The Scientific Marx: Falsifiability and Adhocness

By Daniel Little

Karl Popper argues that Marxist theory is an endlessly flexible instrument that can be brought to "account" for every imaginable social state of affairs. Since Marx is prepared to modify his theory in the face of falsifying empirical evidence, the theory is irrefutable and therefore unscientific. [1]

Popper's argument depends on his falsifiability criterion for distinguishing between science and nonscience.

A theory which is not refutable by any conceivable event is non‑scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice. [2]


This criterion is then used to fault Marx's scientific practice (in particular, his readiness to appeal to "countervailing tendencies"):

The Marxist theory of history, in spite of the serious efforts of some of its founders and followers, ultimately adopted this soothsaying [conventionalist] practice. In some of its earlier formulations . . . their predictions were testable, and in fact falsified. Yet instead of accepting the refutations the followers of Marx re‑interpreted both the theory and the evidence in order to make them agree. In this way they rescued the theory from refutation; but they did so at the price of adopting a device which made it irrefutable. They thus gave a "conventionalist twist" to the theory; and by this strategem they destroyed its much advertised claim to scientific status. [3]

In terms of a simple example, Popper's argument may be formulated as follows: Marx's theory of surplus value is initially an empirically significant hypothesis. One of its consequences is that rates of profit are unequal in different industries (because of unequal capital‑labor ratios). This is an empirical consequence known to be false; therefore the theory is false. If Marx is unwilling to accept this refutation, preferring instead to refer to other factors that interfere with the operation of the mechanisms specified by the theory, he can do so, but at a cost: he deprives the theory of its empirical content and its scientific standing. Given that Marx routinely suggests modifications of his theory in such circumstances, Popper concludes, his theory of capitalism is unscientific and devoid of empirical content.

Preliminary Issues Concerning Falsification

Before addressing the substance of Popper's argument, it must be noted that many of his "falsifying circumstances" miss the mark because they fall outside the scope of Marx's scientific analysis altogether. Throughout this work I have held that it is necessary to distinguish sharply between Marx's scientific treatment of the capitalist mode of production and other views he offers within his theory of historical materialism. Chapter 1 showed that the scope of the former is limited to an analysis of the logic of the economic structure of capitalism and that it is not committed to broader theses concerning capitalist society at large (e.g., the theories of politics or ideology associated with historical materialism). Marx certainly has strong opinions about the future development of capitalism, and he has a good deal to say about ideology and politics. But none of these areas is included in the core of his science; his science is strictly limited to a structural and dynamic analysis of capitalism. Once we draw this line of demarcation, however, we find that most of the facts Popper believes falsify Marx's analysis are actually irrelevant.

Let us consider one example more fully. Popper claims that the occurrence [178/179] of revolution in Russia and its nonoccurrence in Great Britain falsify Marx's systerm. [4] Do these considerations count as potential falsifications of Marx's theory? My view is that they do not. First, nothing in Capital commits Marx to any position whatsoever on the issue of the possibility of revolution in Russia. The nonindustrial, semifeudal Russia of the nineteenth-century was a radically different social formation from England and fell outside the domain of Marx's scientific investigation altogether. The occurrence of revolution there is irrelevant to the truth of his theory in Capital. Marx expressly adopts this position in his correspondence with the editorial board of a Russian periodical. There he is concerned to discourage the application of the argument advanced in Capital to the circumstances found in late nineteenth‑century Russia: "The chapter on primitive accumulation does not claim to do more than trace the path by which, in Western Europe, the capitalist economic system emerged from the womb of the feudal economic system. . . . [My critic] insists on transforming my historical sketch of the genesis of capitalism in Western Europe into an historico‑philosophic theory of the general path of development prescribed by fate to all nations, whatever the historical circumstances in which they find themselves. . . . By studying each of these forms of evolution separately and then comparing them one can easily find the clue to this phenomenon, but one will never arrive there by using as one's master key a general historico‑philosophical theory, the supreme virtue of which consists in being supra‑historical" (Correspondence, pp. 291‑93).

