By the later 17th century, these markers were appearing in works by a great variety of political thinkers from Locke to Montesquieu. They also inspired political actors, especially in the American colonies. When one reads the writings of American founders such as Madison and Adams, for example, one finds frequent homages to Polybius in particular and allusions to ancient Greek history in general. This prompts Edelstein to argue that the American Revolution was not truly a revolution in the modern sense, since it was not an attempt at political novelty but a reprisal of classical ideas. The architects of the American Constitution were (in his words) “the last of the Polybians.”

In arguing this case, Edelstein seeks to overturn the work of the historian Gordon Wood, who characterized the drafting of the American Constitution in 1787 as “the end of classical politics.” Edelstein believes that this is mistaken. By ascribing to the American founders the modern idea of revolution as a rupture, Edelstein thinks that we have fundamentally misread their intentions. “They did not hope for or imagine a future society that differed dramatically from the present,” he writes. “Some may have dreamed of a time when slavery was abolished, but none believed that less offensive forms of inequality would disappear. Rather than transforming their world, they wished above all to preserve the state.” Like the English during the Glorious Revolution of 1688, when they welcomed William of Orange to the throne, the revolutionaries in the American colonies wished for restoration, not social progress or dramatic change. For them, the word revolution did not signify a break from the past; it meant a return to what was there before.

With this argument, Edelstein has placed himself squarely on one side of an ongoing debate over the meaning of the American Revolution. Was it a revolution in the full sense of the word, or was it something more benign, less riven by conflicts of wealth or class? Edelstein gives little credence to the “economic interpretation of the American Constitution” first presented more than a century ago by the progressive historian Charles Beard, who argued that the Constitution reflected the rival class interests of two factions, mercantile and landed. (The American Revolution, Beard concluded, was therefore not really a revolution at all; it was a counterrevolution that secured the propertied interests of the founding fathers.) Nor does Edelstein devote much space to a discussion of religious factors. Against intellectual historians such as Karl Löwith, who once argued for the Christian and distinctively eschatological background to the modern idea of progress, Edelstein denies that the Christian longing for a millennium played a motivational role in 1776. For Edelstein, the American Revolution was neither economic nor religious; it was animated first and foremost by the Polybian idea of a mixed government that was thought to provide a bulwark against extremism or seismic political change.

Yet if the American Revolution was not a revolution in the modern sense, then what was? Here Edelstein turns to the turbulent world of the French Revolution and its modern aftermath. It was during the French Revolution, he argues, that cyclical time yielded to time as progress, and the salutary ideal of mixed government yielded to the muscular ideal of a final revolution that cleared the way for tyranny. As the book follows this narrative, the reader can discern a subtle shift in tone. In its earlier sections, Edelstein writes in a style of curiosity: The votaries of Polybius appear in a gentle light. But when he shifts his focus to the French Revolution, admiration gives way to judgment. Perhaps this should not surprise us, since Edelstein now finds himself on the terrain that he knows best. Unfortunately, his distaste for the revolutionaries in France often moves him to polemic.

Of course, this shift in tone is hardly unusual, since few topics arouse greater controversy among historians than the French Revolution. At least since Tocque­ville and Michelet, historians have debated the question of whether the bloody events of the Terror marked the culmination of the revolution or its betrayal. For Tocqueville, an aristocrat by origin but a liberal in political disposition, the French Revolution could only be judged from the standpoint of its ironic denouement: The Jacobins may have wished to abolish monarchy, but they succeeded only by centralizing a state that then served as an instrument of autocracy. Opposing such arguments were the historians and political theorists (many of them—though not all of them—Marxists) who wished to defend the idea of revolution and who argued that the 1789 revolution does not stand under the sign of the guillotine: One could be for the French Revolution but against the Terror.

In the later 20th century, some historians sought to challenge the Marxist interpretation and appealed for assistance to the liberal interpretation associated with Tocqueville. Among the most consequential contributors to this debate was François Furet, who argued that the Terror could not be dismissed as an aberration; it was an event intrinsic to the revolution itself. According to Furet, the Marxists were also mistaken in their economic analysis, since the revolution had little to do with class conflict; it was essentially a contest over competing ideologies—one egalitarian, the other authoritarian.

