B. Critical Realism: The Original ‘Bridge’ Between Science and Religion.

In his ground-breaking 1966 publication, Issues in Science and Religion, Ian G. Barbour laid out a series of well-crafted arguments involving issues in epistemology (the kinds of knowledge we have), language (how it is expressesd), and methodology (how it is obtained and justified). Together these arguments provided the ‘bridge’between science and religion which has, more than any other work, made possible the developments of the past four decades. He has explored these arguments in detail since then, principally through his 1990 Gifford Lectures, together with their revisions in 1997and 2000. Barbour’s pioneering vision continues to bear much of the now burgeoning flow of traffic. From the outset, Barbour used the term “critical realism”to stand for the specific set of arguments he developed in 1966, as have many other scholars since then.

Barbour viewed critical realism as an alternative to three competing interpretations of scientific theories: (1) classical or “naive” realism: scientific theories provide a ‘photographic’ representation of the world; (2) instrumentalism: scientific theories are mere calculative devices, and (3) idealism: scientific theories depict reality as mental. Instead, from a critical realist perspective, scientific theories yield partial, reviasable, abstract, but referential knowledge of the world. Scientific theories are expressed linguistically through metaphors and models. Drawing on Max Black, Mary Hesse, Donald Schon, and others, Barbour defined ‘metaphor’ as an open-ended analogy whose meaning cannot be reduced a set of literal statements.Scientific models, in turn, are systematically developed metaphors. “(M)odels and theories ... selectively represent particular aspects of the world for specific purposes... (They) are to be taken seriously but not literally.”

Barbour then turned to the current discussion of scientific methodology, with major breakthroughs by such philosophers of science as N. R. Hanson, Gerald Holton, Thomas Kuhn, Michael Polanyi, Steven Toulmin, and with special emphasis on the writings of Imre Lakatos.He began with the empiricism of Carl Hempel, whose ‘hypothetico-deductive’ method brought together inductivist and deductivist approaches to the construction and testing of theories vis. Popperian falsificationism.In the 1960s, this method was fundamentally recast. It was now seen to operate within both the historicist and contextualist elements which characterize the scientific community. These elements include the ‘theory-laddenness of data’, the presence of intersubjectivity rather than strict objectivity in scientific rationality, the structure of science through paradigms and their revolutions in the history of science, the presence of metaphysical assumptions about nature in scientific paradigms, and the role of aesthetics and values in theory choice. Scientific theories are a human construction and their conclusions are inherently tentative and subject to revision. Nevertheless, according to Barbour, they are to be assessed by four criteria which are reasonably trans-paradigmatic: agreement with data, coherence, scope and fertility.

Barbour used these criteria to articulate what he called a “critical realist” theory of truth. Like classical realism, the meaning of truth in critical realism is correspondence with reality (i.e., reference) and the key criterion of truth is agreement of theory with data. But we often have only indirect evidence for our theories; moreover, networks of theories are tested together. Thus internal coherence and scope also serve as criteria of truth, as stressed by rationalists and philosophical idealists. Even this is insufficient when competing theories are equally coherent and comprehensive; hence fruitfulness serves as a fourth criterion of truth, as pragmatists, instrumentalists and linguistic analysts stress. Thus intelligibility and explanatory power, and not just observableness or predictive success, is a guide to the real.

Turning to philosophy of religion, Barbour constructed a similar defense of critical realism. Here his sources in religious epistemology, methodology and language include the writings of John Wisdom, John Hick, Ian Ramsey and Frederick Ferré.With these arguments in place, Barbour was prepared to make his crucial, ‘bridging’ methodological claim: “the basic structure of religion is similar to that of science in some respects, though it differs at several crucial points.”Similarities: Both science and religion make cognitive claims about the world using a hypothetico-deductive method and a contextualist and historicist framework. Both communities organize observation and experience through models seen as analogical, extensible, coherent and symbolic, and these models are expressed through metaphors.Differences. But there are important differences in the ‘data’ of religion compared to that of science.Religious models serve non-cognitive functions which are missing in science, such as eliciting attitudes, personal involvement and transformation. Moreover, compared to science, where theories tend to dominate models, in religion models are more influential than theories.Religion lacks lower-level laws such as those found in science, and the emergence of consensus seems “an unrealizable goal.” Religion also includes elements not found in science such as story, ritual, and revelation through historical events.

