What do historians do? In a free society, historians have an important responsibility. They are custodians of the public memory, trained to carefully and critically reconstruct how things happened in the past. They help us understand ourselves and the world in which we live. The German historian Johann Droysen put it quite simply: “History is the ‘Know Thyself’ of humanity – the self-consciousness of mankind.”Footnote ¹ Historical knowledge orients us and tells us how we arrived at our present situation – where we came from, how we got here, who we are. To understand who we are, we have to understand who we’ve been. We learn our identity. It steadies us. It has been said that people who lack knowledge of their own history are like cut flowers, lacking a root system to sustain them. The historian William McNeill suggested that people who are ignorant of their history are akin to an individual with a defective memory. Think of waking up some morning unable to remember who you are! Disoriented and uncertain about your past, you would be unable to make informed choices about the future.Footnote ²

Knowledge of the past helps us learn what influences shaped us, what errors or mishaps could have been avoided, what patterns are discernible, and what lessons may be learned for future use. With such understanding we can better prepare for the future. Not that we can predict the future, not that history repeats itself, but rather that it enlarges our perspective, broadens our horizons, and sensitizes us to the ways in which human events unfold. We learn to expect surprises, contingencies, and unexpected consequences.

The integrity of historical knowledge is vital for an informed citizenry and democratic governance. From the time of their founding, Sophia Rosenfeld writes in her Democracy and Truth, governments “premised on the idea of self-rule typically depend on the idea that the people should not be deceived, that veracity and authenticity matter as moral qualities for all.”Footnote ³ An accurate knowledge of the past is critical to the choices that citizens must make in determining public policy. A widely shared collective memory is the foundation of a stable society. “A realistic understanding of the past,” the historian Bernard Bailyn stressed, “free of myths, wish-fulfillments, and partisan delusions, is essential for social sanity.”Footnote ⁴ This is what I meant when I wrote that history steadies us.

As Joyce Appleby, Lynn Hunt, and Margaret Jacob write, “Historians support the long-term goals of democratic societies when they insistently and honestly reconstruct past experience.” They can save us from myths about our identities. Diverse groups may try to maintain their own view of the past whether to serve their self-interest or simply to accommodate their pride. Nation-states build idealized versions of their past to instill civic pride. In the face of such popular and patriotic versions, it is the role of historians to maintain independent scholarly inquiry. “Democracy and history always live in a kind of tension with each other. Nations use history to build a sense of national identity, pitting the demands for stories that build solidarity against open-ended scholarly inquiry that can trample on cherished illusions.”Footnote ⁵

We are all familiar with the importance of a free press in protecting democracy by holding those in power to account. By the same token, the role of a robust historical profession in a critical examination of the past is fundamental to the health of a democratic society. There have long been arguments over how to tell the American story. They are very much with us today. When President George H. W. Bush initiated a plan to establish the first-ever national standards for what schools should teach about the national past it turned into a bitter controversy. More recently, controversy has surrounded the teaching of the history of slavery and race in America.Footnote ⁶ So, too, one of the major issues in telling the American story is how to explain our use of the atomic bomb on Japan.

As we will discuss in the succeeding chapters, historical study of Hiroshima has been a challenge to Americans’ self-image as a virtuous nation. In the Introduction, we discussed how the Smithsonian Institution’s exhibition became embroiled in controversy. Veterans groups and their supporters in Congress argued for a patriotic interpretation of the Hiroshima decision. They saw the proper role of the Smithsonian as memorializing the nation’s victories and not questioning its past. In the end, the text was discarded and the exhibition was curtailed. But shielding Americans from engaging the difficult issues is not beneficial to a democracy.