Edelstein’s study of the idea of revolution reads something like an homage to Furet. Like his liberal predecessor, Edelstein seems to harbor a strong distaste for political extremisms of any sort, and he also argues, like Furet, that the French Revolution opened the way to even worse excesses to come. Edelstein, however, puts a distinctive stamp on the argument. To understand what is so dangerous in the modern idea of revolution, he insists, we must appreciate how much it draws inspiration from the Enlightenment philosophers of history who developed the modern concept of progress. This shift in the concept of time radically changed our concept of revolution, for if, in the past, history was conceived as pursuing a cycle among political regimes, with the French Revolution history became a forward line. Politics was no longer a Polybian contest among citizens in a pluralistic order; it became instead a mortal struggle over the meaning of revolution itself, and all opponents or moderates became counterrevolutionaries, enemies of the future who must be either subdued or killed.

Edelstein seems to believe that this new kind of revolutionary reasoning flows from the modern idea of progress itself. “Revolutions that embrace a modern vision of history,” he contends, are “highly susceptible to the kinds of political terror that marked so many revolutions from 1789 onward.” It is here that Edelstein seems to resurrect arguments from Hannah Arendt and various Cold War liberals, who argued that a path leads directly from the 18th-century Terror to 20th-century totalitarianism.

In fact, when reading The Revolution to Come, one can often hear the echoes of On Revolution, Arendt’s 1963 comparative study on the differences between the revolutions in America and France. Like Edelstein, Arendt insisted on a sharp contrast: Where the Jacobins were bent on a thoroughgoing makeover of “the social,” the American founders were satisfied with the more moderate and pragmatic task of reshaping “the political.” Much in the spirit of Arendt, Edelstein argues that the revolutionaries led France “from democracy to dictatorship” and thereby furnished a general model for revolution in the centuries to come.

But Edelstein gives this argument a singular spin. The idea of progress, he contends, encouraged a kind of determinism in both theory and practice, since it gave revolutionaries the highest claim on the unfolding of history, as if its movements were like those of an organism: metabolic, not political.

This argument is no doubt fascinating. But to accept it demands a rather teleological reading of intellectual history in which bad ideas prepare the way for future horrors. By treating ideas as “genetic markers,” Edelstein does not mean to adopt a method of determinism. But it is hard to escape the impression that he thinks of ideas as vehicles for a bacillus that will infect its host. The irony, of course, is that this way of understanding history looks suspiciously like an inversion of the philosophies of history that Edelstein finds so objectionable: Progress has become regress, good ideas losing out to bad.

No one should fault Edelstein for trying to paint on a broad canvas. But when he turns to the post-revolutionary period, one can sense his impatience. The shapes of history grow impressionistic, and details are drafted for the purposes of polemic. Edelstein may find little to admire in European liberals (since they upheld strong property restrictions and nourished dreams of empire), but he has even less sympathy for Marxists and other exponents of socialist revolution, all of whom, in his eyes, are guilty of thirsting for dictatorship. In fact, Marxism seems to illustrate everything that he finds wrong in the modern idea of revolution. For Edelstein, the Marxist idea of a “dictatorship of the proletariat” becomes only one instance of a general delusion that has afflicted revolutionary movements throughout the modern era. “The choice of dictatorship” was not predetermined, he admits: It was a “temporal shortcut” that only emerged as a likely option once the revolutionaries came to believe in the possibility of a “perfected future.”

This belief in a golden age to come helped inspire the genre of utopian novels that projected our collective fantasies into an idealized time that always lay just beyond our reach. Edelstein adds, in a rather brilliant aside, that such ideas capitalized on the “future perfect,” the grammatical tense that offered the soothing thought that someday all will have been justified. Hiding in the idea of utopia, however, was the dangerous prospect that struggles for the future might be enlisted to justify violence in the present, while those who did not share the revolutionaries’ political convictions were to be condemned as counterrevolutionary. “By opening up the future as a space to be colonized by a just society,” Edelstein writes, “the modern doctrinaires of progress encouraged their followers to value the world to come so highly that they were willing to accept the temporary suspension of democratic beliefs.”

