5.2 The unificationist account
5.2.2 The epistemic question
Friedman also reports a further point of interest: the familiarity views are local in the sense that understanding stems from the relation between the explanans and the explanandum. In this vein, it is natural that one ends up trying to find some special epistemological status between these two. Instead, Friedman defends a global view of scientific understanding, one that constitutes a cognitive relation between the explanandum and the total corpus of our beliefs.38 Thus understood, the unificationist theory of explanation facilitates scientific understanding without assuming familiarity, but rather demanding unification with the total corpus of beliefs. In this sense, scientific understanding becomes a global affair, where an explained phenomenon is unified with the total set of accepted scientific beliefs, and thereby somehow accommodated into the total number of accepted phenomena.
By the same token, Eric Barnes argues that Friedman’s account of understanding has two important virtues; first, by “accommodating the insight that understanding is not generated by any sort of intelligibility transfer and, second, [by] providing an answer to the question of how it helps our understanding to derive one puzzling phenomenon from another” (Barnes, 1992, 5). I have argued for the first virtue above; let me now use the second virtue for showing how understanding is achieved according to the unificationist.
Let us return to Kitcher’s quotation above. According to him, the aim of sci-entific explanation is to increase our understanding of the world by decreasing the number of phenomena that we must take as independent or brute. Such a decrease is accomplished by means of unifying an explained phenomenon with our total cor-pus of scientific beliefs; that is, by ‘seeing connections’ and ‘common patterns’ that initially escaped our comprehension and are now becoming intelligible to us by co-hering with our set of beliefs. The criterion for unification, as Kitcher points out at the end of his quotation, is based on the idea thatE(K) is a set of derivations that makes the best tradeoff between minimizing the number of patterns of derivation employed and maximizing the number of conclusions generated.39 Hence, by us-ingE(K) for explaining a brute phenomenon one exhibits connections and common patterns that cohere with the totality of our corpus of beliefs and can thereby be unified. Unification, then, yields understanding because it decreases the number of phenomena that we must accept as brute or independent by unifying them with our total corpus of scientific beliefs.40 In the words of Friedman, “[scientific expla-nation] increases our understanding of the world by reducing the total number of independent phenomena that we have to accept as ultimate or given. A world with fewer independent phenomena is, other things equal, more comprehensible than with more” (Friedman, 1974, 15). Let us note that explanation, unification, and
under-standing are three interlaced concepts that cannot be individually studied, but must be jointly appreciated. Indeed, by means of explaining, one gains understanding of the world, which comes hand in hand with unification since explanation consists in unifying a multiplicity of phenomena with a corpus of beliefs.
Friedman makes use of a series of examples that allow him to spell out the process of understanding a brute fact via explaining it. Let me briefly reconstruct one of his examples:
Consider a typical scientific theory (e.g., the kinetic theory of gases) [...] This theory explains phenomena involving the behavior of gases [...] [adding] a significant unification in what we have to accept. Where we once had three independent brute facts (that gases approximately obey the Boyle-Charles law, that they obey Graham’s law, and that they have the specific-heat ca-pacities they do have) we now have only one (that molecules obey the laws of mechanics) [...] Once again, we have reduced a multiplicity of unexplained, independent phenomena to one (Friedman, 1974, 14-15. Emphasis original)
Kitcher endorses these same ideas: “Friedman argues that a theory of explanation should show how explanation yields understanding, and he suggests that we achieve understanding of the world by reducing the number of facts we have to take as brute. [...] Something like this is, I think, correct” (Kitcher, 1989, 431). In this vein, by instantiating schemata like Mendel’s, we explain why certain distribution of phenotypes have specified probabilities and thereby are able to unify such a phenomenon of transmission of traits through pedigrees with Mendelian theory.
It follows that the unified phenomenon is no longer ‘brute,’ for now it has been subsumed under a larger corpus of beliefs about genetic theory, unifying with it, and therefore increasing the general scientific understanding and coherence of biology.41 Strictly speaking, these ideas are not exclusively unificationist since their roots are in the ‘unofficial’ view of the covering law model.42 Herbert Feigl, for instance, wrote, “The aim of scientific explanation throughout the ages has been unification, i.e., the comprehending of a maximum of facts and regularities in terms of a mini-mum of theoretical concepts and assumptions” (Feigl, 1970, 12); and Hempel made a similar point when he said:
What scientific explanation, especially theoretical explanation, aims at is not [an] intuitive and highly subjective kind of understanding, but an objective kind of insight that is achieved by a systematic unification, by exhibiting the phenomena as manifestations of common, underlying structures and processes that conform to specific, testable, basic principles (Hempel, 1966, 83. See also (Hempel, 1965, 444)).
The question that still remains unanswered, however, is what do Kitcher and
Fried-ysis of the notion of understanding is completed with the study of these concepts.
The problem is that neither Kitcher nor Friedman have much to say about them.
As a result, I offer here a brief analysis of current discussions in the philosophical literature.
Two particularly interesting (though conflicting) positions stand out among the rest: Ludwig Fahrbach who takes brute facts as facts for which no direct explanation exists; and Barnes, who takes them as facts for which the explanation is missing. Let me briefly elucidate these positions. To Fahrbach’s mind, brute facts are ‘starting points’ in the order of the empirical world; that is, facts that have no predecessor, for instance the Big Bang constitutes one.44 The importance of a brute fact, then, is that it is closely related to a ‘single fact’ (e.g., the background temperature of the universe), which is a byproduct of a brute fact (e.g., the Big Bang). A brute fact, therefore, is unexplainable in itself, but it contributes to exhibiting the place of a single fact in the order of the empirical world.45
The other interpretation belongs to Barnes who has a more complex (and more compelling) analysis. To Barnes’ mind there are two kinds of brute facts: epistem-ically brute facts (i.e., those whose explanation, which we assume exists, remains unknown), andontologically brute facts (i.e., facts with no explanatory basis beyond themselves, such as the ultimate laws of physics or the origins of the universe)46 There are some affinities between Barnes’ ontological interpretation of brute fact and Fahrbach’s. However, the difference between these two scholars lies in Barnes’
epistemic interpretation which takes brute facts as representing a temporal ‘gap’ in our understanding of the world, a ‘gap’ that does not need to remain an enigma but which is overcome by means of explanation. According to Barnes, then, it is through the process of explaining brute facts that we obtain understanding of the ultimate mysteries of the universe.
I believe that Barnes’ positions, rather than Fahrbach’s, is the correct way to interpret Kitcher and Friedman’s notion of brute or independent phenomena. I have two reasons for holding this conviction. First, Barnes’ naturalistic position is in better accordance with Kitcher’s own naturalism. To the latter, the world does not comprise mysterious or magical entities that cannot, sooner or later, be understood within the scientific method.47 Second, both Kitcher and Friedman seem to take a brute fact as some sort of gap in our understanding that can be and must be overcome through explanation. Indeed, there is no single reference that I have been able to find of brute facts as unexplainable in themselves. For these two reasons, I take a brute fact as an explanandum that we do not quite understand but that we have, or we will have, the means to explain.
Thus understood, let me reconstruct the unificationist answer to Kim’s question in the following way: the world becomes a more transparent and understandable place when we reduce the number of facts that we must take as brute or independent.
Such ‘reduction’ is taken in the sense of unification. It is achieved by the process of incorporating the explained phenomena into our system of beliefs and of seeing how they form part of a unified picture of the empirical world.
Allow me now to discuss how the unificationist account provides a conceptual framework for explaining by a computer simulation.