Attempts to control the writing of history pose a recurrent threat to democratic societies. We live in an age of rampant disinformation, which challenges people’s ability to distinguish fact from falsehood. “Blatant lying about history,” writes Lynn Hunt, “has become more common owing to the influence of social media.” Whether it is about the Holocaust or the birthplace of Barack Obama, “the world-wide web has enabled historical lies to flourish.”Footnote ⁷ Historians may differ in their interpretation of evidence about the past, but to the best of their ability they must stick to what is found to be factually accurate. As a community of scholars united by common purposes and values, historians are enjoined to practice their craft with integrity so as to preserve their reputation for trustworthiness. “It is their single most precious asset.”Footnote ⁸ When a democracy loses its collective trust in common knowledge it undermines cooperation and weakens the institutions upon which democratic politics depends. The philosopher Hannah Arendt wrote in The Origins of Totalitarianism, “The ideal subject of totalitarian rule is not the convinced Nazi or the convinced Communist, but people for whom the distinction between fact and fiction (i.e., the reality of experience) and the distinction between true and false (i.e., the standards of thought) no longer exist.”Footnote ⁹ Losing the ability to tell truth from untruth, the civic life of a democracy loses its equilibrium, its respect for the norms and values that make it work. The study of history contributes to the civic virtue that is the foundation of democracy. “Democracy,” the historian Timothy Snyder writes, “requires individual responsibility, which is impossible without critical history. It thrives in a spirit of self-awareness and self-correction. Authoritarianism, on the other hand, is infantilizing. We should not have to feel any negative emotions; difficult subjects should be kept from us.” Authoritarian governments guide the public memory by asserting a mandatory view of the past. History is made to serve the national interest. War on history becomes a war on democracy.Footnote ¹⁰

There is no greater testimony to the value of historians’ work in a free society than to compare it with what happens in totalitarian regimes where critical historical inquiry ceases. Those regimes go to great lengths to manipulate history and restrict the work of historians. The pursuit of truth through the writing of history cannot be permitted. Authoritarian societies impose a master narrative of the past that meets the needs of the state. Pressed into the service of the state, history becomes a means of indoctrination and securing the legitimacy of the rulers. George Orwell saw this more clearly than anyone. Readers of his novel 1984 will remember the wretched protagonist Winston Smith who kept the records according to the ruling party line in the Ministry of Truth. The Commissar instructs Smith what his responsibility must be. “We the Party, control all records, and we control all memories. Then we control the past, do we not?” Warming to his point, the Commissar quotes the Party slogan: “Who controls the past controls the future; who controls the present controls the past.”Footnote ¹¹ Without memory of the past, the people will believe whatever the Party may tell them.

Writing his novel in 1949 and living in the shadow of Hitler and Stalin, Orwell feared the time when history would again be willfully manipulated in still more extreme ways. Authoritarian regimes would rewrite history to obliterate from memory public figures, heroes, and events that challenge government policies. In our own time, we are witnessing the Chinese Communist Party revise history to erase from memory events such as the Tiananmen uprising and the cruelties of the Mao era and thereby to establish with the new technology control over the future. For the Chinese leadership, the journalist Ian Johnson writes, “the first priority is controlling the past … . To make sure that history really appears to be on its side, the party spends an inordinate amount of time writing and rewriting it and preventing others from wielding their pens.”Footnote ¹² This authoritarian control of the past is becoming the nightmare that Orwell feared.

The Historian’s Craft

How are historians in a free society trained to meet their responsibilities as custodians of the collective memory? Writing history is considered a craft. Like other crafts, it has skills that have been developed and passed on from master to apprentice. The idea comes directly from medieval German guilds “where admittance required that one had trained under a master craftsman and had also produced an original piece of work, hence the word ‘masterpiece.’”Footnote ¹³ As an academic discipline, these skills can be taught by guild-like training in graduate school study. In professional training, one learns certain techniques – the quasi-scientific aspects of how to analyze documents, treat sources critically, weigh evidence, document sources, and develop narrative skills.Footnote ¹⁴ Above all, training in the guild is focused on historiography, critical study of the secondary literature, and learning what is already known and what are the existing issues and interpretations. As the body of knowledge has grown, training requires specialization in one of the many subfields of history, such as social history or cultural history. Also, historians’ training demands knowledge of ancillary disciplines such as economics or the acquisition of necessary foreign language capability. One also learns from observing the skills of highly regarded historians. Gifted craftsmen acquire, or may be born with, the art of representing the past in ways that bring it to life. In the hands of a master craftsman, history becomes an art. It becomes akin to literature.

