"NORMAL" SCIENCE BEING INDEPENDENT OF THEORY:

In 1962, Thomas Kuhn wrote his ground-breaking book The Structure of Scientific Revolutions, in which he argues that scientific consensus is not neutral and disinterested, but emerges out of paradigms held by factions and in-groups devoted to their own survival. It is, hands down, the single most influential work of philosophy of science in the last century.  It's core message, however, has not filtered down to popular culture, because questioning the disinterested status of science is, peripherally, to question the disinterested neutrality of liberal nation states.    

Kuhn begins by thinking about the textbooks from which we all learn about science and how they form our minds.  He worries that the image of science they present is as glossed over as a tourist brochure.[1]  Textbooks tend to praise the achievements of great lone scientists and downplay science as a communal, cultural enterprise.  Perhaps most perniciously, because of their aim of getting novices up to speed so that they can understand (and even practice in) today's scientific landscape, they select episodes in the history of science and arrange them in a seamless narrative all leading to...us, scientific modernity.  Inevitably, this has the effect of confirming our positivist prejudices; it makes science look like a straight line of progress, only opposed by the forces of superstition.

If you look at the actual revolutions of thought in the history of science, Kuhn argues, this isn't what you'll see.  Science is done by real human beings.  Its history is a history of fights between groups of scientists not only over particular facts but over method and what counts as science at all.  By uncovering the personal and social dimensions of science, Kuhn ushered in the "historical" or "sociological" turn in philosophy of science.  

Kuhn's historical studies paint a far more nuanced and interesting picture of science.  Its history is more than the history of ideas; it is also a history of real people, with all their flaws and foibles.  There is more to science than facts simply presenting themselves to great minds.  It is a history of genius and innovation, sure.  But it is also a history of cliques, defending theories despite counter-evidence, and dead ends.  But these never make it into the textbooks, both because it would undermine the progressive, positivist narrative that is meant to attract new scientists to the discipline, and also because stories of dead ends don't help students learn current scientific theories.  Any history that includes successes but never failures is bound to look linear and progressive.[2]  Yet the effect, Kuhn thinks, is a picture of science that is pure science fiction.

According to Kuhn, most science--what he calls "normal science"--is not revolutionary.  That is, it doesn't set out to answer groundbreaking questions but to slightly extend our knowledge in some very limited domain.  Normal science doesn't question its foundations but, rather, works within a paradigm or large set of settled assumptions about its subject matter.[3]  Now, paradigms can sound very negative, because their job is to be settled and dogmatic, to force us to view nature in preconceived categories and rigidly indoctrinate students.  And this is indeed a major lesson of Kuhn's work.  However, the advantage of paradigms is that the scientist doesn't have to constantly justify her basic outlook but can treat some things as settled and dive deeper into nature on those assumptions.  Kuhn likens it to a settled judicial decision.[4]  In this way, real but limited progress is made.

But there are also periods of science where there is a sense of unease and dissatisfaction with the reigning paradigm.  Kuhn especially has in mind the growing unease with the increasingly baroque Ptolemaic model of the solar system.  In these revolutionary periods, fundamental assumptions are challenged.  

Importantly, this is not a dispassionate process by which the evidence is obvious to all and the best theory automatically wins out.  Kuhn's historical study revealed that new paradigms are created not by seasoned veterans of the field but by the young or those new to the field who haven't had their minds ossified by years of thinking in the old paradigm.[5]  Instead of convincing the old guard, advocates of the new paradigm simply attract more young scientists to their research program (e.g., they attract more graduate students with an exciting new way of thinking).  

And the minute the new paradigm wins out, say, the Copernican model, its rivals are ridiculed as "non-scientific."  The old guard is shunned, their work ignored.[6]  The revolution does not take place because the old guard become convinced by overwhelming evidence, see the light, and recant. (That is to say, the scientists do not actually behave scientifically, disinterestedly following the evidence wherever it leads.)  Rather, the revolution happens when they die off.  The historical record, he argues, challenges the positivist narrative of science as uniquely rational and automatically progressive.  Science isn't populated by Spock-like, neutral, open-minded observers following the evidence wherever it leads.  It is populated by actual humans.

Darwin's theory of evolution offers a sweeping explanation of the history of life, from the earliest microscopic organisms billions of years ago to all the plants and animals around us today. Much of the evidence that might have established the theory on an unshakable empirical foundation, however, remains lost in the distant past. For instance, Darwin hoped we would discover transitional precursors to the animal forms that appear abruptly in the Cambrian strata. Since then we have found many ancient fossils – even exquisitely preserved soft-bodied creatures – but none are credible ancestors to the Cambrian animals.

Despite this and other difficulties, the modern form of Darwin's theory has been raised to its present high status because it's said to be the cornerstone of modern experimental biology. But is that correct? "While the great majority of biologists would probably agree with Theodosius Dobzhansky's dictum that 'nothing in biology makes sense except in the light of evolution,' most can conduct their work quite happily without particular reference to evolutionary ideas," A.S. Wilkins, editor of the journal BioEssays, wrote in 2000 "Evolution would appear to be the indispensable unifying idea and, at the same time, a highly superfluous one."

I would tend to agree. Certainly, my own research with antibiotics during World War II received no guidance from insights provided by Darwinian evolution. Nor did Alexander Fleming's discovery of bacterial inhibition by penicillin. I recently asked more than 70 eminent researchers if they would have done their work differently if they had thought Darwin's theory was wrong. The responses were all the same: No.

I also examined the outstanding biodiscoveries of the past century: the discovery of the double helix; the characterization of the ribosome; the mapping of genomes; research on medications and drug reactions; improvements in food production and sanitation; the development of new surgeries; and others. I even queried biologists working in areas where one would expect the Darwinian paradigm to have most benefited research, such as the emergence of resistance to antibiotics and pesticides. Here, as elsewhere, I found that Darwin's theory had provided no discernible guidance, but was brought in, after the breakthroughs, as an interesting narrative gloss.

In the peer-reviewed literature, the word "evolution" often occurs as a sort of coda to academic papers in experimental biology. Is the term integral or superfluous to the substance of these papers? To find out, I substituted for "evolution" some other word – "Buddhism," "Aztec cosmology," or even "creationism." I found that the substitution never touched the paper's core. This did not surprise me. From my conversations with leading researchers it had became clear that modern experimental biology gains its strength from the availability of new instruments and methodologies, not from an immersion in historical biology.

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