Constituents of Matter / 6 / 6.2 / 6.2.3

6.2.3 How Much Truth Is There In Modern Scientific Theories?

There is a shared sense pervading the community that science is progressively revealing to them the true structure of the world. The objects inhabiting that world are real and appear to influence each other’s behavior according to equally real laws that modern science can and does discover. This sense that science discovers reality is encouraged by two characteristics of the scientific project: it incorporates an increasingly large domain of our quantified experience, and the theories required to explain that experience appear to form an increasingly unified and orderly edifice. The first characteristic reflects the success science seems to have had in explaining almost all the ordinary observations we perform to ascertain the quantified behavior of objects of experience as well as almost all the predicated observations we perform to ascertain the behavior of objects of explanation. The second characteristic is revealed in the hierarchical structure of scientific theory, with modern physics undergirding other natural sciences and itself becoming increasingly unified with weak, electromagnetic, strong, and perhaps even gravitational interactions brought together under the same formalism. These two features of the scientific project, extensive coverage and unified structure, strongly suggest that science does indeed approach an independently existing reality which it fittingly captures in its own peculiar conceptual language; in other words, its theories are true.

While this essay does not encourage us to think otherwise, it does teach us to be cautious about generalizations concerning the ontologies of objects and the objectivity of the laws that we may think govern their behavior. We thus had argued that, while truth is indeed to be found in theories which explain ordinary measurements, such is not fully the case with theories which explain predicated measurements. We showed that, for theories explaining predicated measurements, the agreement between theory and observation is no longer a simple fitting of theory to reality but merely a manifestation of the internal consistency of that theory. Explaining an observation predicated upon the need to manufacture its object is not an attempt at reflecting any reality but rather is an exercise in exploring the full conceptual content of the object of explanation which had been manufactured. Thus, for instance, the theory of elementary particles is not a discovery of what is objectively inside the atom, but only a process of refining what it is that we mean by the concept atom.

While there seems to be no truth directly acquired in conducting a predicated observations, there is nevertheless some degree of indirect truth attained through this process of refining the concepts we use to explain ordinary observations. By exploring the meaning we must assign to an object of explanation as our experience involving it expands, we may increase that object's ability to explain the associated ordinary observations. For instance, the oscillator which Planck had introduced to explain radiant heat enlarged the previous meaning we associated with that concept, enlargement which allowed Einstein to explain the hitherto unexplained temperature dependence of the specific heat of solids. By thus making the theory fit reality more closely, this process of refining what it is that we mean by an oscillator has allowed the theory to carry more truth.

Thus, our essay suggests that the question concerning the truth content of scientific theory is more nuanced than what it is normally thought to be. The ontological difference between objects of experience and objects of explanation complicates the matter. It turns out that scientific theory is true only to the extent to which it addresses the behavior of objects of experience. When, however, it explains the observation of an object of explanation, scientific theory contains truth only indirectly, that is, only to the extent that the more encompassing definition of the concept involved improves its ability to explain the observations which had commandeered its introduction in the first place.