Professionalization of the Craft

Prior to the nineteenth century, for two thousand years, writing history was the work of amateurs, people who had another occupation but decided to write about happenings that attracted their interest.Footnote ¹⁵ Thucydides, who had been a military leader, decided to write about the Peloponnesian War in which he had participated. For centuries, history writing was an avocation or a handmaiden of literature, theology, or philosophy. Only in the industrial era as universities became more developed centers of learning did history begin to have a systematic methodology and autonomous purpose. In the German universities of the nineteenth century, the study of history was professionalized under the influence of Leopold von Ranke, who said that his intention was to structure the past “as it actually was” or “as it essentially was” (wie es eigentlich gewesen). History became an academic discipline and training for the craft began to be developed. It was to do this by the scientific ideal of relying on the archives, the written records, and eyewitness accounts from the period being studied. History was to be less storytelling and instead must be a rigorous science written by professionally trained historians. Their goal was an objective and impartial rendering of the past.

The first American professional historians embraced the scientific ideal, what one called a “noble dream” that their profession could fulfill a mission of achieving objective truth. Objectivity became “the founding myth of the [American] historical profession.”Footnote ¹⁶ For the founders of the American Historical Association (AHA) in 1884, history was a science that demanded rigorous pursuit of facts, scrupulous research, long hours spent in archives, critical appraisal of the sources, uncovering the facts that the original documents had to reveal. Historians would be objective and detached in relation to their materials. They would explain precisely what happened, free from their personal biases. History would be on “a footing comparable to that of the natural sciences.”Footnote ¹⁷ Their “scientific history tended toward a rigid factualism.”Footnote ¹⁸ The historian, one said at the time, must “collect facts, view them objectively, and arrange them as the facts themselves demanded.”Footnote ¹⁹ The reward of such scientific rigors, they believed, would eventually be a definitive understanding of what actually happened in the past. How stunned they would be if they could foresee the inexhaustible controversy over the Hiroshima decision and the endless interpretations historians continue to offer of the facts.

Can the Past Be Known?

In time, the hope of the first professional historians of achieving objective truth in their writing faced growing doubts. Was it really possible for historians to “extinguish the self,” as Ranke wished, and write an objective account of past events?Footnote ²⁰ The word “history” has two meanings. It refers to what happened in the past, but it also refers to what historians write about the past. They are not the same. And that is the problem. Historians can never fully recapture the past. It is too complex. Historians will each see it in a different way, depending upon their own personal makeup. Their version of the past will be an interpretation, one that is partial, provisional, and incomplete.

In the wake of World War I, historians had growing doubts about history as a “science.” Controversies over their competing and conflicting interpretations of the war and other past events strained the belief that historians could attain objective truth. There were too many disagreements. By the 1930s the confidence that historians could be impartial and detached in construction of the past was widely challenged. In his presidential address to the AHA in 1931, Charles Beard mocked the “noble dream” that it was possible to be objective in reconstructing the past. “Every student of history knows that his colleagues have been influenced in their selection and ordering of materials by their biases, prejudices, beliefs, affections, general upbringing, and experience.”Footnote ²¹ Beard’s contemporary Carl Becker used the memorable phrase “everyman his own historian” to subsume his thesis that history is “an imaginative creation, a personal possession which each one of us, Mr. Everyman, fashions out of his individual experience, adapts to his practical or emotional needs, and adorns as well as may be to suit his aesthetic tastes.”Footnote ²² The past is continually revised. “Every generation, our own included, will, must inevitably, understand the past and anticipate the future in the light of its own restricted experience, must inevitably play on the dead whatever tricks it finds necessary for its own peace of mind.”Footnote ²³ Beard and Becker took obvious pleasure in dispelling the noble dream. Historians may agree on basic facts about the past, but the meaning of the facts begins when historians interpret them. Facts don’t speak for themselves. Facts are inert until something is made of them. From Beard and Becker’s time on, the hope that historians could be so detached as to achieve objective reality in their reconstruction of the past faded.

Conscientious historians can strive – the conscientious historian must strive – to describe and interpret as faithfully as possible the actuality of what happened, but one inevitably falls short. Try as they must for a disinterested and dispassionate approach to their subject, their judgments will still be influenced by their own times. The problems they choose to study, the evidence they select to emphasize, and the perspective they have are to some degree relative to their own time.