Is Capital at least committed to the occurrence of socialist revolution in industrialized Europe? It is not. Marx certainly believes that socialist revolution is inevitable in industrialized Europe and that Capital supports that belief. Nonetheless this conviction is only a very distant and conditional implication of his theory of capitalism. The more immediate consequences of his theory concern the developmental tendencies of capitalism: changes in property relations and in the techniques of production, concentration and centralization of industrial production, the creation of an industrial reserve army, the recurrence of economic crises, and so on. These are Marx's real "theorems." On the basis of these conclusions Marx offers an argument late in Capital to the effect that these tendencies spell the eventual ruin of the capitalist mode of production. That argument, however, cannot be considered a part of the scientific system of Capital. It is Marx's somewhat speculative projection of the substantive consequences of his theoretical system rather than a consequence of that system itself. Therefore the failure of revolution in Western Europe undermines only chapter 32 of Capital, "The Historical Tendency of Capitalist Accumulation," not the argument of the work as a whole. [5]

Thus this example fails to falsify Marx's system because it describes matters beyond the scope of Marx's scientific analysis. Moreover it is fairly typical of' Popper's chief "falsifications" of Marx's system. Consequently his charge against [179/180] Marx is weak on its own terms: It fails to offer circumstances that are related to Marx's scientific work in such a way that they could count as falsifiers.

This conclusion does not resolve the issue, however, since we can easily repair Popper's case. In the previous chapter we found that Marx's system is committed to some long‑range predictions: the falling rate of profit, the intensification of crisis, the "immiseration of labor," and the creation of an industrial reserve army. Marx's response to anomalies of these sorts is to appeal to competing factors that interfere with the basic theoretical mechanisms. Thus Popper's objection can be reformulated in terms of these examples, since none has been unequivocally borne out without need of some qualification. Is Marx's introduction of "countervailing tendencies" to account for certain failures of prediction a "conventionalist twist" that makes the analysis unfalsifiable altogether?

Marx's Use of Countervailing Tendencies

Popper's charge of unfalsifiability finds its strongest ground in Marx's use of "countervailing tendencies." (A countervailing tendency is a previously unknown factor that is hypothesized in order to account for discrepancies between theoretical expectations and observed fact.) Consider this statement of Popper's charge:

Experience shows that Marx's prophecies were false. But experience can always be explained away. And, indeed, Marx himself, and Engels, began with the elaboration of an auxiliary hypothesis designed to explain why the law of increasing misery does not work as they expected it to do. According to this hypothesis, the tendency toward a falling rate of profit . . . is counteracted by the effects of colonial exploitation. [6]

Appeal to countervailing tendencies is a central part of Marx's notion of a "law of tendency," that builds in the possibility of influences that offset the basic law. However, Popper's falsifiability thesis entails that appeal to such tendencies is itself a conventionalist twist that deprives the construction of empirical content. So let us address this issue directly: Is it irrational to appeal to countervailing tendencies to account for discrepancies between a theoretical analysis of capitalism and its observed characteristics?

We may begin with an example. In volume III of Capital Marx confronts an important theoretical problem in political economy: how to account for the falling rate of profit in British industries at midnineteenth‑century. Marx explains this tendency on the basis of his theory of surplus value. Profits are equal to surplus labor and therefore proportional to the amount of labor employed. As capitalists introduce more productive techniques to improve profitability, they normally cause the capital‑labor ratio to rise. The rate of profit, however, is equal to the ratio of the surplus to total capital employed (wages and machinery), [180/181] and as wages come to be a smaller share of the total capital, the rate of profit tends to decline. Consequently, Marx's theory of surplus value entails the law of the falling rate of profit (Capital III, pp. 317‑38). Given the details of the theoretical argument, however, one would expect the rate of profit to fall much more rapidly and constantly than it is observed to do. Whereas orthodox political economy is embarrassed by the mere fact of the fall in the rate of profit, Marx is embarrassed by its relatively slow rate of fall. [7]

Marx's response to this anomaly is to maintain that only a "law of tendency" has been discovered, that may be offset by other factors not yet represented; he then tries to discover the factors that might interfere with the mechanisms specified by the theory of surplus value. "If we consider the enormous development in the productive powers of social labour over the last thirty years alone, compared with all earlier periods. . . . then instead of the problem of explaining the fall in the profit rate, we have the opposite problem of explaining why this fall is not greater or faster. Counteracting influences must be at work, checking and cancelling the effect of the general law and giving it simply the character of a tendency, which is why we have described the fall in the general rate of profit as a tendential fall" (Capital III, p. 339).