Barbour’s argument culminates in his use of paradigm analysis to place science and religion on a continuous spectrum in which both display ‘subjective’ as well as ‘objective’ features, though the former are more prominent in religion and the latter in science.The subjective features include “the influence of theory on data, the resistance of comprehensive theories to falsification, and the absence of rules for choice among paradigms.”Objective features include “the presence of common data on which disputants can agree, the cumulative effect of evidence for or against a theory, and the existence of criteria which are not paradigm-dependent.” It is the dynamic tension between similarities and differences, and between subjective and objective features in both science and religion, that together make Barbour’s analysis so original and fruitful.

Yet even while Barbour was developing this position, scientific realism was being challenged in a number of ways.Though Kuhn had focused primarily on factors internal to the scientific community, sociologists from the 1970s on explored the social construction of science. These externalist accounts of science emphasized the social history of science and the variety of political and economic influences on science. According to one school (the “strong program”), the theory-ladenness of data and the underdetermination of theories by evidence heavily influence the formation and content of scientific theories and the ways they are assessed. At the same time, Marxists argued that science is a source of power over nature and thus over people, power rationalized by appeals to the myth of objectivity. Meanwhile the diversity of philosophical views on realism in science was growing, along with an increasing number of anti-realist positions. Realists frequently argued that social and personal influences are gradually filtered out by the methods of testing used in the sciences. Moreover, the increasing success in predictive power and technological application implies that scientific knowledge is referential.Barbour’s recent assessment is that these externalist accounts provide a “valuable corrective” to the internalist view, particularly regarding the context of discovery. However, the appeal to interests is hard to document and it underestimates the constraints on theories by data and the fact that the testing of theories reduces distortions due to ideologies and interests. Finally, the charge of cultural relativism should apply to the externalist claim as well.

Barbour’s arguments have been developed in significant and diverse ways by a variety of scholars. In his 1979 Bampton Lecturesand in his 1983 Mendenhall Lectures,Arthur Peacocke endorsed critical realism in both science and religion. In science, where challenges to realism from sociologists of knowledge were mounting, Peacocke draw on arguments for realism by Ernan McMullin, Hilary Putnam and Ian Hacking.In his 1993 Gifford Lectures, Peacocke acknowledged the diversity of positions held by scientific realistsbut argued for a “common core” of claims: that scientific change is progressive and that the aim of science is to depict reality. Peacocke made a similar case for critical realism in theology, where the social conditioning of beliefs is generally assumed. As in science, theological concepts and models are partial, inadequate, and revisable, and, unlike those in science, they include a strong, affective function. Still Peacocke views them as “(the) necessary and, indeed, the only ways of referring to ‘God’ and to God’s relation with humanity”, though he stresses that referring to God (e.g., the via positiva) does not mean describing God (the via negativa).Its grounding in a continuous community and interpretive tradition make it “reasonable” to accept theology’s explication of religious experience, though metaphorical and revisable, as an inference to the best explanation.

Other scholars in theology and science have taken similar approaches. According to John Polkinghorne, critical realism is the best explanation of the success of science, the only philosophy adequate to scientific experience, and the view most congenial to scientists themselves. In his 1994 Gifford Lectures, Polkinghorne drew on Thomas Torrance and Polanyi in highlight the doubly circular character of knowledge: belief and understanding are mutually entailing, and what is known and the knowledge of it are mutually conforming. Scientific theories are shaped by the way things are, offering an ever increasing degree of verisimilitude as suggested by his motto, “epistemology models ontology.”Polkinghorne offers similar arguments for theology, too. “(F)rom a theological perspective, all forms of realism are divinely underwritten, for God will not mislead us...”. Wentzel van Huyssteen, in his earlier writings, also viewed theology from a realist perspective, claiming that “theology ... is scientifically committed to a realist point of view” and describing the referential power of theological language about God as “reality depiction.” For van Huyssteen, the hypothetical status of scientific statements become the eschatological dimension of theological statements.Thomas F. Torrance, too, argues for the scientific character of theology because, like the natural sciences, it adopts a method which is determined by its object. For theology, the object is God, known to us by God’s revelation in the incarnation and resurrection of the Word. Thus the theoretical structures of theology disclose knowledge of God just as the theoretical structures in science, like Einstein’s general relativity, provide objective knowledge of this world. According to Torrance, natural theology can find a place within positive theology, though not as a prolegomenon to it --- a view which he reports he persuaded Karl Barth eventually to accept.