Doubts about the possibility of achieving objective truth continued to mount beyond what Beard, Becker, and other critics had argued. In the post–World War II period a new set of theoretical doubts about the nature of historical knowledge arrived as the school of “postmodernism.” Originally formulated by French philosophers Jacques Derrida and Michael Foucault, postmodernism as found in the work of Hayden White and other historians became the most controversial and extreme critique of the possibility of objectivity. “One must face the fact,” wrote White, “that, when it comes to the historical record, there are no grounds to be found in the record itself of preferring one way of construing its meaning rather than another.”Footnote ²⁴ Historians are not uncovering the past, they are inventing it. There is no such thing as objective truth. One perspective is as good as another. By such reckoning, history is storytelling. History is akin to literature, historians to novelists. Each is telling a story as he or she sees it. All interpretations are equally valid. There cannot be any such thing as historical truth. All versions of the past are subjective, the product of one individual’s mind.

A further reason for doubt about the goal of objectivity emerges from the neurosciences, cognitive psychology, and clinical medicine.Footnote ²⁵ Research on the complex ways the brain stores memory suggests that the evidence of eyewitness accounts must always be treated with caution by historians. Conflicting testimonies of the same event by eyewitnesses in judicial courts are common and suggestive of this caution that historians must adopt along with legal experts. Such testimonies are reminiscent of “the Rashomon effect.”Footnote ²⁶ Akira Kurosawa’s 1950 film Rashomon, one of the most famous films ever made, illustrates the problem of conflicting testimonies. Set near Kyoto at the end of the Heian period (794–1185), it is about a bandit who proudly confesses to killing a samurai after a sexual encounter with his wife. A woodcutter claims to have witnessed it all. The film consists of a recounting of this crime by four characters in the film, the bandit, the spirit of the samurai (speaking through a medium), his wife, and the woodcutter. But each recounts a different version of events. Each of the versions is plausible but none can be reconciled with the others. Even the witness’s account is subject to doubt. There is no evidence to elevate one account over the others. The mystery is never solved, and the movie leaves the viewers to ponder for themselves the persuasiveness of the different versions and the veracity of the storytellers. “Thus,” as a Japanese encyclopedia concluded, “truth is revealed as relative and reality itself is questioned.”Footnote ²⁷

In addition to postmodernism, other new approaches to the study of history emerged in the postwar period. History writing had once focused largely on past politics, but a growing number of historians turned their attention to groups in society estranged from power and influence, individuals and groups previously neglected and oftentimes voiceless. By far the most impactful of the new developments was women’s history, first formulated during the 1970s, which challenged the masculinist assumptions of academic knowledge. It soon moved on to incorporate men in its scope. “Those who worried that women’s studies scholarship focused too narrowly and separately on women,” the American historian Joan Scott wrote, “used the term ‘gender’ to introduce a relational notion into our analytic vocabulary.”Footnote ²⁸ As its implications have been pursued, for example in power relations, gender history has had an impact on historical writing comparable to the Marxist history’s attention to “class.” (The birth of women’s studies in the 1970s was a reflection of the professional makeup of the time. When I was appointed assistant professor of history at the University of Washington in 1965 there was only one woman tenured in the department. Today, women make up the majority of tenured appointments in the department, and the chair is a woman.) In his tracing of the development of the American historical profession, Peter Novick concluded that by the 1980s there were now so many different approaches, and so many subfields, that the profession was losing its coherence.

More new approaches continue to emerge. The Indian historian Dipesh Chakrabarty, writing in 2000, complained that historical scholarship has not outgrown the age of Western imperialism. Professional scholarship has been dominated by “Eurocentric” tendencies reflecting Western academics failing to take seriously the traditions of historical writing outside of Europe as worthy of their attention. As Lynn Hunt wrote, “neither history nor the concern for historical truth is Western.”Footnote ²⁹ Japanese, in fact, had argued in the 1890s that study of the history of the East (tōyōshi) was of equal importance as Western history (seiyōshi).Footnote ³⁰ Chakrabarty contended that Western academics remained ignorant of non-Western historical writing.

What then are we to conclude? If there are so many doubts about the ability of historians to discover the reality of the past, to write objective accounts of what happened, what value is history? If Beard and Becker succeeded in dispelling the noble dream of history as a science, if postmodernists can legitimately claim that history is no more than a form of literature and storytelling, if neuroscientists cast doubt on the reliability of memory, if historians can find no agreement on their approaches, should we then question the value of the historical profession? By no means!

