1 In Defense of Realism and Scientism Mario Bunge

Tennessen wishes to kill several birds with a single shot: sensationalism, realism, and scientism. We agree that the former is untenable, but I will try to defend the other two, which are birds of a different feather.

First of all, it is necessary to recall that there are two main kinds of realism in matters of knowledge: naive and critical. The naive realist holds the world to be as he perceives it. Tennessen has effectively dis-posed of this kind of realism, but not, however, of critical realism. The latter distrusts the sense data and, far from attempting to account for the world in terms of them, encourages the building of sophisticated con-ceptual systems (theories). These always include some concepts that have only a remote relation with reality or, in the case of mathematics, none at all. However, a theory cannot claim to explain a certain domain of facts unless some of its concepts do refer, no matter how deviously, to those facts. For example, in quantum theory a ray in a Hilbert space (a highly abstract construct) is supposed to represent the state of some real thing, such as an electron or a photon.

I claim that critical realism is not only consistent with science and technology but also a component of the philosophical background of the latter. Indeed, the researcher who manipulates instruments when making measurements on the objects that he is studying presupposes the independent reality of such instruments, and he assumes, at least tentatively, that his objects of study exist on their own. And the theorist, unless he is a pure mathematician, assumes that his theories refer to real, or at least pOSSibly real, entities-be it atoms or stars, grasshoppers or people.

Mario Bunge Foundations and Philosophy of Science Unit, McGill University, Mon-treal, Quebec, Canada H3A 1 W7.

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24 Mario Bunge

In other words, neither the experimentalist nor the theorist creates the world: both just study it. To be sure, the former may design and assemble new things, such as artifacts, and he may even create new species of things; and the creative theorist creates new concepts, just as the creative technologist creates new designs or plans. But all of them assume the autonomous existence of the external world, and they all presuppose that it is their task to explore, understand, or alter it. Were this not so, they would be regarded as myth makers or fiction writers.

True, some physicists, from Niels Bohr to Bernard d'Espagnat, have claimed that quantum theory has refuted realism: that it has rendered the distinction between the object of study (e.g., an atom) and the sub-ject (e.g., an experimenter) untenable. However, it is easy to show that this is a mistake. First of all, every careful experimenter takes pains to avoid influencing his objects of study or, at least, to try and estimate the size of the perturbation that his actions cause. Were this not so, the dif-ferences between control group and experimental group, and between thing observed and observation probe, would be nonexistent and the experimental method would be inapplicable. Secondly, the general for-mulas of quantum theory contain no explicit reference to any subjects or experimenters, or even to experimental set-ups. And those few that do refer to the latter treat them as physical entities, not as psychophysi-cal ones. This is why quantum theory is successfully applied in astronomy, which deals with objects that are beyond experimental con-trol. In conclusion, quantum physics is just as realistic as classical physics. The main difference between the two is that, whereas in classi-cal physics every property has a sharp value at any time, in quantum physics most properties are unsharp (or distributed). In other words, whereas classical states are simple, the typical quantum state is a super-position of simple states. (See Bunge 1967a and 1973 for details on the subjectivistic and the objectivistic interpretations of quantum theory.)

As for scientism, I take it to be quite different from Tennessen's "belief in some sort of scientific world view miraculously emanating from the main bulk of the testimony of the senses or so-called scientific results." The brand of scientism I defend boils down to the thesis that scientific research (rather than navel contemplation or the reading of sacred texts) can yield the best (truest and deepest) possible knowledge of real (concrete, material) things, be they fields or particles, brains, or societies, or what have you. Because scientific research involves not only perceiving but also conceiving and doing, the scientific world view at any given time cannot "emanate" from the testimony of the senses alone, even less in a miraculous fashion. Furthermore, because science advances, our scientific world view does not stay put. For example,

1 In Defense of Realism and Sdentism 2S

unlike most nineteenth-century scientists, we now believe in objective randomness and in basic probabilistic laws; we also believe that the mind is not an entity separate from the living brain; and we believe in some degree of economic determinism.

I take it that scientists are among the firmest believers in scientism: otherwise, I would be unable to understand why they devote them-selves to scientific research. And, of course, I include the scientific method among the general or philosophical presuppositions or pre-requisites of scientific research. In other words, I take the scientific method, rather than any special results of scientific research, to be the very kernel of scientism. Consequently I cannot accept Tennessen's implicit approval of Feyerabend's antimethodology or "epistemological anarchism" -the latest version of radical skepticism. The "principle" of this doctrine is that anything goes. This is not really a principle but a license to do anything and believe anything. Hence it does not help the conduct of inquiry and it is not the correct answer to narrow authori-tarian (or dogmatic) methodologies such as classical positivism (and its psychological companion, radical behaviorism). It is simply a mark of intellectual emptiness and irresponsibility. To be sure, we must all be skeptical and ready to change some of our most cherished beliefs if we are to call ourselves scientists or philosophers. However, doubt is a means, not an end. The goal of scientific (and humanistic) research is to understand the world with the help of theories that have stood a num-ber of tests, among them those of observation or experiment. (See details on scientific methodology in Bunge, 1967b; on scientific realism in Bunge, 1983a and 1983b.)

In conclusion, I agree with Tennessen that perception is limited and moreover species-specific (e.g., anthropocentric) as well as con-taminated with ideas and expectations. But I disagree with his conclu-sion that this fact refutes realism and scientism. It refutes only pre-scientific (naive) realism and the uncritical (hence unscientific) accep-tance of every single result of scientific research. Science is fallible but not pure fiction; it is skeptical but not nihilistic. And science changes, sometimes in a revolutionary manner, but never in a total way: no scientific change, however deep, erases completely the achievements it replaces. Just as in the cases of individual development and of the evolution of populations, the advancement of scientific knowledge is discontinuous in some respects and continuous in others. This explains why even "those who engage in physiological psychology can continue to learn from the achievements of introspective and behaviorist psy-chology while criticizing their shortcomings. Revolution, whenever needed; anarchy, never.

26 Mario Bunge

1. References

Bunge, M. (1967a). Foundation of physics. New York: Springer-Verlag. Bunge, M. (1967b). Scientific research (2 vols.). Berlin and New York: Springer-Verlag. Bunge, M. (1973). Philosophy of physics. Dordrecht: Reidel. Bunge, M. (1983a). Exploring the world. Dordrecht and Boston: Reidel. Bunge, M. (1983b). Understanding the world. Dordrecht and Boston: Reidel.