Soft Vs. Hard Science, Part I
    By Massimo Pigliucci | May 28th 2008 09:24 AM | 4 comments | Print | E-mail | Track Comments
    About Massimo

    Massimo Pigliucci is Professor of Philosophy at the City University of New York.

    His research focuses on the structure of evolutionary


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    “Scientists these days tend to keep up a polite fiction that all science is equal. Except for the work of the misguided opponent whose arguments we happen to be refuting at the time, we speak as though every scientist's field and methods of study are as good as every other scientist's, and perhaps a little better. This keeps us all cordial when it comes to recommending each other for government grants.” Fighting words about the nature of the scientific enterprise as seen from the inside by a participating scientist. And what makes these sentences even more remarkable is that they were not uttered behind close doors in a room full of smoke, but printed in one of the premiere scientific magazines in the world, Science. It was 1964, the year I was born, and the author was John R. Platt, a biophysicist at the University of Chicago. The debate between scientists on what constitutes “hard” (i.e., good, sound) and “soft” (i.e., bad, sloppy) science has not subsided since.

    Platt was frustrated by the fact that some fields of science seem to make clear and rapid progress, while others keep mucking around without seemingly being able to accomplish much of relevance. As Platt put it, in the same article: “We speak piously of ... making small studies that will add another brick to the temple of science. Most such bricks just lie around the brickyard.” Physics, chemistry and molecular biology are considered by Platt (and many others) as hard sciences, the quintessential model of what science ought to be. Ecology, evolutionary biology, and even more fields like psychology and sociology, are soft sciences, and the maximal aspiration of people working in these fields ought to be to find a way to make them as hard as physics. Platt’s article is a classic that should be read by anyone interested in the nature of science, and he was right in pointing out the problem; he was not quite as right in diagnosing its roots however, and even less so at suggesting a possible cure. Nonetheless, Platt’s critique of soft science provides us with an excellent starting point to explore the idea that, in fact, there may be more than one kind of science, that “science” is a heterogeneous category, a notion that would surprise many in the general public, and that will likely be resisted by most scientists.

    Platt’s attack on soft science begins by stressing the fact that some disciplines seem to make fast and impressive progress, while others have a tendency to go around in circles, or at best move slowly and uncertainly. Before we examine why this is and what could possibly be done about it, a more fundamental question is whether Platt is correct at all in identifying the existence of a problem. It seems clear from even a cursory examination of the history of science that Platt is at least partially correct: some sciences do progress significantly more than others. However, the pattern seems more complex than a simple line dividing “hard” from “soft” disciplines: it is true, say, that particle physics and molecular biology have made spectacular advances during the 20th century; but it is also true that physics itself went through long periods of stasis, for instance the long interval between Newton and Einstein, during which little or nothing was known about the intimate structure of matter. And such periods of slow progress may occur again in the future, even for “the queen” of sciences: for all the talk about a “unified theory of everything,” physicists have been trying to reconcile the known discrepancies between their two most successful theories, general relativity and quantum mechanics, for now close to a century; as yet, they have not gotten very far.

    Organismal biology (ecology and evolutionary biology) is often considered a quasi-soft science, and yet it has seen periods of great activity and progress -- most obviously with Darwin during the second half of the 19th century, and more recently during the 1930s and 40s. Moreover, there is currently quite a bit of excited activity in both empirical and theoretical evolutionary biology, which may be leading to another major leap forward in our understanding of how organisms evolve and adapt to their environments. Molecular biology, on the other hand, hailed by Platt as a very successful hard science on the model of chemistry and physics, may be running into the limits of what it can achieve without falling back on “softer” and more messy approaches to its subject matter: it is true that the discovery of the structure of DNA in 1952 is one of the all-time landmarks of science; but it is equally clear that the much-touted sequencing of the whole human genome has provided very few hard answers for biologists, instead leading to a large number of “bricks laying around the brickyard,” as Platt would have put it. We know a lot more about the human (and other) genomes, but much of what we know is a complex mess of details that is difficult to extricate and to make into a clear picture of how genomes work and evolve.

    All in all, it seems that one can indeed make an argument that different scientific disciplines proceed at dramatically different paces, but it is also true that the very same science may undergo fits and starts, sometimes enjoying periods of steady and fast progress, at other times being bogged down into a spell of going nowhere, either empirically (lack of new discoveries) or theoretically (lack of new insights).

    If we agree that the nature of science is along the lines I have just described, and that Platt therefore has a point, next we need to ask why it is so. [This post is a draft excerpt from a chapter of my forthcoming book, "Nonsense on Stilts: How to Tell the Difference Between Science and Bunk," to be published next year by the University of Chicago Press]


    The "hardness" or "softness" is seems a question of computational difficulty for competitive testing of theories; speed of "progress" based in part on the difficulty of search for alternate hypotheses better able to describe the data.

    Of course, I have a weird view of Science these days, since I mostly look at questions through the viewpoint of the Wallace-Dowe/Vitanyi-Li Minimum Length/Kolmogorov Complexity papers. It's a really nifty hammer, so everything looks like a nail.