The British historian Richard Evans liked E. H. Carr’s observation that “It does not follow that because a mountain appears to take on a different shape from different angles of vision, it has objectively either no shape at all or an infinity of shapes.”Footnote ³¹ Most historians, as John Tosh wrote in his study of the profession, disregarded the extreme view.Footnote ³² John Lewis Gaddis in his Landscape of History shrugged off the claims of postmodernism. He wrote, “Post modernist insights about the relative character of all historical judgments – the inseparability of the observer from the observed – … some of us feel that we’ve known this all along.”Footnote ³³ In sum, as the historian Sarah Maza observed, “The crisis around postmodernism was merely the final stage in a longer evolution away from an earlier belief that a stance of complete objectivity toward their material was, for historians, both possible and the ultimate professional goal.”Footnote ³⁴

Coming to accept the obstacles to a pure objective recounting of the past, historians recognized that knowledge of the past could advance by defending their interpretation within a community of scholars in which they could discuss, debate, and persuade others of their views. They formed professional institutions and set norms and practices to govern their profession. To hold themselves accountable, they established journals in which peer reviews of their work were published. Conferences were organized where interpretations could be debated and discussed. In such ways, the craft accepted that historical knowledge would progress through the work of a community of scholars.

Today, few, if any, historians would disagree that objective reality is an unattainable goal. None, wrote Bernard Bailyn, would be so naive as to “dream that a historian can contemplate the past from some immaculate cosmic perch, free from the prejudices, assumptions, and biases of one’s own time, place, and personality; none of whom deny that facts are inert and meaningless until mobilized by an inquiring mind, and hence that all knowledge of the past is interpretive knowledge.”Footnote ³⁵ While acknowledging that their work cannot recapture the past as it actually happened, the vast majority of historians reject the skepticism of those who argue that all accounts of the past are simply individual inventions. As we trace the debate over the Hiroshima decision, we will have opportunity to see how interpretations are argued and critiqued by other historians and how that process advances historical knowledge.

An Argument without End

For the theologian Soren Kierkegaard, “the pure truth is for God alone. What is given to us is the pursuit of truth.”Footnote ³⁶ Similarly, the eminent Dutch historian Pieter Geyl described the search for historical “truth.” Early in World War II when Europe fell to the Nazis, Geyl began thinking of the parallels between Napoleon and Hitler. Because he was under German surveillance, Geyl could not write about Hitler. Instead, he wrote a remarkable book, Napoleon For and Against, studying how a succession of leading French historians over more than a century had interpreted Napoleon differently. His study of the historical debates over Napoleon from his fall in 1814 down to Geyl’s day found how the divergent portraits of Napoleon were influenced by the personal background of historians and their views on the political and ideological controversies of their own times – in short, the influence of the present on the past in the writing of history. Geyl wrote that the scientific method can help to establish a substantial factual basis about which historians can agree. But once the historian turns to interpretation, it is unavoidable that “the personal element [of the historian] can no longer be ruled out, that point of view which is determined by the circumstances of his time and by his own preconceptions.” One should not find it disillusioning or even surprising, Geyl wrote, that there seemed no finality or agreement in viewing Napoleon’s character and achievements. “No human intelligence could hope to bring together the overwhelming multiplicity of data and of factors, of forces and of movements, and from them establish the true, one might almost say, the divine, balance. … Truth, though for God it may be One, assumes many shapes” to mere mortals. Truth would always be partial and relative. “History,” Geyl concluded, “is indeed an argument without end.”Footnote ³⁷

We will approach the decision to use the atomic bomb much as Geyl approached the historiography of Napoleon. We will see how historians’ views of the Hiroshima decision have been influenced by their personal background and the political and ideological controversies of their own times. And we will find many reasons to agree with Geyl’s conclusion that history is an “argument without end.” That, we will discover, is the way historical knowledge progresses. From the clash of conflicting interpretations comes deeper understanding of the issues and problems, but historians’ debates will not achieve ultimate truth. Historians must be committed to the pursuit of objective truth even while acknowledging that it is elusive, and that perfect objectivity is impossible.