The factors Marx cites as countervailing tendencies are unobjectionable: He observes that employers have a constant incentive to increase the intensity of the labor process, thereby balancing the decline in the rate of profit; similarly capitalists are induced to depress the wage below the value of labor power; third, capitalists can offset the decline by finding foreign markets on which commodities may be sold above their value (and labor employed below its value); and so forth (Capital III, pp. 339‑48). All these factors have obvious effects on the fundamental mechanisms of the labor theory of value, and they plainly serve to balance the tendency created by the theoretical mechanisms Marx cites. We may readily see, moreover, the social mechanisms by which they emerge: Capitalists, as they are caught in a situation of generally falling profits, will do what they can to minimize their costs and increase productivity. Introducing these factors into the analysis at a higher level, moreover, seems to be unobjectionable and not a reduction of the empirical content of the theory, since the end result is an increase in the theory's realism.

Popper's attack on countervailing tendencies, however, derives from the following consideration: Given that it is always possible to save a theory from false consequences by referring to interfering factors not accounted for in the theory, does the appeal to such factors not reduce the empirical commitment of the theory? And if the scientist is prepared to make some such appeal in every anomalous case, does he or she not relinquish claim to having provided an empirically significant hypothesis? Is it not reasonable in such a case to conclude that the theory is unfalsifiable by stipulation, and therefore devoid of empirical content? [181/182] In other words, is Popper not right in describing recourse to countervailing tendencies as the "conventionalist twist," that establishes the truth of the theory by stipulation?

This conclusion would be justified only if it were impossible to impose limits on the appeal to these tendencies—only, that is, if it were impossible to show how to distinguish between ad hoc and progressive modifications of the theory. And it presupposes that the criteria of scientific rationality attach to formal theories rather than to programs of research. In order to evaluate these charges, however, it will be necessary to consider the issues of anomaly and rational theory change in greater detail.

Anomaly and Theory Change

Popper's falsifiability thesis arises in response to the general problem of anomaly in science. Anomalies—facts or discoveries that appear inconsistent with accepted theory—are found everywhere in the history of science, since scientific inquiry is inherently fallible. If a theory implies some sentence S and S is false, it follows that the theory must be false as well. In such a case the scientist is faced with a range of choices. He or she can reject the theory as a whole; reject some portion of the theory in order to avoid the conclusion S; modify the theory to avoid the conclusion S; or introduce some additional assumption to show how the theory is consistent with "not S." A strict falsificationist would presumably require that we disavow the theory, but this response is both insensitive to actual scientific practice and implausible as a principle of methodology.

When faced with anomaly, the scientist must choose whether to abandon the theory altogether or modify it to make it consistent with the contrary observations. If the theory has a wide range of supporting evidence (aside from the contrary experience), there is a powerful incentive in favor of salvaging the theory, that is, of supplementing it with some further principle restricting the application of its laws, or modifying the laws themselves, to reconcile theory with experience. Ideally the scientist ought to proceed by attempting to locate the source of error in the original theory. Theory modification in the face of contrary evidence should result in a more realistic description of the world, either through the correction of false theoretical principles or through the description of further factors at work that were hitherto unrecognized.

It is possible, however, to modify a theory in ways that do not reflect any additional insight into the real nature of the phenomena in question, but are rather merely mechanical modifications of the theory made to bring it into line with the contrary evidence. Such modifications are common in the history of science; Hempel cites the example of phlogiston theorists under attack by Lavoisier. After Lavoisier's discovery that metals weighed more after combustion than prior (thereby apparently falsifying phlogiston theory), some proponents [182/183] of that hypothesis modified their concept of phlogiston by assuming that it possessed negative weight. This alteration reconciled the phlogiston theory with Lavoisier's evidence; nevertheless it seems on fairly intuitive grounds to be an illegitimate modification. It is “introduced ad hoc—i.e., for the sole purpose of saving a hypothesis seriously threatened by adverse evidence; it would not be called for by other findings, and, roughly speaking, it leads to no additional test implications.” [8]