Edelstein wishes us to understand the idea of “colonization” as more than just a metaphor. Colonizing the future in the political sense would be, in his eyes, analogous to colonizing other lands. But in a book that is otherwise overflowing with insight, this claim strikes me as tendentious. The equation, though no doubt ingenious, obscures an obvious difference: In the imperial imagination, the unfortunate souls who fall prey to the mission civilisatrice are expected to feel only gratitude, since they are being lifted up—by force, if necessary—to a higher plateau of historical development. But the language of empire was never more than a mask: It was used to conceal and to justify the most brutal practices of expansion, exploitation, and compulsion.

The idea of progress, however, cannot be so easily dismissed. Whenever human beings wrest themselves free of inaction and seek to change their fate, they must believe that their conduct might just possibly bring about an improvement in their lives. Most revolutionaries cleave zealously to this belief—but then, so too do most other political agents. In fact, the idea of progress in this sense animates most human action, and it can be abandoned only in the most extreme circumstances, when our behavior seems altogether without actual effect and we yield to fatalism.

Like many other recent critics of progress, Edelstein seems to believe that the idea itself is irredeemably tainted because it has too often served as a warrant for imperialist atrocity. But this verdict makes little sense. If atrocity is bad, then we should strive for its elimination, and yet bringing it to an end would surely count as an improvement. Adorno once tried to compress this argument into a single aphorism: “Progress occurs where it ends.” Yes, progress is of course an ideology—but it is not only an ideology, or we could not yearn for a world better than it currently is.

This may explain why Marxists of nearly every stripe have been so reluctant to abandon the idea of progress, whatever its flaws. It is not because they wish to “colonize time,” nor is it because, as Edelstein would claim, they all adhere to the utopian vision of “permanent revolution”; it is because they see the historical future as the only theater in which it would be possible to realize our freedom.

Curiously, Edelstein devotes less energy than we might have expected to Marxist theory. In an edifying book on revolution that stretches to nearly 300 pages, only about 40 are dedicated specifically to Marx, and most of those concern his writings on French history.

I would not blame Edelstein for this choice, were it not for the fact that his attitude toward Marxism reflects a broader attitude of indifference toward methods of inquiry beyond the bounds of the historical profession. He seems to think that most social scientists do not take ideas seriously, so in pursuing a history of ideas, he concludes that he does not need to take social scientists seriously. In the introduction to his book, he writes that “much of the social scientific literature on the topic [of revolution] is not particularly relevant.” Why? Because “much of the social scientific literature” on revolution adheres to the “fundamental premise” that “political thought is mostly irrelevant.” Most social scientists apparently believe that ideas are mere epiphenomena or froth on the waves. To prove this point, Edelstein refers to Marx, who ostensibly thought that “only material considerations have an impact on political events,” while “ideas and culture are merely smoke and mirrors deployed by the ruling class to stay in power.”

One need not boast any expertise in Marxist theory to find this inaccurate. Marx was seldom so reductive, and if he truly believed that all ideas were “merely smoke and mirrors,” his own exertions in theory would have had little purpose. The slip is unfortunate, since it arouses the concern that Edelstein may be tilting at windmills. When a book is so thoughtful in other respects, one might feel inclined to excuse its flaws, and yet I fear that this hostility toward Marxism may be the symptom of a deeper problem. Edelstein has crafted a genuinely powerful narrative that illustrates what psychoanalysts would call “splitting”: It enlists historical argumentation for the purposes of a mythic contest between two ideas of revolution, one bad, one good—progress here, anacyclosis there; the French revolutionaries on one side, the American revolutionaries on the other.

Edelstein seems confident that we can immunize ourselves against the bad while embracing the good: We can be Polybians without permanence, and progressives without progress. But if we follow the implications of his book, we might conclude that it would be best to forsake our modern notions of progress altogether and turn back to the ancient idea of cyclical time. The strange conclusion of this brilliant but at times puzzling book is that we are confronted with only two options, militancy or complacency. But history is not forcing us to choose.