Helmholtz: From Enlightenment to Neuroscience
Helmholtz: From Enlightenment to Neuroscience
by Michel Meulders; edited and translated by Laurence Garey
The MIT Press, Cambridge, MA, 2010
264 pp., illus. 32 b/w. Trade, $27.95/£19.95
Reviewed by Amy Ione
Director, The Diatrope Institute
Berkeley, CA 94704 USA
A recurring topic among those interested in art, science, and technology is the value of transdisciplinary approaches. In my view, those who gravitate to this area (or related areas such as interdisciplinary, multidisciplinary, and integrative studies) see broad-based thinking both as a creative tool and a means to innovatively address some of the complex issues of our world today. Among these people are some who value disciplinary boundaries and believe that those who can operationally span their narrow parameters have the best foundation for conceptualizing how to innovate and see beyond known territory. The tendency to cast Leonardo da Vinci in the role of the “historical archetype” of this type of person, the “Renaissance Man,” has perhaps allowed us to lose sight of the many other original thinkers who exemplify what creative minds can accomplish when paired with a far-ranging, inventive imagination.
Helmholtz: From Enlightenment to Neuroscience by Michel Meulders offers a reminder that we can identify a number of figures in the past who worked across disciplines. The book introduces us to Hermann von Helmholtz (1821–1894), trained by Johannes Müller, and one of the most accomplished physiologists of his time. A key nineteenth century polymath, Helmholtz used a versatile toolbox for his co-discovery of the principle of the conservation of energy, his invention of several instruments (e.g. the ophthalmoscope, the ophthalmometer and the telestereoscope), and his many significant contributions to physics, physiology, physical theory, philosophy of science and mathematics, and aesthetic thought.
How Helmholtz brought his varied interests and education into his laboratory is one thread that runs through the book. We learn that during his formative years he was exposed to philosophy and strongly influenced by his father, a German teacher who cultivated an interest in science and philosophy. Although Hermann was strongly attracted to the natural sciences, his father urged him toward medicine because funding for medical education was available. After training in physiology, Helmholtz worked in many areas outside of medicine over the years. Indeed, a defining feature of Helmholtz’s work was the way he branched out in many fields as he sought to translate his biological insights through an empirical and mathematical framework. In this, he was aided by his keen observational abilities and his passion for experimentation.
I began this book expecting a biography that would offer a chronology of Helmholtz’ work, along with contextual material to help the reader place his work within the nineteenth century world. The author instead offers a quite variegated picture that made it somewhat difficult for me to see the man as a whole as I read. The challenge in ferreting out Helmholtz’ story was due to the amount of material the author included that contextualizes Helmholtz in terms of the people and ideas that influenced him. For example, the chapter on “Goethe and His Vision of Nature” is 13 pages and does not mention Helmholtz. It seems its purpose is to provide a framework for where Helmholtz’ views of color differ from those of Goethe, which is discussed eight pages into the next chapter. Long “asides” such as this are quite distracting and make it difficult to understand what the author wanted the reader to take away from the book. What was clear is that the author has great enthusiasm for the accomplishments of Helmholtz. In addition to the Goethe chapter, there are chapters on “Johannes Müller: “Man of Iron” and “Conclusion: The Wisdom of Alexander von Humboldt.” It is hard to say if this format was intentional or if the chapters began as stand alone articles and were later pieced together into this book.
