Scientific Realism vs. Constructive Empiricism

            There exists today, an innumerable amount of theories that attempt to better our understanding of this world. Yet, some of the most intriguing theories come from the question: how does one understand a scientific theory? This is where one can break down the interpretation of theory into two distinct categories, realism and anti-realism.

 

           

Scientific realism holds two things to be true. The first is that theories should be taken literally, as science aims to paint a picture of the truth of the world. Bas Van Fraassen makes it a point to identify that this can be read incorrectly by someone who is not comfortable with realism. He explains that a na�ve person may believe that this should be interpreted as, “science tells a true story,” when it should be understood that science only aims to do so (1066, Fraassen). Scientific realism should determine that “scientific activity” is an “enterprise of discovery, as opposed to invention” which means that science should explain what already exists and not what we are creating (1065).

 

The second objective of realism is that, to accept a scientific theory, is to believe that it is true. This explanation is, ironically, not to be taken literally. Instead, realists understand that science is a never ending search of the truth and that it constantly gets updated and revised, retracting previous ideas with the finding of new information. Van Fraassen explains that “the task we have at this point is to find a statement of scientific realism that… does not saddle the realists with unacceptably strong consequences” (1065). From this, Van Fraassen explains that “acceptance tout court,” or the tentative acceptance of a belief to be tentatively true, is enough to fulfill this requirement (1067). From all of these ideas comes the accepted definition of scientific realism: “Science aims to give us, in its theories, a literally true story of what the world is like; and acceptance of a scientific theory involves the belief that it is true” (1066).

 

            Anti-realism proposes a contrasting perspective on the understanding of scientific theory. There are two branches of anti-realism, with Van Fraassen being the latter of the following. An anti-realist can either believe that scientific theories need not be understood literally or that theories need not be true in order to be considered successful. Van Fraassen’s supposition was termed “constructive empiricism,” and it is in concordance with realism that theories should be taken literally. However, a constructive empiricist believes that when a scientist makes a proposal, they “display” it with all of its credentials attached, rather than assert it to be true (1067). From this viewpoint came the accepted definition that, “Science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate” (1069).  

 

As can be seen from the definition of constructive empiricism, “empirical adequacy” replaces the word “true” from the realist definition. A theory can be termed “empirically adequate” only if it is correct about observable bodies, which are acknowledged entities which may or may not exist. Something can be considered “observable” to humans if they can be recognized by any of our common human sensory abilities. Nowhere in constructive empiricism does truth about unobservables come into play; however, realists believe that they can make claims about unobservables as if they were observables due to the “inference to the best explanation” method. The idea behind this method can be explained simply through the mouse example employed by Van Frassen (1077). If we have not seen a mouse in our home, but everything is as it would be if there were to be a mouse in the home, then one should, logically, claim that there is a mouse in one’s home. In this way, realists believe that an unobservable can serve as an observable through inference.

 

            At the beginning of my research, I believed that I sided with the constructive empiricists on the idea that one can only make claims pertaining to observables. I thought that, because we cannot scrutinize an unobservable entity, that that would render it to be an enigma left to be solved in the future with the help of advanced technology. However, in reading on to the “inference to the best explanation” theory, I began to waver. I believed that this seemed like a legitimate idea due mostly to the mouse example. It seemed logical that, if there were mouse droppings or chew marks on the cabinets, that there should be a mouse in the home; thereby, saying that we are able to treat observables and unobservables as one.

 

Yet, Van Fraassen made it a point to distinguish between “observing” and “observing that” (1072). He said that observables are only observables when one can monitor an entity with our basic human senses. I believe that this invalidates the mouse example on the basis of another of Van Fraassen’s examples, the Stone Age man. If a man from the Stone Age were to resurface and walk into the home with the chew marks on the cabinets, he would see the marks and be able to observe them; however, he would not know that it was atypical of cabinets to have markings on them. He may, in fact, believe those markings to be a part of the design of the cabinet and suspect no mouse at all. If he realized that they were bite marks, he may not know exactly what type of animal caused those markings. It would only be through learning about household rodents and insects that he could “observe that” it was a mouse that was invading that home. Because of this, I would say that, with our basic sensory skills, one cannot “observe” an unseen mouse in the home, but rather, must “observe that” there is a mouse in the home, rendering this not to be an observable at all. Because these entities cannot qualify as an observable, claims about them cannot be extrapolated to unobservables, thereby voiding the inference to the best explanation method. After doing further reading, I came across instrumentalism, which purports that unobservables are meaningless, as they can be either true or false. This strengthens my argument as both constructive empiricism and instrumentalism both agree that theories do not aim for truth about unobservables. Due to all of this, I stick with my previous conviction of siding with the constructive empiricists.

