of the world which suggests that there is an emerging “global conjuncture” around the idea of such projects (Rodrigue 2017). Today, there is a growing scholarly literature on big history, and big history courses are being taught in a number of universities, mostly in the USA, Australia and the Netherlands. Online courses in big history have also been developed for high schools, through the “Big History Project” (generously supported by Bill Gates) and, in 2018, through “Big History School” (supported by Macquarie University), which includes a Primary School curriculum in big history.Footnote 13

6 New Transdisciplinary Projects and New Research Agendas

The final section of this essay is frankly speculative. If the changes described in the previous section are early signs of a scholarly return to more transdisciplinary research and thought, what impact will this have on the research landscape?

A world in which the unification of knowledge is taken seriously will be intellectually more balanced than today’s world. The disciplines will survive, not just because of institutional inertia, but also because they serve many useful functions. And they will continue to shape research at smaller scales. But as transdisciplinary research becomes more important, the disciplines will have to become more sensitive to developments in neighbouring fields and in scholarship as a whole. Disciplinary boundaries will have to become more flexible, more permeable and more open to transformative changes.

To support, fund, and offer career paths to the increasing number of scholars drawn to transdisciplinary problems, new institutions will be needed to link disciplines and encourage more traffic between them. Amongst those most drawn to unifying projects, something of C.P. Snow’s distinction between the cultures of the sciences and humanities will surely survive. But the differences will no longer arise from mutual incomprehension, but rather from sustained dialogue, in which some scholars will focus mainly on the narrative coherence between different fields, while others focus on the conceptual challenge of teasing out unifying paradigms.

A more unified knowledge world will transform school syllabi. But the changes need not be complex, and most of the existing infrastructure of education will remain in place. Most traditional disciplines will survive. But new, unifying disciplines will emerge, such as “Big History”, which can help students see the underlying coherence of modern knowledge, and the many links between traditional disciplines. Such courses already exist, and they offer students the metaphorical equivalent of a journey to the top of the mountain, from where they can see more clearly what links different disciplines as well as what divides them. If such courses were to become standard components of school curricula throughout the world, they could provide students, as traditional origin stories once did, with a coherent vision that they could take with them into adult life.

In universities, too, teaching within existing disciplines will no longer create intellectual blinkers if students are also exposed to courses that help them see the unity beneath modern disciplines. Such courses are already being taught in many universities, and there already exist rich resources, both printed and electronic, to support their teaching.

A return to the unifying project of the Enlightenment may have its greatest impact in advanced research environments, which is where they have had the least impact so far. Today, scholars attracted by the challenges of transdisciplinary research struggle to gain recognition, to raise funding, and to find scholarly support. But a world that takes such projects more seriously will surely take more seriously the intellectual and institutional challenges faced by those researchers most interested in transdisciplinary research.

What will unifying research projects look like? We already have some answers because paradigm builders such as Darwin and Einstein have shown that there are deep, powerful unifying ideas waiting to be discovered by those who look for them. And there are areas of research where the need for unifying ideas is apparent to everyone, such as the challenge of linking Relativity Theory and Quantum Theory. Both theories work spectacularly well, yet one assumes a granular universe while the other does not. What are we missing? In the Humanities, the question that may drive unifying agendas most powerfully concerns the distinctiveness of our own species. What makes humans different, so different that our species is now dominating change in the biosphere?Footnote 14

These large questions offer good models for unifying research in general, because to pursue them, scholars will have to link methods, insights, concepts, terminology and perspectives from different disciplines. Their task will be to translate between disciplines. Can you translate the concept of entropy, which does extraordinarily powerful work in the natural sciences, into the Humanities? Is the historian’s “decline and fall” similar to the physicist’s “entropy”? Is there enough common ground between the two concepts that, with some tweaking we may find ways of describing entropy that can inform research in the humanities? Much the same is true of concepts like information (do acoustic engineers, quantum theorists, geneticists and historians mean the same thing when they use the word?), or complexity, or energy.

