Immanuel Wallerstein, a highly influential sociologist and radical intellectual, died at the age of eighty-eight on August 31. I never knew Wallerstein personally. I would see him at academic conferences from time to time, always accompanied by his wife, Beatrice, who would sit in the front row at his talks. Yet Wallerstein was a towering figure in my intellectual development.

Wallerstein was the last surviving member of the affectionately named “Gang of Four” — an ensemble of scholars dedicated to the study (and abolition) of global capitalism that also included Samir Amin, Andre Gunder Frank, and my doctoral advisor, Giovanni Arrighi. Giovanni and Wallerstein spent many years together at the Fernand Braudel Center — an institute founded by Wallerstein at SUNY Binghamton — and I’ve heard many, often hilarious, stories about the tight-knit community of radical scholars that blossomed there.

I’ll leave it to others to recount those tales. For me, Wallerstein leaves behind a way of thinking — an approach he called “world-systems analysis” — that, at its core, remains as compelling today as when I picked up the first volume of The Modern World-System as a young woman.

World-systems analysis crystallized in the aftermath of 1968. People across the globe took to the streets, fighting against US military aggression and for a renewal and reconfiguration of the founding principles of the Russian Revolution. The worldwide upsurge was short-lived, but its legacy was unexpectedly powerful, particularly in the academy.

By the end of the sixties, widespread dissatisfaction with dominant modes of thinking had spread among radical scholars. Indeed, world-systems analysis was just one of a number of dissident frameworks (dependency theory, international political economy, historical sociology) that emerged around that time.

For Wallerstein, world-systems analysis was as much a political protest as it was an intellectual endeavor:

World-systems analysis . . . is not a theory but a protest against neglected issues and deceptive epistemologies. It is a call for social change, indeed for “unthinking” the premises of nineteenth century social science. It is an intellectual task that is and has to be a political task as well, because the search for the true and the search for the good is but a single quest.

The year 1968 was key, but Wallerstein’s call for a new approach was also rooted in his own intellectual trajectory. After a stint in the army and a master’s degree from Columbia University, Wallerstein went to Africa in the early 1950s. For twenty years, he traveled the continent observing the mass movements fighting for decolonization.

Wallerstein had come from a politically conscious family and had been involved in activism back in New York City, but his research in Ghana and the Ivory Coast changed the way he saw the world. He credited his African studies “with opening my eyes to the burning political issues of the contemporary world and to the scholarly questions of how to analyze the history of the modern world-system. It was Africa that was responsible for challenging the more stultifying parts of my education.”

This intellectual awakening was solidified in a call to break with the assumptions that had held sway in the academy since the nineteenth century. In particular, Wallerstein argued against the disciplinary, and by extension methodological and epistemological, boundaries that defined and dominated the social sciences. His contention, which was not warmly accepted at the time, was that the “the three presumed arenas of collective human action — the economic, the political, and the social or sociocultural, are not autonomous arenas of social action. They do not have separate ‘logics.’”

Instead of research models that isolated various “factors,” or relied on comparisons of nation-states conceptualized as discrete data boxes following independent trajectories, Wallerstein insisted that the world economy was a single, interconnected system, connected by a shared division of labor and a single set of constraints — capitalism.

But in characterizing the modern world-economy as a capitalist world-economy, Wallerstein wasn’t advocating a top-down approach in which a fixed model or set of rules is used to describe and analyze reality. Instead, he insisted that capitalism was a historical system, with a beginning and an end. To understand it — its norms, its functions — we needed to examine its evolution over time and space.

Wallerstein urged scholars to jettison retrograde assumptions about historical stages and the inevitability of “progress,” and instead to challenge the dominant paradigms, to develop hypotheses and systemic frameworks that captured the complexity of capitalism as a historical, global system.

Wallerstein was a prolific scholar, proposing many of his own hypotheses about the nature of the capitalist world-system in dozens of books and articles. I disagree with many of these arguments. And so do others in the “Gang of Four,” the scholars at Binghamton, and the members of the Political Economy of the World System section of the American Sociological Association.

But Wallerstein never insisted that everyone agree with him. He relished debate.

Ultimately, a world-systems approach is not about holding to this or that hypothesis about the structures and institutions of global capitalism. It is about recognizing that we are connected across time and space — that we can’t understand what’s happening in one place in the world without situating that place within a global frame, without recognizing the global nature of modern capitalism.

In this respect, world-systems analysis remains as relevant today as ever. It gives us the tools to make sense of the gasps and sputters of our financialized economy, of the political turmoil enveloping London, Hong Kong, and so many other places, of the crumbling ideological carapace of neoliberalism.

A world-systems approach also offers a useful lesson: while the need to elect progressive leadership is urgent, the solutions to the ills of capitalism won’t be found in one country.

Nationalism is a dead-end street. Instead of closing the borders and pitting American workers against working people in other countries, we should demand programs and platforms that recognize our shared fate. National-level reforms are essential, to be sure, but lasting gains against climate change and voracious multinational corporations can only be achieved at the level of the system.

The corollary of our shared fate is the power of our shared struggle. Capital has been global for hundreds of years, but so has the struggle against capitalism, albeit to a much lesser degree. Today, despite age-old challenges, this struggle has newfound potential.

Wallerstein was a lifelong participant in this struggle. His bold and creative scholarship was a political protest against the intellectual status quo. As we will strive to build something better, we’ll remember him — and we’ll use the tools he left us.