 

 

Philosophical Schizophrenia

Today in class we tried to get clear on what exactly distinguishes the scientific realist from the constructive empiricist (who accepts a form of anti-realism).  It became clear that these are competing philosophical views concerning 1) the real aim of scientific theories and 2) what one commits oneself to in adopting or accepting a scientific theory.  According to both views, the aims of science require that our theories be empirically adequate, and accepting a scientific theory will involve the belief that the theory is empirically adequate.  The divisive issues concern 1) whether or not empirical adequacy is ALL we should expect from a scientific theory, and 2) whether or not the belief that a theory is empirically adequate is ALL that is involved in accepting that theory.

The realist thinks that we are right to expect more from scientific theories, and that we are committed to more when we accept them–we are right to expect that our scientific theories should provide true statements about the world (and not just about its observable aspects), and scientists are committed to the existence of the entities that are postulated within the theories they accept.

The constructive empiricist thinks that empirical adequacy is all we should expect and that it is all that scientists are committed to when they accept a theory. 

By the end of class, it seemed that some of us were fairly convinced that the constructive empiricist is right.  Realism appears to move us beyond properly scientific considerations and into the realm of metaphysics; perhaps even leading to a kind of dogmatism that conflicts with the proper scientific attitude.  At the same time, however, constructive empiricism seems to leave the success of science entirely unexplained–realism at least tries to offer an explanation for the empirical adequacy of certain theories; i.e., they ‘save the appearances’ because the entities they postulate actually do exist and actually do explain the characteristics of observable objects.  If the anti-realist is right, there are empirically adequate theories and there are theories that are not empirically adequate–the former tend to survive and the latter tend to die off.  This Darwinian account of the success of science is not very satisfying to those who are interested in understanding what it is about certain theories that explains their empirical adequacy.

If Musgrave is right, the constructive empiricist recommends a kind of philosophical schizophrenia and, as if this weren’t bad enough, his or her position may well be incoherent.  It is only if we artificially disassociate the ‘scientific world picture’ from our everyday beliefs and attitudes that we can make the fine distinction between accepting that a theory is empirically adequate and accepting that the theory is true.  In the case of ordinary empirical objects, there is no difference between the two views–they both agree that scientific theories make true claims about these objects.  The whole case, then, rests on the observable/unobservable distinction, which is one that the constructive empiricist has difficulty accounting for on his or her own terms:

Is the statement that there are unobservable objects true? 

If so, then we appear to be able to make true claims about unobservable objects.
If not, then why are we placing so much emphasis on this distinction in making a big deal about the difference between realism and constructive empiricism?

For next time, I would like us to focus on Section II (Realism and Explanation) and on the concluding paragraphs (p 1110) of Musgrave’s essay “Realism versus Constructive Empiricism”.  Is Musgrave effective in salvaging a commitment to realism?  Why or why not?  

Van Fraassen’s view

Van Fraassen says that we should understand realism as holding that it is part of the aim of science that the claims it makes about unobservable as well as observable entities literally true. Van Fraassen explains further that to accept a scientific theory is to believe that these claims are true beyond a doubt. To understand the contrast he draws between realism and constructive empiricism, we need to know what he means by empirical adequacy:  a theory is empirically adequate if the claims it makes about observable entities are true? Regardless of whether its claims about unobservable phenomena are true or false. With this notion in hand, van Fraassen explains that constructive empiricism holds that scientific theories aim at theories that are empirically adequate, and that the only belief involved in acceptance of a scientific theory is belief that the theory is empirically adequate.. A feature of van Fraassen’s view that I find puzzling is the sharp contrast he draws between unobservable entities, and entities that are observable but have not actually been observed. It might seem that van Fraassen’s arguments that we should have beliefs about the truth of claims about observable things that we have not yet observed would push him in the direction of full-fledged realism, while his arguments for not having beliefs about unobservable entities would push him toward skepticism about anything we haven’t observed. 

Van Fraassen’s Anti-realism

In arguing with the realist standpoint, Van Fraassen postulates his form of anti-realism called Constructive Empiricism. Van Fraassen initially looks at realism and gives the statement that scientific realism tells us that “science aims to give us, in its theories, a literally true story of what the world is like; and acceptance of a scientific theory involves the belief that it is true” (1066). Van Fraassen goes on to say that the aims does not actually involve individual motives and includes the example of playing chess showing how aims and motives are dissimilar.

Van Frassen gives the alternative to  realism as his Constructive Empiricism. This theory accordingly states: “Science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate” (1069). According to Van Fraassen this empirical adequacy means that the theory, if true, has a model that all actual phenomena fit with in it. This points to acceptance of a theory as being a sort of commitment that all phenomena that has been or ever will be, will fit within that theory.