One question that has almost disappeared, but which I think should not is the old question about whether our categories of reality are discovered or constructed. In medieval times this was the debate about realism versus nominalism. Earlier this century the question flared up again in the debates about the relativistic nature of knowledge and has more recently given rise to the whole "science wars" debacle, but reading the science press today one would think the question had been finally resolved — on the side of realism. Reading the science press now one gets a strong impression that for most scientists our categories of reality are Platonic, almost God-given entities just waiting for the right mind to uncover them. This hard-nosed realist trend is evident across the spectrum of the sciences, but is particularly strong in physics, where the search is currently on for the supposed "ultimate" category of reality — strings being a favored candidate. What gets lost in all this is any analysis of the role that language plays in our pictures of reality. We literally cannot see things that we have no words for. As Einstein once said "we can only see what our theories allow us to see." I would argue that the question of what role language plays in shaping our picture of reality is one of the most critical questions in science today — and one that should be back on the agenda of every thoughtful scientiist.
Just one example should suffice to illustrate what is at stake here: MIT philosopher of science Evelyn Fox Keller has shown in her book Secrets of Life, Secrets of Death (and elsewhere) the primary role played by language in shaping theories of genetics. Earlier this century physicists like Max Delbruck and Erwin Schrodinger started to have a philosophical impact on the biological sciences, which henceforth became increasingly "physicized." Just as atoms were seen as the ultimate constituents of matter so genes came to be seen as the ultimate constituents of life — the entities in which all power and control over living organisms resided. What this metaphor of the "master molecule" obscured was th role played by the cytoplasm in regulating the function and activation of genes. For half a century study of the cytoplasm was virtually ignored because genetics were so fixed on the idea of the gene as the "master colecule." Sure much good work on genetics was done, but important areas of biological function were also ignored. And are still being ignored by the current "master molecule" camp — the evolutionary psychologists, who cannot seem to see anything but through the prism of genes.
Scientists (like all other humans) can only see reality as their language and their metaphors allow them to see it. This is not to say that scientists "make up" their discoveries, only to point out that language plays a critical role in shaping the way we categorize, and hence theorize, the world around us. Revolutions in science are not just the result of revolutions in the laboratory or at theorists blackboards, they are also linguistic revoluttions. Think of words like inertia, energy, momentum — words which did not have any scientific meaning before the seventeenth century. Or words like quantum, spin, charm and strange, which have only had scientific meaning science the quantum revolution of the early twentieth century. Categories of reality are not merely discovered — they are also constructed by the words we use. Understanding more deeply the interplay between the physical world and human language is, I believe, one of the major tasks for the future of science.
MARGARET WERTHEIM is the author of Pythagoras Trousers, a history of the relationship between physics and religion; and The Pearly Gates of Cyberspace: A History of Space from Dante to the Internet. She is a research associate to the American Museum of Natural History in NY and a fellow of the Los Angeles Institute for the Humanities. She is currently working on a documentary about "outsider physics."