The strongest chapters are the two that cover Helmholtz’ work on hearing and acoustics and the one chapter that summarizes Helmholtz’s theory of visual perception. Helmholtz’s introduction in his Sensations of Tone as a Physiological Basis for the Theory of Music says that this work aimed to bring together work in physical and physiological acoustics, music and aesthetics that had remained unreasonably far apart. The author explains that Helmholtz’s early musical education and cultivation of musical activities throughout his life provided a foundation as well as a motivation for the experiments with sound. We also learn that this scientist invented the “Helmholtz resonator” to identify the various frequencies or "tones" present in musical chords and other sounds containing by multiple tones. The bell was among the instruments Helmholtz studied. His attraction to this instrument says quite a bit about he approached his work overall. Helmholtz was drawn to the bell because it is difficult to cast a good bell, for one needs to obtain an equal thickness around the whole circumference. If the thickness is different at two different places, there is a spot on the edge of the bell that vibrates to give a certain tone, while the neighboring spot produces a different tone and the intermediate zone between the two produced both tones at the same time. Helmholtz wanted to understand the unpleasant dissonance of this phenomenon. Ultimately, he demonstrated that difference and combination (or sum) tones existed objectively, outside the ear. (Although, ironically, bells are characterized by anharmonic relationships among their tones, but they still sound good.)
Another disappointment with the presentation was that the captions for a number of illustrations were far too abbreviated. Many basically said what the image is and provided virtually no information about how the depicted equipment (or whatever) works. Because this was not always the case, particularly in the chapter on music where the captions were full-bodied descriptions, the captions, too, led me to wonder if the chapters were originally written as stand-alone articles.
All in all, once I adjusted to the book “as a collage” and absorbed it on its own terms, I found it an informative read. It developed Helmholtz sufficiently to send me looking for more details. When I read further, I realized that all the basics were covered. It was only because the book covered the territory in an unusual fashion that it was harder for me to see the geography, so to speak.
Finally, based on the title of the book, Helmholtz: From Enlightenment to Neuroscience, I thought I would find many references to contemporary neuroscience. This was not the case. Basically, at the end the book acknowledges Helmholtz’s contributions to contemporary investigations, saying:
“Neuroscience and cognitive science, as we call them today, owe numerous research domains to [Helmholtz}, as well as attitudes. No phenomenon of nature, life, or environment left his encyclopedic mind indifferent. He believed he could reconcile science and philosophy, notably by thinking that Kant’s a priori had in the last resort a physiological basis that would one day doubtless be discovered.” (p. 215)
Personally, I think adding more specifics to this comment would have offered the contemporary reader a better grasp of Helmholtz’s accomplishments than the chapter on Goethe. For example, there is much one can say about Helmholtz’s color theory. As Meulders points out, Helmholtz modified Thomas Young’s trichromatic (three-color) theory, which is based on the idea that the eye responds to three primary colors. It is an additive color mixing theory and predicted the existence of three classes of color-sensitive cone receptors. What it does not explain are afterimages. A contemporary, Ewald Hering, who was more of a phenomenologist, took issue with the trichromatic theory based on the existence of color afterimages. Hering proposed an opponent process theory of two pairs of opposites across the color circle. He also held that both theories could be equally valid. We now know that Hering was correct in seeing compatibility between the two theories. What Meulders does not really discuss is that science today allows that there are different levels of visual processing, corresponding to the two theoretical approaches. Thus, to some degree, both Helmholtz and Hering were correct in principle, although wrong as to some of the details.
In closing, even though there was a lot to like about this book. Those seeking a biography of Helmholtz may want to start with the excellent contemporary biography by Helmholtz’s friend and associate, the mathematician Leo Königsberger (which is available in full on Google Books ). Unfortunately, as I noted, Meulders’ book does not attempt to update the science relating to Helmholtz’s work, and the Königsberger book is out-of-date scientifically. Some more recent collections that I found were are also useful in pulling the threads together, particularly David Cahan’s Hermann von Helmholtz and the foundations of nineteenth-century science .
 Königsberger, Leo. 1906. Hermann von Helmholtz. Clarendon Press. Hermann von Helmholtz by Leo Königsberger is available at http://books.google.com/books?id=JCNWAAAAMAAJ&dq=helmholtz&pg=PP3#v=onepage&q&f=false.
Cahan, David, ed. 1993. Hermann von Helmholtz and the foundations of nineteenth-century science. University of California Press.