The problem of avoiding adhocness by devising a set of methodological standards suitable for governing the modification of hypotheses in light of contrary evidence is a substantial one. As Hempel observes, the clearest judgments of adhocness are made with the benefit of hindsight; what may have been a rational modification given current beliefs is with the benefit of later knowledge a transparent case of ad hoc modification. However, we may advance a rough set of guidelines for the introduction of modifications: "Is the hypothesis proposed just for the purpose of saving some current conception against adverse evidence, or does it also account for other phenomena, does it yield further significant test implications?" [9] Does it contribute to a theory that affords simple explanations of a wide range of phenomena? Does it appear to represent an increased knowledge of the real mechanisms that underlie observable phenomena? Does it merely repeat the evidence already available, or is it amenable to independent tests?' [10] These considerations fall far short of a definition of adhocness, and recent work in the philosophy of science has substantially extended these ideas by introducing the notion of a research program. [11]

Postpositivist Treatments of Anomaly

Postpositivist philosophy of science has directed much of its efforts to formulating more adequate standards for modifying theory in the light of anomaly. Its chief insights have resulted from a shift of attention from the level of finished theories to the level of the research program, that is, from the formal laws and principles of a theory to the more encompassing set of presuppositions, methodological commitments, and research interests that guide scientists in the conduct of research and theory formation. The central focus of neopositivist theory of science was the scientific theory, conceived ideally as a formal system of axioms and deductive consequences. Neopositivists distinguished between tile context of discovery and that of justification, and they argued that only the falter fell within the scope of rational control. This meant that only finished theories could be rationally evaluated, whereas the conduct of research was conceived of as an exercise of pure, unregulated imagination. [12] From this judgment followed fal sifi cation i sm, verificationism, and various forms of confirmation theory.

The "new" philosophy of' science focuses on the "context of discovery"—the assumptions and research goals that guide scientists in their research. Philosophers of science in this area reject the idea that the conduct of research [183/184] is an unstructured, nonrational process, and they have tried to formulate a theory of the rules that distinguish good scientific research from bad. From this starting point, the "research program" becomes the central interest. [13]

What is a research program? It is the framework of assumptions, experimental procedures, explanatory paradigms. and theoretical principles that guide the conduct of research. Lakatos has provided an especially clear formulation of the concept. [14] First, he argues that any research program possesses a "hard core" of theoretical principles that constitute its central insight into its subject matter. This core is taken as fixed; the "negative heuristic" of the program forbids the scientist from interpreting anomalous results as falsifying this core. Instead, the scientist is directed to construct a "protective belt" of auxiliary assumptions intended to secure the correctness of the theoretical principles at the core, and scientific research becomes an effort to modify or replace the assumptions included in the belt so as to make the core consistent with experimental results. Finally, the research program includes what Lakatos calls a "positive heuristic": a set of principles and assumptions that provide guidance in extending and developing the belt. This conception of scientific inquiry could be summarized in the form of a slogan: Defend and extend! Built into the view is a rejection of falsificationism, for, far from seeking to refute the central theoretical principles, the scientist is directed to defend and extend them as forcefully as possible.

With this fundamentally different starting point, the new philosophers of science have posed a different question for themselves. Rather than the positivists' question—What is the criterion of an empirically adequate theory?—they have asked, What are the features that distinguish a rational and progressive program of research from its contrary? The problem of theory adequacy does not disappear, but it becomes a subordinate concern. This broader approach to empirical rationality lays the emphasis on the degree to which the commitments of the research program successfully direct research productively and suggest empirically adequate theories—rather than on the narrower question of the criterion of empirical adequacy of theories. On this view, empirical rationality is a feature of the program of research rather than the finished theory; theories are tools for understanding empirical phenomena created by the scientist within the context of a framework of methodological and substantive assumptions.

From this research‑oriented point of view, falsificationism is an unsound principle of theory choice, since it is an extreme principle that requires the rejection of any theory with false consequences. A more conservative strategy is required, one that allows the scientist to preserve the old theory at minimum cost. On this view, it is generally a reasonable methodological principle to try to formulate a hypothesis that would account for the truth of a theory and the falsehood of one of its consequences S—either by supposing S is really true (i.e., experimental error) or by modifying the theory or by positing some unobserved factor that, together with the theory, predicts "not S." (Consider, for example, [184/185] the anomalies arising in the Newtonian description of the planetary orbits that led to the subsequent positing of Uranus.) It is reasonable, that is, to take as a research strategy the maxim of least harm: to try to produce a reconciliation of theory and observation that requires the least change in the theory. And the general success of scientific theory formation guided by this maxim vindicates the strategy.

