These historians, who were generally Progressives in politics, emphasized the importance of class conflict and the power of economic interests in their studies, revealing the influence of Karl Marx (1818–83). Marx and Friedrich Engels (1820–95) worked together in almost total isolation, and when Marx died it would have been difficult for a casual observer not to conclude that his ideas would disappear with him. By 1900, however, Marxism constituted the greatest challenge to the idealist tradition.

Despite the influence of philosophy, sociology, and economics, Marx’s thought was profoundly historical. Hegel had taught him that history was constant change, produced by oppositions, reconciliations, and more oppositions. Acknowledging (in a way) this debt, Marx remarked that he found Hegel standing on his head and turned him right side up again. By this he meant that Hegel had mistaken the real motor of history: it was not the conflict of ideas but the conflict of social classes. Marx admitted, however, that this was not his own discovery; the “bourgeois” historians, such as Vico, had anticipated him. What Marx brought to the idea of class struggle was a conception of how it had developed and how it must eventually turn out.

Marx’s understanding of class struggle was influenced by the work of the English economist David Ricardo (1772–1823), who had developed a model of how “perfect” markets work in a capitalist mode of production. Ricardo had made the conflicting interests of landlords, employers, and workers the centre of his picture of the economy. He argued that, because of Malthusian population dynamics, the wages of workers would always be held at or near subsistence levels. Marx extended the analysis by taking into account increases in population and in the productive powers of the economy. He correctly predicted—at a time when there were very few companies that employed more than 50 workers—that the size of capitalist enterprises would inexorably increase until giant corporations dominated the economy. Equally correctly, he predicted that the proportion of the labour force engaged in agriculture (over half in parts of Europe) and the number of small business owners would sharply decline, so that proletarians—those who had nothing to sell but their labour—would become the overwhelming majority of the population. Marx was less certain about the political consequences of these changes; by the end of his life he thought that capitalism might be brought to an end without violent revolution in some countries (the United States among them), and he saw that not all societies would pass through exactly the same sequence of changes. But he never lost his confidence that the system of private ownership of the means of production, in which enormous quantities of wealth accumulated in fewer and fewer hands, would inevitably be replaced by socialism.

None of this is history, properly speaking. The appeal of Marxism, for some historians, has been the rigour of this economic argument, which promises an eventual system based on moral precepts more appealing than “greed is good”; they also have been attracted to its suggestive implications for a unified approach to history. These are implications only, however. Marxist historiography, as a contemporary Marxist once said, is still “under construction.” Marx’s own historical writings are far from a mechanical application of his system. In his brilliant Der 18te Brumaire des Louis Napoleon (1852; The Eighteenth Brumaire of Louis Bonaparte), several classes, not just two, played important roles, and the political skill of Napoleon III is acknowledged—albeit grudgingly—as significant. Although some Marxist historians may still maintain a residual allegiance to the notion that ideas are a mere “superstructural” reflection of the material “base,” the way this relationship is supposed to work has never been satisfactorily demonstrated, and this aspect of Marxism has largely been laid aside.

In recent times the idea has gained currency that Marxism has been “refuted by history.” No successful revolution has broken out in any advanced capitalist country, and the collapse of the Soviet Union and the failure of the regimes in eastern Europe that called themselves Marxist has been taken as the conclusive demonstration that Marx was wrong. But “history” refutes nobody; only historians can do that, and other historians, looking at different evidence or reinterpreting the same, can in turn refute them. A more well-grounded objection might be that there is no way to refute Marx, because his predictions are insufficiently precise; for example, he wrote that no mode of production gives way to its successor before it has exhausted all of its possibilities. The history of historiography suggests, however, that no grand scheme, whether of Augustine, Hegel, or Marx, can be “disconfirmed” by empirical evidence. They are different interpretations of history, more or less persuasive as one judges them on what are essentially aesthetic or moral grounds. The option to refuse to interpret in such a mode is of course always open.