Maybe you feel it too: a creeping sense that the world is going haywire. A darkness spreading across the horizon of our aspirations for our families, our communities, our world. An emerging dismay that possibilities for a good future, for ourselves and our kids, are ebbing away.

If so, your feelings are not without base; they do reflect a real shift in the state of our world. Accumulating scientific evidence and data show that key trendlines gauging humanity’s well-being—economic, social, political, and environmental—have indeed turned sharply downwards.

Just twenty years ago a feeling of exuberance still animated many societies. After the Soviet Union collapsed and before the war on terror, political, business, and intellectual leaders in the West declared that a fusion of capitalism, liberal democracy, and modern science would create a future of near-boundless possibility for all humanity. Now, humanity is at a perilous juncture. Problems like climate change, economic and social inequality, and the risk of nuclear war have become critical. In 2020, COVID-19 stopped the world at large in its tracks. International scientific agencies are issuing report after report declaring that a global environmental catastrophe is imminent, now probably far earlier than 2045, and maybe even as soon as a decade from now. Meanwhile, reason and scientific fact often seem impotent before entrenched vested interests, worsening social polarization, and rising political authoritarianism.

As our prospects seem to diminish by the day, some of us retreat inwards to focus on things close to us in time and space, such as our friends and family, in person and on social media. Others try denial, maybe by claiming that the evidence for problems such as climate change and even pandemics is invented by people who benefit from scaring us. Or, we become fatalistic, declaring we can’t do anything about the problems because we’ve gotten used to a way of living or because the problems are the fault of the rich, or the poor, or immigrants, minorities, or “them over there”—anybody but us. Some of us rally to authoritarian leaders who tell a simple story about what’s wrong and declare they can make things better with bold, harsh action.

Anxiety about the future, detachment, self-deception, and feelings of resentment and helplessness—this is a perilous psychological state—the starting line of a fast track to the end of hope. It also makes the future we fear far more likely to happen, because the best way to ensure we’ll fail to solve our problems is to believe we can’t.

We all know—whether explicitly or unconsciously—that to escape this trap we need to come up with promising ideas to address the critical problems humanity faces. But to do so, we need to understand what’s causing the problems in the first place. As any medical doctor would say, good prescription depends on good diagnosis. To that end, over the last forty years I’ve studied humankind’s global challenges closely, particularly worsening economic insecurity, climate change, pandemics, scarcities of critical resources like fresh water and clean energy, weak and incompetent governance, and the factors that keep our societies from innovating effectively to address such problems. I’ve also studied how these challenges can combine to multiply their total impact, with cascading consequences that sometimes lead to mass violence, including terrorism, genocide, and war.

As a doctoral student at the Massachusetts Institute of Technology in the 1980s, I helped found a research group of young natural scientists, lawyers, and social scientists at MIT, Harvard, and other nearby universities interested in the implications of Earth’s environmental crisis. Our work together was exhilarating—we were all hopeful that science, international goodwill, and basic common sense would prevent humanity from tumbling into an environmental disaster. Today, we’re dispersed all over the world; and with a planetary environmental disaster now unfolding in real time, we remain connected with each other to share information, ideas, and research findings.

Alas, the underlying causes of humanity’s problems aren’t easy to diagnose, and some of the world’s best minds have struggled for decades to figure out what’s going on. Ever since those university years, I’ve followed their research and expert debates with fascination, and my books The Ingenuity Gap (2000) and The Upside of Down (2006) drew on that work to provide a framework for my own research and diagnoses.2 I didn’t pull any punches in my assessment of the dangers, so I was often labeled a “doom-meister.” But as the years have passed, my analysis in those books has (unfortunately) turned out to be close to the mark, and the profound gravity of humanity’s predicament is now hard to miss and broadly acknowledged.

