Can chemistry really be reduced to physics, or do concepts like elements and the periodic table show that it has its own irreducible structure?
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1. Guest
Eric Scerri is a lecturer at UCLA, and focuses on chemistry, the philosophy of chemistry, and science more generally.
2. Interview Summary
Eric Scerri argues that philosophy of chemistry arrived relatively late partly because chemistry sits so close to physics in the usual “hierarchy of the sciences,” which encourages the popular thought that chemistry is “nothing but” physics—and so not in need of its own philosophical scrutiny. He suggests that the right question isn’t whether chemistry is or isn’t reduced to physics (as if it were all-or-nothing), but how far reduction goes and in what sense, since both scientific practice and philosophical models of reduction have shifted over time. On his picture, the most sensible stance is to talk about “degrees” of reduction that can increase as molecular quantum chemistry advances, rather than expecting a clean yes/no verdict.
A major theme is the concept of a chemical element: Scerri emphasizes that “element” is used in (at least) two senses—an element as a simple substance (often associated with Antoine Lavoisier) and an element as a more abstract bearer of properties (revived in Dmitri Mendeleev’s thinking about the periodic system). He illustrates the abstract sense by noting that pointing to “carbon” on the periodic table is not pointing to diamond or graphite (or any particular isotope), but to something that underlies them all—something that can be characterized in modern chemistry chiefly by atomic number. He then uses the sodium/chlorine → sodium chloride case to argue that the familiar simple substances can “disappear” in compounds while the elements persist in the abstract sense, which helps explain chemical novelty. Scerri adds that this dual usage is often left implicit (even by IUPAC), and that chemical education tends to foreground orbitals and electron configurations so early that students may lose contact with the ordinary chemical character of substances.
On the periodic table, Scerri discusses the “left-step” proposal that moves helium into group 2 on electronic-configuration grounds, and he defends the idea that (beyond mere representational convenience) it can still make sense to ask which table is most fundamental. This connects to his broader view of reduction: he distinguishes epistemological reduction (always partial and a matter of degree) from ontological reduction, where he favors a “unity of science” picture on which chemistry is not a free-floating realm apart from physics—so reduction is more a direction than an achievable final goal. Methodologically, he leans instrumentalist about theoretical posits like orbitals—useful mathematical constructs rather than the kind of thing one literally “images”—and he’s skeptical of philosophical debates that ignore how working scientists treat things like laws and bonding. Finally, he stresses a broadly evolutionary picture of scientific change, where even apparent revolutions have extended build-ups, detours, and pragmatic rule-breaking that matter more than tidy, armchair reconstructions. Transcript:
3. Interview Chapters
00:00 - Introduction
00:52 - Neglected field?
04:36 - Elements
08:31 - Too abstract?
09:46 - Advantages of abstract view
12:04 - Atomic number enough?
14:38 - Chemical education
22:10 - Periodic table
27:01 - Best table?
30:20 - Helium
33:14 - Historical development
38:38 - Orbitals
40:08 - Chemical bonding
45:55 - Theoretical reduction
49:12 - Limitations of reduction
51:48 - Orbital filling
53:50 - Ontological reduction
54:52 - Ontological levels
58:56 - Ideal theory
1:00:24 - Prospects of reduction
1:01:44 - Other issues in philosophy of chemistry
1:04:52 - Laws
1:08:31 - Metaphysics
1:09:19 - History of chemistry
1:12:12 - Scientific revolution
1:15:30 - Value of philosophy
1:17:08 - Conclusion
