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Metaphorical Thinking

Robert Root-Bernstein

Making Truth: Metaphor in Science. Theodore L. Brown. xiv + 215 pp. University of Illinois Press, 2003. $32.50.

Theodore Brown has seen the light. There is no other way to describe his conversion to the kind of metaphorical thinking he describes in Making Truth: Metaphor in Science. Joining his new sect, however, requires philosophical commitments that many readers may be unwilling to make.

Few scientists will be surprised by Brown's thesis that metaphors are rampant in science. Astrophysicists have described the distribution of mass in the universe as foamlike; chemists still ascribe orbitals to atoms as if electrons were planets spinning around a nuclear sun; biologists have their genetic code; environmentalists sometimes describe the Earth as if it were a living organism. Brown himself illustrates in detail the uses of metaphors to describe the classical atom, the quantum atom, molecular models, protein folding, concepts of cells and global warming. He leaves us in no doubt that we all use metaphors. The question that will divide readers is how important such metaphors are to actually doing and thinking about science.

The difficulties begin with Brown's definition of metaphor. Most people use the term to denote a figure of speech that suggests a similarity between two nonidentical things. For example, the atom has been characterized as "a miniature solar system." The energy in electrons can be said to be quantized in the same way that modes of a vibrating string are quantized. The atmosphere is described as trapping heat from the Sun, just as a greenhouse does. We use concepts we already understand as bridges to comprehend phenomena that are still mysterious.

Brown casts his net much wider, using the phrase conceptual metaphor to mean any nonliteral use of language that results in a partial mapping of one term, image, object, concept or process onto another to reveal unsuspected similarities. At various places in the book the phrase encompasses the terms similarity, metaphor, analogy, abstraction, model, illustration, figure, hypothesis, theory and even mathematics, as well as literary terms such as simile, irony, trope, metonymy, and synecdoche. Brown asserts, for example, that observational data "can be related to models only through metaphors for interpreting the data." He also says that "Molecular models are metaphors because they represent a mapping from the domain of pictorial or three-dimensional model representation onto the domain of data from X ray diffraction and other experimental observations."

Concepts are metaphorical as well: "Heat is a metaphorical construct," he says; "there is no observable entity, fluid or otherwise, observed in the process by which two bodies [in contact] come to a common temperature." Also, in his view global temperature is metaphorical, because "there is no literal temperature of the planet." Brown even asserts that "mathematical descriptions are themselves metaphors. . . . They are another form of what might be said verbally or diagrammed." He is so consumed with finding unity in diversity that he fails to realize that when a single concept becomes so broad that it encompasses everything, it becomes useless.

Brown, an emeritus professor of chemistry at the University of Illinois at Urbana-Champaign, admits that he is an acolyte of cognitive linguist George P. Lakoff and is preaching his embodied realism, a philosophy that asserts the existence of a "reality" independent of human beings, which we are unable to know directly because our sensorium limits and distorts our perceptions. Thus "Embodied realism denies that there is a single absolutely correct description of the world." All that we think we know is metaphorical. Scientists reach general consensus on some principles only because all human beings share a common set of metaphors based on their common body plan and senses.

Lakoff and Mark Johnson first enunciated this philosophy in their 1980 book Metaphors We Live By and further developed it in their 1999 book Philosophy of the Flesh; Lakoff also pursued it with Rafael Núnez in Where Mathematics Comes From (2000). These books present three basic principles, which Brown quotes and elaborates on: "The mind is inherently embodied. Thought is mostly unconscious. Abstract concepts are largely metaphorical." If you know and like Lakoff's philosophy, you'll probably understand and like Brown's book. If you haven't read or don't like Lakoff's work, then you are likely to find Brown confusing and perhaps confused.

One of the greatest failings of Making Truth is that the philosophical propositions underlying the narrative are trotted out as if they are self-obvious. Their consequences are never discussed. Brown seems unaware that cultures use different kinds of metaphors that make idiomatic translations impossible. How do language differences influence science and truth for the embodied realist? Can a deaf-blind person or a congenital quadriplegic participate in embodied science developed mainly by hearing, sighted, fully mobile people? Would aliens with different body plans and sensory capabilities develop a science incompatible with ours? Brown's failure to explore such questions leaves us at a loss to understand how metaphors mediate the relationship of his "truth" to his "embodied reality." Equally disturbing is that, save for the chapter on global warming, one gets no sense of the ways metaphors fail or mislead. This is a point that Lakoff and all his followers need to address.

The most disappointing aspect of Brown's book, regardless of one's take on his philosophy, is his apparent ignorance of the vast literature on metaphorical thinking by historians of science and scientists themselves—for example, Agnes Arber's The Mind and the Eye (1954); Jacob Bronowski's Science and Human Values (1956); Rom Harré's The Principles of Scientific Thinking (1970); Donna Haraway's Crystals, Fabrics, and Fields (1976); Nigel Gilbert and Michael Mulkay's Opening Pandora's Box (1984); Mae-Wan Ho and Sidney Fox's Evolutionary Processes and Metaphors (1988); Emily Martin's Flexible Bodies [a look at metaphorical thinking in immunology and AIDS] (1994); Evelyn Fox Keller's Refiguring Life (1995); and my own Sparks of Genius (1999). Brown cites none of these, nor does he refer to the many relevant articles that can be found in publications such as the Journal of Chemical Education or HYLE, the international journal for philosophy of chemistry.

Let me be clear: Metaphors are essential to doing and teaching science. In fact, Isaac Asimov once opined that teaching is the art of analogy. But anyone using metaphors or writing about them should always remember Arturo Rosenblueth and Norbert Wiener's warning: "The price of metaphor is eternal vigilance."—Robert Root-Bernstein, Physiology, Michigan State University, East Lansing

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