If we want to talk about the future of history, we need to ask why we do it in the first place. "The beast lives ahistorically," Nietzsche mused one day, as he watched cows grazing in a pasture. Cattle have a natural history every bit as rich as humanity's. But Nietzsche was getting at something different, which is that cattle are not aware of their own history. From this it follows that all who choose to live without history lead bovine lives. Try that out on the next person who questions your commitment to the past.

For most of us, the point is rather obvious, and we look elsewhere to answer the question of why history. History pursues justice for those who have been denied it. We defend the integrity of the past from those who distort it for political ends. The practice of history enables us to contemplate the status quo with clear eyes and allows us to engage in self-critique. In all these ways, history is about power, place, and identity.

But for me and for many of my students, history is also about the question that cattle cannot ask: How did we get here from there? To date, our answers have been less than they could be, owing to a failure of the chronological imagination. A century ago, as the question was emerging as one of the projects of history, it was already known that the human past was very deep. Contemplating the fact of deep human time, a few historians suggested that the answer could only make sense by taking the long view. But history did not make this turn. We chose to ignore events that unfolded over long time-scales. The enduring puzzle is how we ever imagined that the answers to the big question could be framed in shallow time.

The shallow history practiced for much of the 20th century assigned humanity to its own time, the time of history. Shallow history distinguished geological, biological, and evolutionary processes, unfolding ponderously in slow earth-time, from human cultural processes, dancing along in quick time. Combining the two was like trying to swat a fly with your car. But now, in the 21st century, we face anthropogenic global warming, overpopulation, environmental stress—and the car's bumper has crushed the fly against the wall of the garage. How did this happen?

Well, it turns out that geological and environmental processes can take place within human time scales. We have learned that humans, acting not as individuals, not as groups or nations, but as a species, can dance to the music of the earth's time. In history's future, we will need to learn how to play with the discordant scales of time, from the observational platforms appropriate to each.

Some of the platforms from which we view the past are up there in the clouds. From this vantage point, only broad patterns are visible and individuals are just dots. Other vantage points are down in the trenches, where ecological or social-historical patterns become invisible and all we see is agency. Observers, or at least those who do not avail themselves of ladders, are sometimes rash enough to claim truth status for the view that they happen to see. But there is no truth to be seen from any vantage point, only differences of scale. To resolve this tension, it is urgent that we find ways to resolve the scalar gap that separates large aggregate patterns from the tiny human choices out of which those patterns are made. In our future, we need to learn how to do the work of history at multiple scales.

Deep histories necessarily operate at a distance. Even so, they bring history's political commitments into sharp relief. By setting trends like global warming, growing toxicity, overconsumption, and poverty against the canvas of the past, deep histories highlight the scope of the challenge. The urgency of the contemporary situation, moreover, exposes the inadequacy of the short view.

Shallow history was predicated on the idea that at a certain moment in time, humanity broke through nature's chains, gained mastery, and through the conquest of nature took the momentous step into history. But the triumphalist narrative that undergirds this thinking is just bad. Species are tuned to their environment, but they in turn act upon their own environment in a continuous spiral of mutual influence. The process of niche construction, as this is known, is a dialectical or coevolutionary process. The dialectic between humanity and our niche is not visible except in deep time, for the mechanism describes a relationship in which there is no master or servant, no subject or object, only a pair of agents engaged in a dynamic without discernible origin.

This kind of thinking is vital if we hope to escape from the shadow of our own misunderstandings of what biology is. At its heart, biology is the science of the lack of fixity of form. It springs from the premise that nothing on this earth is bound to the shape or the structure by which it is currently defined. Biology, in short, is a science of the contingent. Its affinities with history run deep. Over the last few decades, misunderstandings have conspired to separate us from biology. The fields went their separate ways, not realizing how much they were borrowing from the same understandings of change and form. Happily, there are good reasons to believe that in the future we can surmount these misunderstandings.

Working alone, historians cannot solve the problems that bear down upon us. Yet by developing a clear-eyed understanding of the trajectories, we can underscore the moral urgency of the situation. To engage in this way, some of us will need to collaborate with colleagues in the sciences. At stake here is not the fact that historians are supposedly illiterate in the sciences; after all, we can learn to recruit students who are interested in these things. The problem is that our colleagues in the sciences, who are smart and interesting people, need help to do the work of history. It is our job to supply the history, and high time that we accept that responsibility.

For some of us, at least, the future of history will also ask us to interrogate our commitments to area studies programs and, with them, to the spatiotemporal fields that define, and constrain, the range of our interests. Area studies have many merits, but they have contributed to the centrifugal tendencies that have torn our discipline apart like no other. If history is to have any future, it is surely a future in which we learn to collaborate among ourselves—not just across space, as transnational or global historians already do, but also across time.

One thing I am sure of is that history will have many futures. Gazing across the chicken run of our practice, I never expect to see the heads of a thousand chickens, all exactly alike. I want to see Speckled Sussex, Plymouth Rocks, Rhode Island Reds, and many others, all cocking an eye at their roost mates with the mixture of benevolence, indifference, and benign contempt that defines so many human relations. History is the undisciplined discipline. Our strength, and therefore our future, depends on preserving a happy and fecund heterogeneity.

Daniel Lord Smail is professor of history at Harvard University. He is the author of The Consumption of Justice: Emotions, Publicity, and Legal Culture in Marseille, 1264–1423 and On Deep History and the Brain.