The problem with the principle of least harm is that it allows us to stave off rejection of the theory indefinitely; it potentially makes the theory irrefutable. Once we widen our vision from theories to research programs, however, we find that the key problem is not how to keep a theory falsifiable but rather how to impose a set of rational constraints on the principle of least harm: how to avoid ad hoc modifications of theory that fail to advance the theory's empirical power and explanatory adequacy.

Lakatos has discussed this question in detail. His account is not altogether adequate, but it gives an indication of the sort of criterion of adequacy that seems to have some promise of success. On his view, the problem is how to define the notion of a "progressive problem shift," that is, a modification of theory in light of conflicting experience that improves the empirical adequacy of the theory. Lakatos gives a twofold criterion of progressiveness. A modification of theory is theoretically progressive if the modification has some excess empirical content over its predecessor, and it is empirically progressive if some of this content is corroborated. If the change is not progressive in these senses, the research tradition is in a state of degeneration and ought to be replaced. [15]

This conception of a progressive research tradition may be amplified into a more specific criterion of rational adherence to an empirical theory in the face of anomaly. First, the theory in question must have achieved some empirical success. That is, it must produce empirically adequate explanations of phenomena in areas other than those affected by anomaly; otherwise it would be irrational to remain committed to the theory. And second, the modifications of the theory must themselves be, at least potentially, empirically significant. (1) They must give rise to other consequences besides the range of phenomena they were introduced to explain, and (2) they must be amenable to further investigation. If these conditions obtain, and if independent justification is produced for the new factors, both they and the earlier theory are vindicated.

Application of These Results to Marx's Research Program

Marx's research program satisfies these standards of progressiveness and therefore is an empirically defensible effort in social science. First, the program defines a "hard core" of theoretical principles that appear to constitute an important insight into the workings of the capitalist economy, and as well as a fairly precise tool for further investigation. This core includes the theory of the class nature of capilalism. Marx's account of the defining features of the capitalist economic [185/186] structure, his analysis of crisis, and so forth. Furthermore this core has had some notable empirical successes. So the research program possesses the basic empirical credentials we found necessary. [16]

Second, the program has been fertile in directing research. Within the area of social science loosely inspired by the Marxian theory of capitalism are to be found indisputably fruitful examples of research. Marxist economic theory has included the contributions of Paul Sweezy, Maurice Dobb, Ernest Mandel, and Michio Morishima; Marxist historiography has produced Eugene Genovese, E. P. Thompson, Albert Soboul, and others; the Marxist theory of politics has given rise to Ralph Miliband, Nicos Poulantzas, and Theda Skocpol; and Marxist sociology has inspired Tom Bottomore and Anthony Giddens, to name only two. This variety of productive efforts indicates that the program has provided the sort of heuristic value expected of research programs.

And finally, the modifications of the theory, and the appeals to countervailing tendencies (the development of the protective belt), that subsequent Marxist social science has witnessed seem by and large to have the progressive properties that Lakatos requires. They have enhanced the empirical power and scope of the theory, and they have been amenable (by and large) to further empirical research (contrary to Popper's assertion that they are merely conventionalist strategies). They have led to a more precise formulation of the economic model; a more detailed model of class stratification; a more finely drawn analysis of the influence of the financial system on the dynamic of capitalist accumulation; and a more precise analysis of the influence of economic structure on the system of education. [17] Marx's program thus gives every appearance of having been both theoretically and empirically progressive, in Lakatos's terms, and it seems to have been fruitful in just the way a successful program of research ought to be.