    Dear Pigliucci:

    Please examine whether the theory of evolution is soft science or not.


    Jim Myres

    Medicine - something that we all depend upon at some point in life

    Physicians are treated like royalty (I work in a hospital so my point of view could be less than objective) and they participate in the softest type of science I can imagine.   Suppose engineers were constantly bombarded with misinformed request for solutions to their problems.  Misinformation that is generated by advertising to the public - if you don't understand what I am talking about you don't watch enough television. 

    When physicians  do have a solution to a problem it is the path-of-least-resistance - the Z-Pack is the best example.  How easy can this be, to wirte an Rx, all they have to do is write Z-Pack with directions "ud" and sign the Rx.  No thought goes into the quantity, the directions or duration of therapy.  Then there is the question - does the patient really need an antibiotic?  Did the physician determine if the patient had a viral or bacterial infection - antibiotics only work on bacterial infections.  Maybe the physician is treating the patient's need for "something."

    OK medicine may be an art, not a science but we don't let folks go to an art museum and draw on the portraits. 

    Sometimes delays in science are not what they seem.  The pupa may seem inert, but there is a tremendous amount of cellular reconstruction going on to turn a caterpillar into a butterfly.  Such a "pupation" is apparent in
    the long interval on the question of the nature of gravity between Newton and Einstein.
    You can't say that nothing was happening in the interval.  There was tremendous development of mathematics, and Special Relativity had to come first.  And what forced that hand was not the Michelson-Morley experiment, but Maxwell's equations of electromagnetism.  These didn't quite tie in with with Newton's ideas of force, and if one regards it as a competition between these two, it was Newton rather than Maxwell who had to give way.  As for incorporating gravity with General Relativity, it happened like this (in a comic-book sort of way).  Einstein was not the only one working on the problem; the Göttingen gang were closing in on it, with the formidable mathematical ability of Emmy Noether, whose
    first piece of work when she arrived in Göttingen in 1915 is a result in theoretical physics sometimes referred to as Noether's Theorem, which proves a relationship between symmetries in physics and conservation principles. This basic result in the general theory of relativity was praised by Einstein in a letter to Hilbert when he referred to Noether's "penetrating mathematical thinking."  It was her work in the theory of invariants which led to formulations for several concepts of Einstein's general theory of relativity. (MacTutor)
    One can imagine Einstein tearing at his hair, and turning to his friend Grossman and saying "Marcel, can you help me with this?", and Grossman replying "No, but I know a man who can", the man being Bernhard Riemann who had blown open geometry in the mid 1840, which led to the tensor calculus developed by three great mathematicians in the late 19th century.  

    Quantum theory did not come totally de novo, either.  I discovered how the Hamiltonian which is thrown at chemistry students has its roots in the 19th century by reading The Breakthrough by G. Venkataraman [1].  I highly recommend this series of books, especially A Hot Story (if thermodynamics bugs you) and The Many Faces of Matter.

    But one of the most spectacular cases of "pupation" is the replacement of the Ptolemaic system by the Copernican.  In the Middle East, Ibn al-Haytham (965-1040) saw many inconsistencies in the Ptolemaic system.  Here is how he replied to one of his critics:
    From the statements made by the noble Shaykh, it is clear that he believes in Ptolemy’s words in everything he says, without relying on a demonstration or calling on a proof, but by pure imitation (taqlîd); that is how experts in the prophetic tradition have faith in Prophets, may the blessing of God be upon them.  But it is not the way that mathematicians have faith in specialists in the demonstrative sciences.  And I have taken note that it gives him (i.e. noble Shaykh) pain that I have contradicted Ptolemy, and that he finds it distasteful; his statements suggest that error is foreign to Ptolemy.  Now there are many errors in Ptolemy, in many passages in his books.  Among others, what he says in the Almagest: if one examines it carefully one finds many contradictions.  He (i.e. Ptolemy) has indeed laid down principles for the models he considers, then he proposes models for the motions that are contrary to the principles he has laid down.  And this not only in one place but in many passages.  If he (i.e. noble Shaykh) wishes me to specify them and point them out, I shall do so.
    (translated by Roshdi Rashed)
    This work was given further mathematical development by Nasir al-Din al-Tusi (1201 - 1274), and in a recent television series Jim Al-Khalili shows a diagram in De Revolutionibus by Copernicus which corresponds to one by Al-Tusi, even using Roman letters corresponding to the Arabic ones of the earlier diagram.
    particle physics and molecular biology have made spectacular advances during the 20th century
    But particle physics is a bit stuck at the moment.  It seems that the Standard Model is now a bit "epicyclic" in character, requiring an input of 20 parameters in order to make it work, and looks as if it due for a "Copernican" overhaul.

    [1] This is part of an excellent series of books from India, the Vignettes in Physics by G.Venkataraman.  See them listed here.
    Robert H. Olley / Quondam Physics Department / University of Reading / England