The central role Barbour gave to metaphors, models and paradigms in both science and theology has stimulated wide discussion, too. In 1982, Sallie McFague drew directly from Barbour’s workin pointing to basic similarities between models in theology and in science, but she also stressed four important differences: they provide order in theology while stimulating new discoveries in science; they more clearly carry meaning in theology than in science; and unlike in science, they are ubiquitous and hierarchical, as well as eliciting feelings and action, in theology.McFague combined this with Paul Ricoeur’s notion of metaphor as “is and is not” in developing what she then termed “metaphorical theology”. Using this approach she has developed new metaphors for God as Mother, Lover, and Friend, and the world as the body of God which challenge theology’s patriarchical and androcentric distortions and fund her work in ecological theology. In 1984, Mary Gerhart and Allan Russellcontrasted two meanings of analogy: 1) as an extension of our conceptual network from a known to an unknown and 2) as a new and dynamic relation between two separate networks which distorts both and induces tension. They call the latter ‘metaphor, concluding that the relation between science and religion is itself a metaphor.In 1985 Janet Soskicepublished a thorough study of metaphor in religious and scientific language, emphasizing the distinction between metaphor and model which she found conflated in Black, Barbour, Ferré and David Tracy.Although she vigorously defended theological realism, Soskice also stressed the social and contextual nature of scientific realism, in which theoretical terms “ are seen as representing reality without claiming to be representationally privileged.” Theological realism, in turn, distinguishes between referring to God and defining “God”, and employs a causal theory of reference.In 1988, Hans Küng applied paradigm analysis to the history of theology and compared the results to the history of science.In contrast to the way paradigms are successively replaced in science, giving it an irreversible history, in theology contrasting paradigms, such as Thomism, Reformation theology, modernity, may well coexist in history. In science the next revolution comes at the limits of the existing paradigm. In theology the ‘primal testimony’ of scripture and the events of the history of Israel and Jesus Christ are the sources of each new revolution.

An important development has been the theme of “consonance” introduced in 1981 by Ernan McMullin. His concern was the search for a “coherence of world-view” to which all forms of human knowing can contribute. The consonance that characterizes such a world-view does not require or even expect direct support.Instead it would involve mutual contributions in a relation that is tentative and open to “constant slight shift”. Beginning in 1989, I combined McMullin’s idea with McFague’s epistemic claim about the “is and is not” structure of metaphor to include and thus to learn from both consonance and “dissonance” between scientific and theological theories. Rather than undercutting a coherent world-view, dissonance points to the dynamic character of our world view, specifying where problems arise, shifts are required, and potentially greater coherence can be sought. Moreover, by recognizing that theories in both science and theology evolve and are eventually replaced, we can build change directly into the relation between science and theology rather than being threatened by it.

Over the past decade, Ted Peters has developed this approach in terms of what he calls “hypothetical consonance.”If consonance in the ‘strong sense’ means complete harmony or accord, we might “hope to find (it), but we have not found it yet.” What we do have are shared domains of inquiry or consonance in a ‘weak sense,’ but this is enough to encourage further exploration. He bases this on his critical realist assumption that theologians and scientists are seeking to understand the same reality.The qualifier ‘hypothetical’ reminds theologians to treat their assertions as fallible and subject to possible disconfirmation as well as confirmation. Willem B. Drees, though exploring the concept of consonance, has pointed out the problemmatic assumptions underlying realism and a correspondence theory of truth. Instead he proposes “constructing a consonance world” which includes God’s otherness and the prophetic challenge of lived values.Our religious traditions invite us to wander through, and our sciences to wonder about, the reality which transcends and sustains our lives and to engage ethically with the challenge of the future.

Contributed by: Dr. Robert Russell