The task is also to tweak how concepts are used at different scales, because many concepts work well at some scales and less well at others (e.g., Christian 2005). One of the most fundamental problems in contemporary science is how to make Quantum Physics work not just at the atomic scale but also at the cosmological scales of relativity? For the historian, concepts such as energy or information are too general to be helpful in most types of historical research, so the abstract concepts do not loom large in historical discussions, though specific forms of energy and information are woven into all historical narratives. Can we link these different levels of explanation, and will doing so prove illuminating? (Christian 2017b). The transdisciplinary challenge here is to check that the concepts used at different levels are aligned logically. That is a bit like assembling a conceptual ladder, all of whose rungs are part of the same system even though particular users may use a small part of the ladder. Or perhaps a better metaphor is a Mandelbrot set, in which each level seems very different from other levels despite some eerie similarities and despite the fact that all levels are generated by the same equation.

There are huge intellectual synergies awaiting scholars who can reformulate fundamental ideas so as to extend their reach and the amount of useful intellectual work they can do. Network theory is another field that promises huge synergies if its methods and ideas can be extended beyond their existing range. I have tried myself to use network theory to understand the accumulation of knowledge within and between different types of human communities (Christian 2004), and the Israeli historian, Irad Malkin, has shown how network theory can illuminate our understanding of ancient Greece (Malkin 2011).

In addition to re-working and extending existing concepts, unifying research projects will surely generate new unifying concepts as well, ideas that can do useful work across large intellectual spaces. Many such ideas already exist. Eric Chaisson has explored the idea that the density of energy flows may provide one way of measuring and explaining different levels of complexity in a Universe in which the upper levels of complexity seem to have increased over time. Is this an idea that can help us make sense of phenomena as diverse as stars, solar systems, cellular life, ecosystems and human history? Fred Spier has argued for the usefulness of the idea of “regimes” in universal history. There have been many attempts to extend the concept of natural selection beyond the biological realm that first generated it, as a way of explaining increasing complexity through what Richard Dawkins describes as Universal Darwinism. In a famous essay called “Blind Variation and Selective Retention”, Donald Campbell (1960) argued that, whatever the domain, evolution needs “a mechanism for introducing variation, a consistent selection process, and a mechanism for preserving and reproducing the selected variations.” Do similar mechanisms explain emerging complexity in human cultures, or even in Cosmology, or in Quantum Physics, as some have argued? (Christian 2014). Whatever answers eventually emerge to such questions, these are rich and profound research agendas that will be very hard to pursue successfully until the world of scholarship returns once more to the unifying projects of the Enlightenment.

Unifying research agendas, requiring plenty of conceptual translation, will also emerge in response to complex, transdisciplinary problems. Environmental history offers a good model, as historians and climatologists and ecologists and scholars in many different fields have reached out towards each other to create what is now a vibrant and strategic transdisciplinary research field. Closely related, and driven by similar synergies, is the rapidly expanding field of “Anthropocene” studies. Understanding the planet-changing impacts of human activities in the twentieth century is a task that requires the sharing of insights and perspectives from historians, economists, climatologists, palaeontologists, biologists, geologists, and more.

These guesses about the research agendas and approaches of a world that takes seriously Schrödinger’s “longing for unified, all-embracing knowledge” are all based on developments that are already apparent. Today’s scholarly world may be slowly recovering the ancient balance between detailed and unifying knowledge. And doing that is increasingly urgent in a world that faces the colossal challenge of managing an entire planet, a challenge that cannot even be seen clearly through the narrow lenses of existing scholarly disciplines. The discipline-based scholarly world of the twentieth century generated such rich knowledge in so many fields that it should now be possible to return to the unifying projects of the Enlightenment, and tackle the new problems of the Anthropocene with a rigour and richness, and a global scholarly reach, that was unthinkable before the twenty first century.