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What Makes Science Successful?

Margaret Jacob

The Intelligibility of Nature: How Science Makes Sense of the World. Peter Dear. xii + 242 pp. University of Chicago Press, 2006. $27.50.

In The Intelligibility of Nature, Peter Dear explores two aspects of science: its concern with explaining and understanding the natural world (science as natural philosophy), and its claim to practical efficacy (science as engineering or manipulation). To illustrate these aspects, the book surveys a few high points in the history of science from Newton to the present. It begins with a brief nod to Aristotle, pointing out that he (and his followers over the centuries) understood natural processes to be "directed towards a goal." Dear then jumps forward to modern science, which began in the 17th century by repudiating Aristotle's teleology. Toward the end of the book, he tells us that, ironically, in modern biology "teleological explanation remains alive and well. . . . The only difference is that God is not invoked; natural selection plays the same role." In Dear's accounting, the displacement of words by other words ("God" by "natural selection," for example) is one key to unlocking the rhetoric employed by science to explain the natural world.

How does science manage both to make nature intelligible and to make us believe in its own effectiveness? Dear sees as crucial the complex interplay of theory (natural philosophy) and its handmaiden, instrumentality (the aim of creating material control over nature). Sometimes theory holds sway. Against all doubters, both Newton and Lavoisier argued that their respective theories, backed by quantitative work, should be sufficient to account for phenomena. Armored by theory, their versions of science eventually came to dominate. Other, less audacious, 18th-century practitioners of taxonomy, natural history, botany and astronomy relied less on natural philosophy and more on classification—on empirical observing and cataloguing.

In the mid-19th century, with the arrival of natural selection as a concept, natural philosophy returned in full force. Later, Einstein opted for intuition and thought experiments. His ultimate goal was to ensure a natural-philosophical physics that could "speak about a world that existed independently of the human observer," whereas his rival Bohr wanted a "scientific truth that was relative to the nature of human cognition" and, of course, experimentation. Indebted to their theorists, both modern cosmology and evolutionary biology grant natural philosophy "intellectual priority over efficacy."

An interrogation of how knowledge accumulates and acquires validity over time lies at the heart of any critical examination of the success of science, or of any discipline, for that matter. Most critics would begin their analysis of the knowledge claims made with a set of questions more inclusive than those Dear brings to his investigation of the prestige of the natural sciences. In his analysis, only two elements count: natural-philosophical positions and claims about instrumentality—that is, theories and efficacy, which conspire and interweave:

Why are science's instrumental techniques effective? The usual answer is: by virtue of science's (true) natural philosophy. How is science's natural philosophy shown to be true, or at least likely? The answer: by virtue of science's (effective) instrumental capabilities. Such is the belief, amounting to an ideology, by which science is understood in modern culture. It is circular, but invisibly so.

Readers are apparently expected to conclude that, although other disciplines that accumulate knowledge display many factors that explain their relative effectiveness or success, science alone is solely about theories and methods of inquiry. Truth or lesser falsity cannot explain science's success, nor can the replication of experimental methods and results. And the historical circumstances, or context, that may have shaped the science are also irrelevant.

Let's see how this approach works for the history of 17th-century science. Once, when Aristotle held sway, natural philosophy was seen as distantly related to instrumentality and superior to it. Gradually, thanks to Bacon, Descartes and especially Newton, "doing things and understanding things . . . became increasingly folded into one another." The resulting ideas we have today about nature "are all shaped by our acceptance of the images of reality that we owe to science in its guise as natural philosophy." If we assign intelligibility to the world, it is because science has "powerful social authority . . ., which serves to render most people unable to refuse a knowledge-claim presented as a 'scientific fact.'"

In this book, the science that triumphed in early modern Europe did so largely by the rhetorical force that established the intelligibility of its natural philosophy. Dear ignores the enormous difficulties that the Aristotelian doctrine of forms presented by the late 1500s to thinkers from a wide range of philosophical positions. Also absent is any reference to the religious context—to the work that scholasticism (based on a reading of Aristotle) did for Catholic doctrine—or to the historical context, in which English Protestants such as Bacon, Boyle and Newton saw Catholicism associated with royal absolutism as a threat to England's survival as a Protestant nation. Needless to say, Dear does not attribute the success of the new science to what Galileo said he saw with his telescope, or what Boyle observed in the vacuum he thought he had created with his air pump, or what Newton spied with his prisms.

Not examining the historical context allows Dear to claim that when Newton furiously denied the "absurdity" that gravity could be "innate, inherent, and essential to matter," he was trying to save the intelligibility of his natural philosophy. But Newton's actual reason for denouncing that view was different: He was concerned because freethinkers had found ways to use the intelligibility of his natural philosophy as a powerful tool to assert the validity of materialism and pantheism, both of which undercut the Christianity so vital to his life and thought. Failure to see the importance of religious crises—brought about on one hand by the materialism extracted from Newton's science and on the other by the threat of Catholicism—obscures Newton's motives, many of which were shared by his religious contemporaries.

Curiously, when the book gets to Darwin, Dear offers no account of the philosophical underpinning of natural selection. Materialism, which was by then ascendant despite efforts to defeat it, enabled Darwin to imagine vast, even unlimited quantities of time wherein randomness unfolded. But in Dear's account, Darwin relies not so much on an intellectual commitment to natural philosophy as on imagination. Rhetorical and imaginative forces carried the day because "Darwin's natural selection seemed to make sense to those who could imagine its operations with the help of Darwin's often-colorful metaphors."

Dear tells us that "the academic credentials of scientists and the institutions at which they work are important parts of the general credibility of science." Let us apply this claim to his book, just as Dear applies it to science. We may assume that some readers will be convinced of the credibility of his account, not because of his rhetoric and imagination in reducing science solely to the interface of its theories and methods, but because he is a member of the Department of Science and Technology Studies at Cornell University. Others, however, may have more compelling reasons.

Let us imagine one sort of reader who may give credence to Dear's conclusions: a member of a school board in Kansas concerned about the teaching of Darwinian theory. From Dear's book, that school-board member learns that up until the 17th century, most educated Europeans thought that developments in nature "could be understood in terms of processes that aimed at some purpose." Then suddenly the new mechanists challenged those who saw design or purpose in the world, and a natural-philosophical confrontation resulted that "had nothing to do with disagreements over what phenomena there were in the world to be explained." In the ensuing fight, ridicule became the weapon of choice, used to particularly good effect by Descartes. Galileo was also adept at caricature, depicting the Aristotelians as "foolish." Indeed, Dear says, the major mechanists who wish "to convict Aristotelian explanations of failing to make sense" must "pillory them; there is no other recourse."

From reading Dear's book, perhaps the school-board member will come to the following conclusions: Those who ridicule the inclusion of intelligent design in the science curriculum are simply following the tactics that were first inculcated by the founders of the ideology of modern science. The mechanists' rhetorical excesses against design led to the present-day distortions of evolutionary biology. Therefore, teaching intelligent design may be the only way forward in righting a historical wrong and reclaiming for science and posterity the teleological wisdom that once enjoyed intelligibility thanks to Aristotle.

Is this really the kind of history and philosophy of science we want to prevail?

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