A Unified Theory of the Second Scientific Revolution, Part 1: the Problem
Gaston Bachelard (1882-1962) forming the scientific mind.
There are two kinds of conference paper: the ones we give, and the ones we would have given if only we had been able to do enough research to back up our seductive hunches and our bold conjectures. At the 3 Societies conference in Edmonton in July, I gave a modest talk about an experimenter in 1730s France who had a notion of ‘exactitude’ that applied equally well to qualitative and quantitative research. The talk I would have given is much more sweeping and provocative. Frankly I would have preferred to listen to the ambitious talk, and not the modest and sensible one, but academic caution got the better of me. Here then is the sweeping and provocative talk, in summary form, safely packaged as a speculative blog post (or two).
What was the second scientific revolution, or SSR for short? Many historians of science believe that something dramatic happened to the natural sciences in the decades around 1800. According to no less an authority than the Oxford Companion to Modern Science, this period witnessed ‘the transition to modern science.’ But there is no agreement on how to characterise this all-important event, as we can see be reviewing some of the literature on the topic (see the end of this post for citations of the books and articles I have in mind).
Hélène Metzger, writing about the history of crystallography, thought that this was the period when naturalists abandoned the search for the causes of crystal form and focused on describing that form, preferably in mathematical terms.
Gaston Bachelard extended this account to physics and chemistry. He made much of Coulomb’s discovery of the inverse-square law of electrical force. For Bachelard, this discovery marked a shift from a qualitative, allegorical, diffuse physics to a quantitative, abstract, precise physics.
Michel Foucault’s account was almost the opposite of Metzger’s and Bachelard’s. According to Foucault, it was the first two-thirds of the eighteenth century that was obsessed with abstraction and classification (witness Linnaeus’ natural history) and it was the period around 1800 that saw the rise of a historical and causal natural history, one that studied the inner constitution of bodies and not just their surface appearances (witness the comparative anatomy of Cuvier).
Thomas Kuhn had little to say about classification or inner constitutions or the historical sciences, but he had much to say about physics and mathematics. He characterised the SSR (he was one of the first to use the phrase) as the period when terrestrial physics became quantitative. Astronomy had been quantitative for millennia, and some branches of terrestrial physics (such as optics) had a long history of geometric treatment. But what of chemical processes, electricity, heat, and magnetism? As Kuhn pointed out, it was only in the last third of the eighteenth century that these phenomena were measured with precise instruments and described with mathematical theories.
John Heilbron, in one guise, has put his finger on what was needed to apply Newton’s approach to celestial mechanics to terrestrial phenomena, and especially to electricity and magnetism. The key to establishing Coulomb’s law of electrical force, for example, was to see that the forces between macroscopic charges are complicated aggregates of the forces between the microscopic charges. Coulomb found a simple force law because he measured the forces between insulated spheres whose separation was large compared to their diameters.
John Heilbron, in another guise, and in concert with Tore Frängsmyr and Robin E. Rider, has argued for the existence and importance of a ‘quantifying spirit’ in the last third of the eighteenth century. Heilbron and his co-authors define this spirit broadly to include not just precise instruments but also systematic methods of classifying plants, animals and minerals.
Finally, John Pickstone argued that the key to events around 1800 was what he called ‘the analytical way of knowing.’ His best example was chemistry. The chemical revolution initiated by Lavoisier and co. was defined above all by the idea that substances are what they are made up of, where ‘what they are made up of’ does not mean ‘what philosophers consider fundamental’ but ‘what you get when you take them apart.’ Pickstone generalised this point by saying that the SSR saw the convergence of natural history, in the sense of surface descriptions of phenomena, and natural philosophy, in the sense of deep explanations of phenomena. Whereas these two activities had been practised separately before, as two ‘layers’ of knowledge, now they were practised as one.
The problem with these seven theories of the SSR is that they are hard to reconcile with each-other. Metzger and Bachelard detect a shift away from causes and towards surface description, whereas Foucault detects a shift in the opposite direction. Pickstone gestures towards Foucault with his talk of ‘deep causes’, but unlike Foucault he thinks that the novelty was not the interest in deep causes per se but the convergence of that interest with the description and classification of natural bodies.
It gets worse: three of the above authors (Kuhn, Metzger, Bachelard) think that mathematics was an important part of the story, whereas two others (Pickstone and Foucault) give it a secondary role.
Pickstone’s thesis is probably the pick of the bunch, but it is far from perfect. He claims that natural history and natural philosophy were separate in the eighteenth century, whereas other historians maintain that the grounding of natural philosophy on natural history was the main achievement of seventeenth-century science. And if analytical thinking means understanding a whole in terms of its parts, as Pickstone sometimes suggests, surely this applies as much to the metaphysics of Descartes as it does to the chemistry of Lavoisier?
My sweeping and provocative idea is this: we can resolve these conflicts, and get a more unified account of the SSR, by weaving together the best ideas of the six thinkers I have just reviewed. The unification proceeds in three steps, to be outlined in the next post.
Metzger, Hélène. La genèse de la science des cristaux. Paris: Albert Blanchard, 1969.
Bachelard, Gaston. La Formation de l’esprit scientifique: contribution à une psychanalyse de la connaissance. Vrin, 1934.
Foucault, Michel. Les mots et les choses: une archéologie des sciences humaines. Paris: Gallimard, 1966.
Kuhn, Thomas. ‘Mathematical Versus Experimental Traditions in the Development of Physical Science’. Journal of Interdisciplinary History 7, no. 1 (1976): 1–31.
Heilbron, John. Electricity in the 17th and 18th Centuries: a Study of Early Modern Physics. Berkeley: University of California Press, 1979.
Frängsmyr, Tore, J. L Heilbron, and Robin E Rider, eds. The Quantifying Spirit in the 18th Century. Berkeley: University of California Press, 1990.
Pickstone, John V. ‘Ways of Knowing: Towards a Historical Sociology of Science, Technology and Medicine’. The British Journal for the History of Science 26, no. 4 (1993): 433–58.
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