developed a computerized cognitive system ECHO, an acronym for “Explanatory Coherence by Harmony Optimization”, in order to explore the operative criteria in theory choice by mechanically simulating noteworthy past episodes in the history of science. His system described in his Conceptual Revolutions simulated the realization of the aim of maximizing “explanatory coherence” by replicating various episodes of theory choice. In his system “explanation” is an undefined primitive term. He applied his system ECHO to several revolutionary episodes in the history of science including (1) Lavoisier’s oxygen theory of combustion, (2) Darwin’s theory of the evolution of species, (3) Copernicus’ heliocentric astronomical theory of the planets, (4) Newton’s theory of gravitation, and (5) Hess’ geological theory of plate tectonics.
In reviewing his historical simulations Thagard reports that ECHO indicates that the criterion making the largest contribution historically to explanatory coherence in scientific revolutions is explanatory breadth – the preference for the theory that explains more evidence than its competitors. But he adds that the simplicity and analogy criteria are also historically operative although less important. He maintains that the aim of maximizing explanatory coherence with these criteria yields the “best explanation”.
Explanationism, maximizing the explanatory coherence of one’s overall set of beliefs, is inherently conservative. The ECHO system appears to document the historical fact that the coherence aim is psychologically satisfying and occasions strong motivation for accepting theories, while theories describing reality as incoherent with established beliefs are psychologically disturbing. But progress in science does not consist of maximizing the scientist’s psychological contentment. Empiricism eventually overrides coherence when there is a conflict with new evidence. In fact defending coherence has historically had a reactionary effect. For example Heisenberg’s revolutionary indeterminacy relations, which contradict microphysical theories coherent with established classical physics including Einstein’s relativity theory, do not conform to ECHO’s maximizing-explanatory-coherence criterion.
Readers wishing to know more about the philosophy of Thagard are referred to BOOK VIII below.
4.06 Contemporary Pragmatist Aim
The successful outcome of basic-science research is explanations made by developing theories that satisfy empirical tests, and that are thereby made scientific laws that function in scientific explanations.
The principles of contemporary pragmatism including its philosophy of language evolved through the twentieth century beginning with the autobiographical writings of Werner Heisenberg, one of the central participants in the historic development of quantum theory. This philosophy is summarized in Section 2.03 above in three central theses: relativized semantics, empirical underdetermination and ontological relativity, which are not repeated here. Readers wishing to know more about the philosophy of Heisenberg are referred to BOOK IV below.
The institutionally regulated activities of research scientists may be described succinctly in the pragmatist statement of the aim of science. The contemporary research scientist seeking success in his research may consciously employ the aim as what some social scientists call a “rationality postulate”. The institutionalized aim of science can be re-expressed as such a pragmatist rationality postulate:
The institutionalized aim of science is to construct explanations by developing theories that satisfy empirical tests, and thereby make scientific laws that function in scientific explanations.
Pragmatically, however, rationality is not some incorrigible principle or intuitive preconception. The contemporary pragmatist statement of the aim of science is a postulate in the sense of an empirical hypothesis about what has been responsible for the historical advancement of basic research science. Therefore it is destined to be revised at some unforeseeable future time, when due to some future developmental episode in basic science, research practices are revised in some fundamental way. Then some conventional practices deemed rational today might be dismissed as misconceptions, and perhaps superstitions, as are the romantic and positivist beliefs today. The aim of science is more elaborately explained in terms of the other three functional topics as sequential steps in the development of explanations.
The institutionalized aim can also be expressed so as not to impute motives to the successful scientist, whose personal psychological motives may be quite idiosyncratic. Thus the contemporary pragmatist statement of the aim of science may instead be phrased in terms of a successful outcome instead of a conscious aim imputed to scientists. The successful outcome of basic-science research is an explanation produced by developing theories that satisfy critically empirical tests, and that are thereby made scientific laws that function in scientific explanations.
The empirical criterion is the only criterion acknowledged by the contemporary pragmatist, because it is the only criterion that accounts for the advancement of science. Historically there have been other criteria, but whenever there has been a conflict, eventually it is demonstrably superior empirical adequacy that has enabled a new theory to prevail. This is true even if the theory’s ascendancy has taken many years or decades, or even if it has had to be rediscovered, such as the heliocentric theory of the ancient Greek astronomer Aristarchus of Samos.
4.07 Institutional Change
Change within the institution of science is change made under the regulation of the institutionalized aim of science.
Institutional change is the historical evolution of scientific practices involving revision of the aim of science, which may entail revision of its criteria for criticism, its discovery practices, or its concept of explanation.
Institutional change in science must be distinguished from change within the institutional constraint. Philosophy of science examines both changes within the institution of science and historical changes of the institution itself. But change of the institution is typically recognized only retrospectively due to the distinctively historical uniqueness of each episode and also due to the need for eventual conventionality for new basic-research practices to become institutionalized.
In the history of science institutionally deviate practices, innovative instruments and unconventional concepts that yielded successful results are initially recognized and accepted by only a few scientists. As Feyerabend emphasized in his Against Method, in the history of science successful scientists have often broken the prevailing methodological rules. But the successful departures eventually become conventionalized. By the time they are deemed acceptable to the peer-reviewed literature, reference manuals, encyclopedias and student textbooks, the institutional change is complete and has become the conventional wisdom.
Successful researchers have often failed to understand the reasons for their unconventional successes, and have advanced or accepted erroneous methodological ideas and philosophies of science to explain their successes. One of the most historically notorious such misunderstandings is Isaac Newton’s “hypotheses non fingo”, his denial that his law of gravitation is a hypothesis. Nearly three centuries later Einstein demonstrated otherwise.
4.08 Philosophy’s Cultural Lag
Adequate understanding of successful departures from institutionalized basic research is elusive even for philosophers. There exists a time lag between the evolution of the institution of science and developments in philosophy of science, since the latter depend on the realization of the former. For example more than a quarter of a century passed between Heisenberg’s philosophical reflections on the language of his indeterminacy relations in quantum theory and the consequent emergence and ascendancy of the contemporary pragmatist philosophy of science in academic philosophy.
4.09
