While his professional work is primarily in elementary particle physics, Steven Weinberg became widely known to the general public with the publication of a book on cosmology, The First Three Minutes (1977), which presented a lucid and fascinating story of the early development of the universe with style and elegance. His new book, Facing Up: Science and Its Cultural Adversaries, which consists of a collection of twenty-three equally well-written essays, documents the personal commitment of the author to promoting and defending his scientific views. Weinberg captures the interest of his readers by combining balanced judgments and modest claims about current scientific theory with a passionate defense of reductionism.
While Weinberg defends reductionism, he is careful to distinguish it both from what he calls “positivism,” which he understands to be a narrow empiricism, and from “petty reductionism,” which seeks to reduce everything to elementary particles. The reductionism Weinberg advocates is the program of reductive explanation of physical phenomena by recourse to ever more fundamental and simple laws that are supposed to account for the unity of the universe. He shows that this was already Newton’s vision and continued to be the driving force behind the great theories of the last century, those of General Relativity and the standard quantum field theory. Going further, he predicts that such reductionism will one day produce a “final” theory that can account for the unity of the universe.
Up to this point, Weinberg’s defense of reductionism makes considerable sense. Yet the question remains as to whether explanation by laws provides the only or the ultimate explanation for the unity of the universe. The concept of law involves abstraction from particularities, but those particularities have to be taken into consideration when those laws are applied to the course of natural events. With regard to the history of the universe, Weinberg himself speaks of “historical contingencies” in the history of the solar system and in the development of life. He also acknowledges the idea of an “emergence” of forms of higher organization from increasingly complicated systems. But doesn’t that suggest that the unity of the universe is finally a unity of history, which is different from the generality of laws? And history is always a sequence of contingent events, regardless of the laws that may prevail within the flow of those events. Perhaps, then, the modesty of the scientist might properly be applied to his larger project of subsuming the universe as a whole under a universal concept of law. Such a modest approach might have to give up the quest for the ultimate and most comprehensive description of the nature of the universe. But it would make room for some additional, philosophical reflection on the reality of nature.
One of the most important contributions of Weinberg’s book is his ongoing argument against the “social constructionists” who question the truth claims of science. This is an issue of very general importance, far beyond the philosophy of science. With every assertive sentence, we raise truth claims that cannot be reduced to social conventions. Science is only a particularly obvious case. Weinberg acknowledges the influence of social and cultural conditions in the history of science. But these influences do not weaken the truth claims of scientific theories. The same is true of any other truth claims we raise in everyday life or in other fields of culture. The “realism” of science, which Weinberg advocates, might serve as an example and antidote against the excesses of postmodernism.
The “cultural adversaries” of science to whom Weinberg refers in his title are those social constructionists who tend to relativize the truth claims of scientific theories. But even worse than these academic theorists would be an alliance between the “antiscientific intelligentsia inside the universities” and “the enormous force of religious belief.” Here, apparently, he has in mind the religious fundamentalism of the creationists. But could such an alliance pose a real threat to the cultural acceptance of science? Is not science pampered by the political establishment in Western societies like no other intellectual discipline? Among the general public, scientists are highly regarded, and most religious people share in that positive appreciation of science, since they do not believe that science and religion are opposed to one another.
While in the course of modern history there have been occasions when science has opposed religious teaching as well as other traditional ways of looking at the world, the most creative scientists have far more often been motivated by religious inspiration. Moreover, Christian theologians and churchmen have frequently and gratefully received the new perspectives offered by scientific discoveries. This is true even in the case of Darwinism, which was one of a number of evolutionary theories proposed in the nineteenth century, many of which arose from religious reflection. At the present moment, when the number of institutions that seek to foster dialogue between religion and science continues to grow, most religious people view science as a positive pursuit that at the deepest level harmonizes with their faith.
In fact, such a positive attitude is arguably easier to maintain at the present moment than it was in earlier centuries, since Big Bang cosmology removes the apparent contradiction between the biblical doctrine of creation and the belief in a temporal and spatial infinity of the world that had been taken for granted during two centuries of scientific exploration. Of course, the assumption of an origin of the universe at some finite point in the past does not “prove” the biblical doctrine of creation, but it is “consonant” with it, to invoke the useful term of Ernan McMullin.
The same applies to the idea of God as creator. Weinberg takes a skeptical position on this matter, and some of his arguments are not without plausibility. He dealt with this issue more extensively in his earlier book Dreams of a Final Theoryý(1993), in which he devoted an entire chapter to “the question of God.” Even a Christian theologian can share Weinberg’s reservations concerning the stronger versions of the anthropic principle and the related idea of a “designer God.” The idea of a designer sounds rather anthropomorphic, and it is often presented in forms that are hardly consonant with God’s infinity and eternity. In the Bible, the contingency of finite reality, of each event and even of the world as a whole, including the element of order within it, is far more important in expressing its dependence upon God the creator.
Weinberg has little to say on this issue, which is decisive for those who maintain the rationality of belief in a creator God. The element of design enters the picture only as an implication that follows from the act of creation and God’s ongoing relation to the universe as a whole—a whole within which every part has its proper place. Of course, such a view culminates in the problems of theodicy, and here the Christian has to join Weinberg in affirming that all of our knowledge is approximation, even our theology. Not until the eschatological consummation of history will we know even as we are known by God (1 Corinthians 13:12).
Wolfhart Pannenberg is Professor Emeritus of Systematic Theology at the University of Munich and founding director of the Institute of Ecumenical Theology.