Critical realism and scientific inquiry: natural vs social science (Part I: Open and Closed Systems)

Critical realism is a philosophy of social science originally pioneered by Roy Bhaskar. Originally quite useful in laying out a theoretical model of experienced reality that sought to explain why it is even possible to perform scientific research at all, his later work took things in a rather esoteric and, frankly, mystical direction. But the work on critical realism that did not take this "spiritual turn" is quite interesting, especially in how it seeks to explain why the methods of natural science and the methods of social science must be significantly different.

The premise of critical realism is realist: it presumes that there is a reality "out there" that exists independently of our knowledge of it. The means by which we learn about this reality is fallible, affected (but not determined) by our pre-existing theories about it, and different aspects of reality have different methods through which those aspects can be studied. Critical realism, as a theory about scientific inquiry, puts forward some ideas about the different nature of physical and social objects of study, and these ideas demonstrate differences in the way that scientific inquiry ought to work for the natural and social sciences.

Open vs Closed Systems

In natural sciences, the preferred method of study is the laboratory. In the terminology of critical realism, this is referred to as a closed system: a single aspect of reality is to be studied, so parts of reality that are irrelevant to that study are artificially removed so as not to affect the outcome. Even in situations where study isn't specifically in a laboratory, the goal is still much the same: close the system so as to be able to focus specifically on one aspect of external reality. In critical realist terminology, the goal off the closed system is to isolate and prove the existence of a "causal mechanism". In natural science terminology, a causal mechanism is a scientific law.

Closed systems are artificial environments. This becomes problematic when the object of study is social reality. According to critical realist philosophy, most attributes of social reality are not the result of simple, easy to isolate causal mechanisms, but stem directly from the interaction of multiple causes; each cause by itself would not produce even remotely the same effect by itself. Additionally, some effects may be actually negated by other causes, effectively removing evidence of the effect, even though the cause of the expected effect is present and salient. While isolating and testing a single cause-and-effect relationship can be done in some situations, there are a whole host of causal mechanisms that cannot be isolated for study, as the emergent effects of the interactions between those mechanisms forms a vital part of the picture of what is going on. This may not be so bad if there are only a few such interacting mechanisms, but in even the simplest social system, there are a whole host of them. And different social systems and situations can have entirely different causal mechanisms in operation.

To complicate matters even further, social reality is in part defined by its relationship to other parts of that reality, social or otherwise. Even before critical realism, an ongoing criticism of laboratory social science was that social scientific laboratory experiments don't explain what people do, but only what people do when they're in the social environment a laboratory. Trying to close off a social system for study potentially changes how that social system works, which means that any results from such a study cannot readily be generalised to social systems which have not been artificially closed off in the same way.

The goal of social scientific study, similar to attempts in natural science to uncover scientific "laws", is to discover causal mechanisms that explain the observed behaviour of an external reality. But while the natural scientist can observe closed systems and interpret them through deduction, along with some amount of induction (i.e. to consider how generalisable the experimental findings might be), the social scientist has to observe open systems. And while the social scientist may be able to make some deductive conclusions from such observations, they must make make much greater use of inductive reasoning to try and figure out what causal mechanisms are present and salient in a particular social system.  In order to consider what causal mechanisms might even potentially be present, they must also make use of what critical realists call "retroduction": the attempt to explain an aspect of reality by positing what pre-conditions are necessary for such an aspect of reality to exist.

Both induction and retroduction are less reliable tools of inquiry than deduction, As social science must rely on these tools to a greater extent than natural science, the claims of social science tend to be less reliably true than claims made in the natural sciences. Such "laws" as can be posited from these methods of inquiry are also much harder to test across different social systems and situations. This means that the explanations provided by social science are much more tentative than in natural science, and the extent to which findings from the study of one area of social reality can be applied to a different area of social reality is much less clear than in it is in the study of reality undertaken by the natural sciences.

I actually wrote this in an attempt to clarify my own understanding of critical realism's understanding of the differences between natural and social science. It's worked (I think), but it's taken longer for me to explain the first difference between them  than I expected it to. The other main difference - the element that interpretation plays as both something that is applied to findings in all types of scientific study, and as something that is also studied by social science - will have to wait for Part II.