The transition from feudalism to capitalism spanned centuries, and although humanity does not have the luxury of waiting for a transition to socialism taking that length of time, the struggle to overcome capitalism has already spanned a century with no victory in sight. Countries as diverse as the Soviet Union, Czechoslovakia and Nicaragua fell back into capitalism, but that does not mean we have nothing to learn from a study of those revolutions.

This is history that was shaped by flesh-and-blood human beings — leaders of movements and uncounted men and women in the streets and in the workplaces motivated by a desire to create a better world. That the results of uprisings as diverse as the October Revolution, the Prague Spring and the Sandinista Revolution did not meet the revolutionaries’ expectations is a tragedy that requires explanation, but does not require us to deem those revolutionaries as failures.

The edifice of the Soviet Union was something akin to a statue undermined by water freezing inside it; it appears strong on the outside until the tipping point when the ice suddenly breaks it apart from within. The “ice” here were black marketeers; networks of people who used connections to obtain supplies for official and illegal operations; and the managers of enterprises who grabbed their operations for themselves. Soviet bureaucrats eventually began to privatize the economy for their own benefit (fulfilling a prediction made by Leon Trotsky half a century earlier); party officials, for all their desire to find a way out of crisis, lacked firm ideas and direction; and Soviet working people, discouraged by experiencing the reforms as coming at their expense and exhausted by perpetual struggle, were unable to intervene.

The Prague Spring and the Sandinista Revolution provide disparate examples. History has concentrated on the tragedy of Czechoslovakia’s political leaders, but much of the innovation of Prague Spring came at the grassroots level, where self-organized workers began to devise the beginnings of a system of social control over industry free of bureaucratic shackles. Grassroots creativity propelled forward a Spring begun by leaders of a monopoly party who believed that the full democratic and human potential of socialism had to be allowed to blossom, requiring dramatic changes. The Sandinista Revolution’s goal was a mixed economy, not the creation of a socialist system, but although that mixed economy created a new set of problems it also improved the lives of Nicaraguans. Nonetheless, the Sandinistas left economic power in the hands of the country’s capitalists, leaving them with the ability to undermine the revolution.

Thinking about the basic contours of a better world is a prerequisite to becoming effective in bringing it into being. The march forward of human history is not a gift from gods above nor presents handed us from benevolent rulers, governments, institutions or markets — it is the product of collective human struggle on the ground. Toward this end, an understanding of today and finding a path to the future is impossible without an understanding of the past: Erasing the past is erasing the future.

Pete Dolack is the author of It’s Not Over: Learning From the Socialist Experiment, which includes studies of each of these revolutions and a final chapter that looks to the future. Different nations will find different paths forward and it is impossible to apply any formula across multiple societies at differing levels of development and possessing divergent cultural traditions, so no blueprint for the future is possible. Nonetheless, with capitalism in deep crisis with no answer for working people, the time is now for us to think about the contours of a better world.