Besides reading Chemistry: The Impure Science, as mentioned in my previous post, I’m also working my way through another philosophical treatise, Aristotle’s Revenge by Edward Feser. Both books are making me ponder my chemistry teaching, which is something I enjoy thinking about.
In reading about the nineteenth century debates between the atomists and the energeticists (each label likely used pejoratively by the opposing camp), I was struck by similarities to how we divide our General Chemistry curriculum into its two semesters. With the rise in popularity of “Atoms First” arrangements in textbooks, we focus on “microscopic” (more accurately nanoscopic) molecular structure in the first semester, and turn our attention to “macroscopic” energy considerations of thermodynamics and equilibria in the second semester.
But we chemists are practical folks and to learn chemistry we need to talk about the macro and microworlds together! Hence, while we focus on the micro in the first semester, we introduce the concept of the mole; we balance chemical equations and do stoichiometric calculations; energy makes its appearance in the interaction of light and matter with photons and electronic structure; we discuss trends in the periodic table (introducing ionization energies); we discuss phases of matter and draw phase diagrams; and when we focus on gases we introduce the macroscopic properties of pressure and temperature. In the second semester focusing on the macro, thermochemistry and enthalpy changes are connected to making and breaking chemical bonds; kinetics envisions molecular-level collisions; we get into molecular nitty-gritty discussing entropy; and molecular pictures abound throughout equilibria and electrochemistry.
I’d like to think that chemistry has survived the overly-reductionist program at the forefront of mathematical physics. Yes, on the one hand we try to explain macro chemical phenomena in terms of nano molecular interactions. But on the other hand, we’re eager to develop tricks to make new macroscopic materials based on some guesswork and theory of the microscopic which we don’t quite understand as messiness increases very quickly. Yes, there’s rational design, but we still employ the alchemist’s approach of trial and error – there’s no substitute for doing the experiments with actual stuff, not just on the computer. We do analysis, yet synthesis is our goal; but synthesis is not the exact opposite of analysis, we chemists aim to create new things! We’re often classified as “pure” scientists, but we’re also artists and engineers and share much in common operation.
Much of metaphysical philosophy of nature focuses on ‘ultimate reality’, whatever that means. It’s a physicist-reductionist view (although not all physicists are reductionists). Is water H2O? Is temperature molecular motion? Can we explain everything as the motion of atoms through the void? Feser, as a neo-Aristotelian, would argue no. Rather he revives the Aristotelian ideas of potentiality and actuality to reframe such questions and break the seeming dichotomy behind the static monism of Parmenides and its dynamic counterpart advanced by Heraclitus.
Two ideas from the Aristotelian school dovetail with the categories of atomism and energetism. These are substantial form and prime matter. In anything that’s ‘real’ both aspects must be present. I don’t exactly understand how they work together, but maybe that’s the point – these are abstractions and a simplistic attempt to strictly limit oneself to discovering just the efficient cause (to use another Aristotelian idea) is bound to fail. Prime matter, being protean in nature, is associated with aspects of energetism. Atomism on the other hand seems largely associated with substantial form, but more in the idea of what an Element represents rather than our physicist picture of an Atom.
This last conundrum is one thing that’s always bothered me whenever I teach first-semester general chemistry. The definition of Element has always been nebulous (much like the definition of energy). I use it operationally, rather than try to discuss its essence, in class. After a while students get the operational idea and think of it as a label, although I wonder if deep down they’re uncomfortable with what it really means. Water is elemental in a sense that we designate it a “pure substance” as opposed to a “mixture”. But it’s non-elemental when we designate it as a “compound” composed of one or more “elements” – and now I’m using the word element in more than one sense making things even more confusing. In the second semester, we define reference states as “pure elements in their standard states”. At this point, my students take this in stride because they treat element as a label, H for hydrogen, O for oxygen, and so on.
The alchemists used the term “mixt” which sometimes corresponds to our definition of “compound” and sometimes to our definition of “homogeneous mixture”. We think of the two differently, and further distinguish it from “heterogeneous mixture” – and then try to parse a distinction between “physical” and “chemical” separations using these crude categories. These definitions are in every standard college chemical textbook. I don’t spend much time on them. I understand why they’re useful as a scaffold to help students categorize the many things we’re going to be throwing at them throughout their year in general chemistry. But deep down I feel ambivalent about this terminology. And because chemical bonding is one of my areas of chemical expertise, I see problems down the road with these categorizations. Are we indeed carving nature at its joints? As the practical chemist, though, I press on – knowing that we see nature “through a glass darkly” and perhaps that’s one of the exciting things about being a scientist, a philosopher of nature.
P.S. Reading philosophy of chemistry has motivated me to adapt my Potions Project to my General Chemistry classes next semester. Time will tell if the potential will actualize!
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