On the preceding interpretation of theory change in science, then, appeal to countervailing tendencies is neither irrational nor uncontrollable; it is rational to try to save the theory, and we can specify relatively clear criteria of success and failure in the attempt. Appeal to such factors can in principle constitute a progressive research strategy and does not prima facie affect the empirical content of the theory. It may well transpire that the theory is not progressing, and if this is the case, it ultimately must be rejected. But merely to look for ways of accommodating recalcitrant data is not by itself irrational. This is all we need to conclude that the appeal to countervailing tendencies does not by itself reduce the empirical content of the theory. Popper's charge that Marxist social theory is devoid of empirical content is therefore unsupported. Marx's analysis may eventually be shown to be false. Its falsity, however, can be shown only by the long‑term failure of detailed research launched in its name and the success of research that contradicts it; it cannot be evaluated in advance of sustained social inquiry.


1. The falsifiability thesis is developed throughout Popper's works. For a simple statement see Conjectures and Refutations: The Growth of Scientific Knowledge (New York: Basic, 1965), pp. 36‑37, and The Logic of Scientific Discovery (New York: Harper, 1968), pp. 78‑92. For Popper's application of falsifiability to Marx, see Conjectures and Refutations, p. 37, and The Open Society and Its Enemies, vol. 2 (Princeton: Princeton University Press, 1971), pp. 187‑89. [225/226]

2. Karl Popper, Conjectures and Refutations, p. 36.

3. Ibid., p. 32.

4. Karl Popper, Open Society and Its Enemies, vol. 2. pp. 105, 109, 144.

5. Indeed, Popper seems to recognize this point when he writes that Marx's argument for the inevitability of socialism involves three stages, and that "Capital elaborates only . . . the 'first step' of this argument." The Open Society and Its Enemies, p. 136.

6. Ibid., p. 187.

7. Ernest Mandel summarizes some twentieth‑century data on the behavior of the rate of profit in Marxist Economic Theory, vol. I (New York: Monthly Review, 1970), pp. 166‑170.

8. Carl Hempel, Philosophy of Natural Science (Englewood Cliffs, N.J.: Prentice‑Hall, 1966), pp. 28‑30.

9. Ibid., p. 30.

10. Popper, Conjectures and Refutations, p. 288.

11. Larry Laudan's Progress and Its Problems (Berkeley: University of California Press, 1977) provides a good critical summary of the views of philosophers of science who give pride of place to the idea of a research program or paradigm.

12. "The initial stage, the act of conceiving or inventing a theory, seems to me neither to call for logical analysis nor to be susceptible to it. The question how it happens that a new idea occurs to a man . . . may be of great interest to empirical psychology; but it is irrelevant to the logical analysis of scientific knowledge. . . . Accordingly I shall distinguish sharply between the process of conceiving a new idea, and the methods and results of examining it logically." Popper, The Logic of Scientific Discovery, p. 31.

13. See Imre Lakatos, "Falsification and the Methodology of Scientific Research Programmes," in Lakatos and Musgrave, eds., Criticism and the Growth of Knowledge (Cambridge: Cambridge University Press, 1970), pp. 91‑195, for a definitive statement of the notion of a research program. Larry Laudan's Progress and Its Problems also discusses and extends the concept of a research program (pp. 70‑120).

14. Lakatos, "Falsification and Methodology," pp. 132‑38. Although I believe that Lakatos's criterion of progressiveness shows Marx's social theory to be genuinely scientific, it must be noted that Lakatos does not ("Methodology," p. 92 and elsewhere).

15. Ibid., pp. 116‑22.

16. Ernest Mandel marshalls some of the empirical support available for Marx's economic analysis in his introduction to Capital II, pp. 22‑24 and 80‑86. His treatment is of special interest because it directly responds to Popper's charge of unfalsifiability.

17. Consider Michio Morishima, Marx's Economics (Cambridge: Cambridge University Press, 1973); J. H. Westergaard, Class in A Capitalist Society (New York: Basic, 1976); James O'Connor, The Fiscal Crisis of the State (New York: St. Martin's, 1973), and Samuel Bowles and Herbert Gintis, Schooling in Capitalist America (New York: Basic, 1976).

SOURCE: Little, Daniel. The Scientific Marx. Minneapolis: University of Minnesota Press, 1986. This extract, "Falsifiability and Adhocness" (pp. 177-186, with endnotes, pp. 225-226), is a section of chapter 7, "Falsifiability and Idealism" (pp. 177-195).

Vienna Circle, Karl Popper, Frankfurt School, Marxism, McCarthyism & American Philosophy: Selected Bibliography

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