I’ve always intended this third book to move beyond diagnosis to explore what we can do to get through the gloom and reach a new light. I start from the assumption that this is a time for honesty about the challenges we face and about our need for immediate, courageous responses. It’s now vividly apparent to me and my scientific colleagues, to many members of the world’s Indigenous cultures, to socially progressive groups everywhere, to the clear-eyed youth who in 2019 protested for climate action in the streets of more than a hundred countries, and to the countless families and communities worldwide devastated by the psychological and economic trauma of the COVID-19 pandemic the following year, that humanity is marching down a path towards calamity. To find a route to a far better outcome, we must marshal our amazing ability to overcome new challenges—an ability we’ve honed since the first hominid climbed down from the trees and set out across the savannah.

In the following chapters, I draw on insights from history, psychology, physics, philosophy, economics, politics, and art to identify such an alternative route that’s informed by honest realism—one that leads us towards a future of broadly shared opportunity, security, justice, and identity. I also provide some practical scientific tools that we can use to take our first steps together along this radically new path.

I argue that at this crucial moment in humanity’s history, three changes are essential to keep us from descending into intractable, savage violence.

First, we need individually to better understand how and why we see the world the way we do and what makes other people’s views sometimes so different from ours. Second, instead of passively accepting a dystopian image of what will come tomorrow, we need to actively create together from our diverse perspectives a shared story of a positive future—including a shared identity as “we”—that will help us address our common problems and thrive. And, finally, we need to fully mobilize our extraordinary human agency to produce that future.

Each of these changes requires that we have hope. To believe in the possible and to make the possible real, we must recognize that the right kind of hope can be a tool of change, and we must give our hope the muscle it requires in our present crisis.

Unfortunately, though, hope has seen better days. Barely more than a decade ago, Barack Obama could speak unabashedly of the “audacity of hope” in his presidential campaign, and his idea was a powerfully motivating psychological and social force in the world. And over the last fifteen years, eminent thinkers and social scientists have called for “radical hope,” “active hope,” and “intrinsic hope.” But despite these vital efforts to rejuvenate the idea, many of us have come to regard hope with disdain—as a state of mind that’s naïve and irresolute at best, delusional at worst.

Yet if we’re to survive, let alone see our children prosper in this century and beyond, we need a potently motivating principle that’s honest about the gravity of the dangers we face and about the personal responsibility each and every one of us has to face those dangers; that’s astute about the strategies we can use to overcome those dangers, given the viewpoints, values, and goals of people around us; and that’s powerful because it galvanizes our agency, our capacity to discern our most promising paths forward and choose among them. We need, in other words, the kind of hope that has motivated millions of young climate activists to sit outside parliament houses and block business-as-usual traffic in capital cities worldwide and that has galvanized communities and nations around Earth to slow the coronavirus pandemic.

In Dante’s fourteenth-century epic poem The Divine Comedy, the entrance to Hell famously carries the inscription: “Abandon all hope, ye who enter here.” The phrase has become watered down over time, almost trite. But facing a future that promises to be hell for countless people, our task in the twenty-first century is to rediscover the power of the uniquely human ability to hope—an ability to envision and strive towards a positive future that’s an alternative to whatever challenging or even unbearable present we’re living in.

I propose in the pages that follow a way of mobilizing hope’s immense psychological power, as people have done in times of great stress before and can do again. What I call commanding hope is grounded in historical and scientific knowledge of how hope works at every level—in our lives as individual human beings and in our societies too. Today, confronting challenges so large that all too often we feel unable to move, we need it more than ever.

There are no guarantees of success. The perils are real, and the chances we’ll prevail may be small. But we face a choice between denying reality, running from the crisis, or facing that crisis head on to fight for a far better future. I’ve written this book for all of us—community activists, parents and grandparents, students and teachers, business and religious leaders, farmers and builders, scientists and engineers, nurses and doctors, restaurant and shop owners and artists, politicians and voters—all of us who choose to fight.

And it’s dedicated to my children, Ben and Kate, and through them to all the children who remind us every day how to use our imaginations to tell our own story, and to see and seek the world we want.