Image. Orderly chaos in flight path of ocean-foraging albatross
The case for scientific realism in the case of physics, microbiology, and chemistry is a strong one. The theories of physics, biology, and chemistry postulate unobservable entities, forces, and properties. These hypotheses are specified in a fair degree of precision. They are not individually testable, because we cannot directly observe or measure the properties of the hypothetical entities. But the theories as wholes have a great deal of predictive and descriptive power, and they permit us to explain and predict a wide range of physical phenomena. And the best explanation of the success of these theories is that they are true: that the world consists of entities and forces approximately similar to those hypothesized in physical theory. So realism is an inference to the best explanation, based on the engineering and observational successes of physics, chemistry, and biology. (In the diagram above we might hypothesize that the foraging strategies of the albatross have evolved towards a combination of random walk and orderly search pattern through a process of natural selection; this hypothesis can be empirically investigated in a variety of ways.)
If we lived in a more chaotic physical world, with a larger number of more variable forces at work, our physical theories would be greatly less successful at representing the behavior of observable physical systems, and we would have much less confidence in the idea that various snippets of our physical theories are "true" of the world. If space were more like a pudding with abrupt variations in curvature and gravitational force, and were in addition subject to a numerous other factors and forces, our confidence in the science of mechanics would be greatly undermined. We would never know even approximately where the fly ball will go.
The situation in political science and sociology is quite different from astronomy, atomic theory, and mechanics. First, there are no theories in the social sciences that have the predictive and explanatory success of the physical sciences. Second, the social world is more like the fantastic and chaotic scenario just mentioned than it is an ice rink with frictionless surfaces and predictable mechanics. The social world embodies multiple heterogeneous causal and structural influences that aggregate in contingent and surprising ways. Third, sociologists and political scientists sometimes make hypotheses about unobservable or hypothetical social entities. But these hypotheses do not assume the logical role of that played by hypotheses in the natural sciences. Hypothetical social entities may be unobservable in a fairly ordinary sense -- no one can directly observe or measure a social class. But in fact, these concepts do not depend on holistic confirmation in the way that hypotheses in the natural sciences do. Rather, it is perfectly possible to further refine our ideas about "social class", "prisoners' dilemma", or "bipolar security field" and then investigate the manifold aspects of these concepts through direct social research. Sociology and political science do not consist of unified deductive systems whose empirical success depends upon a derivation of distant observational consequences; instead, it is possible to investigate essentially every sociological or political concept through various direct methods of research and inquiry. (This ability is not unique to the social sciences. The study of animal behavior likewise admits of a variety of hypotheses at various levels that can be independently studied.)
In short, the social sciences do not possess the remarkable coherence and predictive accuracy of physics, so confidence in realism is not grounded in the high level of success of the enterprise. Sociology is not like physics.
But equally, the concepts of the social sciences are not "hypothetical constructs" that depend upon their role in a developed theoretical system for application. It is therefore possible to be piecemeal realists. Again, sociology is not like physics.
So it seems that two specific ideas follow. First, the inference to the best explanation argument for realism doesn't work at all in sociology or political science. We simply don't have the extraordinary predictive successes of a theoretical system that would constitute the ground of such an argument. Social science theories and models remain heuristic and suggestive, but rarely strongly indicative of the reality of the social factors they highlight.
But second, there is a very different kind of argument for social realism that is not available in the natural sciences: the piecemeal investigation of claims and theories about social entities, properties, and forces. If we believe that class conflict is a key factor in explaining political outcomes, we can do sociological research to further articulate what we mean by class and class conflict, and we can investigate specific social and political processes to piece together the presence or absence of these kinds of factors.
So it seems that we can justify being realists about class, field, habitus, market, coalition, ideology, organization, value system, ethnic identity, institution, and charisma, without relying at all on the hypothetico-deductive model of scientific knowledge upon which the "inference to the best explanation" argument depends. We can look at sociology and political science as loose ensembles of empirically informed theories and models of meso-level social processes and mechanisms, each of which is to a large degree independently verifiable. And this implies that social realism should be focused on mid-level social mechanisms and processes that can be identified in the domains of social phenomena that we have studied rather than sweeping concepts of social structures and entities.
This perspective converges unexpectedly with some of the thinking that Peter Manicas put forward in his book on social-science realism, A Realist Philosophy of Social Science: Explanation and Understanding. What is realism, in the natural sciences, he asks? It is not a general claim to have discovered the universal laws of everything.
Rather, more modestly, theory (at least in one of its clear senses) aims to provide an understanding of the processes which jointly produce the contingent outcomes of experience. We understand why the planets move in ellipses, why materials burn, and why salt dissolves in water (if and when it does) when we have a physical theory that provides a causal mechanism. By providing the principles detailing the nature of molecules, the atomic structure of salt and water, the principles of their action, and so on, we can understand combustion and solubility – and other chemical processes. (1)So what are the generative mechanisms in the social world? Manicas argues that these mechanisms proceed from the actions and relations of social agents:
The foregoing has also argued that persons are the dominant causal agents in society – even while, of course, they work with materials at hand. It follows, accordingly, that in the social sciences, the generative mechanisms of social outcomes are the actions of persons and no further reduction is either plausible or demanded. (75)So his most general idea about the social world is "social mechanisms as agent-generated causal mechanisms" (2).
If this is the approach we take, then our claims about what is "real" in the social realm will be more modest that some have thought. We will understand that there are real social processes, mechanisms, and powers; that they derive from the actions and agency of actors; and that these processes can be traced out through fairly direct sociological and historical research. And we will understand too that claims about the reality of "capitalism", the world financial system, or fascism are to be understood less weightily than they first appear. Capitalism exists in a time and place; but it is understood to be an ensemble of relations and actions by the people of the time. It is not a "thing" in the way that deoxyribonucleic acid is a thing.
These thoughts should perhaps lead us to consider that the topic of realism is less important in sociology, political science, and economics than it might appear to be. Social scientists have every reason to be realist about the actions, relations, and interactions of individuals. They are justified in thinking that the practices of education and socialization that bring children to adulthood are "real" and can be empirically investigated. And they are justified in observing that there are higher-order configurations of action, power, and social relationship that are "real", insofar as they are present in the activities of the individuals who constitute them and they possess some stable characteristics over time. In other words, social scientists are justified in postulating the social reality of the social processes and institutions that they postulate and investigate. But this is a very weak and qualified conception of realism, and it suggests a fairly weak social ontology.
It will be noted that this conclusion is somewhat in tension with the argument I offered in the prior post on "flat social ontology". That's the virtue and the challenge of open-source philosophy: conclusions and arguments shift over time.