Why philosophy of chemistry?

Over at Philosopher's Playground, Steve Gimbel asks why the philosophy of chemistry is such a recent discipline given how long there has been serious activity in the philosophy of biology and the philosophy of physics.

He floats a few possible answers -- as it happens, the same options those of us who actually do philosophy of chemistry encounter fairly regularly. After responding briefly to these possible reasons for thinking that there shouldn't be a distinct philosophy of chemistry, I'll offer a brief sketch of what a philosophy of chemistry might be about.


(1) There are no big questions in chemistry that are not already somewhere else.

I suppose it all depends on what you count as a "big question" for a subfield of philosophy. Steve mentions the origin of the universe as a big question for philosophy of physics (and we can add to that questions about the nature of time, space, and matter) and the origin of life as a big question in the purview of philosophy of biology (to which we might also add questions about our fundamental human nature).

What big questions are left for chemistry?

Surely there are interesting questions to be asked about the nature of change. Chemistry is a science that concerns itself with transformations of matter. To the extent that different substances are part of our reality, there are interesting and important questions about the nature of substances -- what it is that defines a substance and its characteristics, what features persist in transformations and which do not. (Some of these play out in particular questions like "Is there any salt in the sea?" Joe Earley says there isn't, while Paul Needham argues that there is.)

Not every philosopher will view these as earth-shaking questions, but then again, there are plenty of philosophical questions to which serious scholars have devoted their whole careers but whose pull is ... let's say "elusive" to others of us. (For example, the problem of universals, to me, has never seemed a "problem" worth losing sleep over.)

(2) Chemistry does not actually exist -- or at least it won't forever.

That would explain why physics departments are so huge and well-funded, while chemistry departments have shrunk down to nearly nothing.

Oh, wait! That hasn't happened!

Maybe chemistry won't survive as a distinct discipline to the moment at which the human race ceases to be. But I think it's an empirical question. And given that string theory has not so far revolutionized organic synthetic design, I wouldn't bet on chemistry's obsolescence in the foreseeable future.

(3) It's the chemists -- they just aren't a philosophical bunch.

The chemists who attend the meetings of The International Society for the Philosophy of Chemistry are an interesting bunch, but I don't think they're complete outliers. Many chemists of my acquaintance are at least somewhat interested in the philosophy of science -- and this was the case even before I crossed the line to become a philosopher.

Anyway, for any X, it strikes me that there could well be a philosophy of X even if it were only the philosophers and not the practitioners of X themselves who were interested in any of the philosophical implications of topics within X. Philosophers are competent to decide what issues of theory and practice are of interest to them without seeking affirmation from the folks who happen to use those theories or engage in those practices. I'm not saying engagement between practitioners of X and philosophers of X is not often productive, but it's not a requirement for there to be a philosophically interesting "there" there.

(4) It's the philosophers -- they just don't know any chemistry.

For awhile, this might have been closer to the truth. The Vienna Circle was all about the physics, after all. Not that this didn't stop philosophers from turning to chemistry as a source of example to help support the philosophical claims they were trying to make. What kind of support those examples actually provided, it turns out, depends on how fully the audience to be persuaded grasps the piece of chemistry being waved around. (This is why nearly every philosopher who has done any work in the philosophy of chemistry, and many a chemically literate who has not, has at some point written a paper on Hilary Putnam's Twin Earth water example. A large number of these papers point out that water is not H2O -- at least not in the unproblematic way Putnam thought it was.)
However, there are significant numbers of philosophers out there nowadays who have significant training in chemistry (from an undergrad minor to a B.S. to an M.S. to the odd Ph.D.). Not all of them are doing work in philosophy of chemistry, but a bunch of them are. And, perhaps more importantly, these folks may be reaching a critical mass to overcome the "Physics rules, chemistry drools!" biases of the old guard in the philosophy of science. (That old guard, as well, is starting to die off. It's the circle of life.)

There are distinctive and important philosophical questions about how chemistry engages with the world. Here are just a handful of the ones I find interesting (as I described them in an abstract I wrote a couple years ago):

Chemical models and chemical phenomena. In trying to understand the range of chemical entities and phenomena (atoms, bonds, molecules) and phenomena (such as chemical reactions), chemists use an astounding array of models. These range from the very abstract and mathematical to the "tinker-toy" models of molecular structure familiar to chemistry students. The prevalence of models here illuminates the different roles models play in the practice of science, as tools for predicting and explaining, but also for creating novel molecules and for reasoning about molecules whose existence is deemed impossible. It also presses the question of what sort of correspondence is required between a model and the entity or phenomenon being represented. (Chemical bonds are understood to be vastly different from sticks, yet the ball-and-stick models of molecules still convey useful information. How?)

Measurements, explanations, realism, and instrumentalism. Chemistry is a science whose experimental prowess has at times outrun its theoretical resources. Yet it has made use of the proximity of physics to augment those resources. As a result, chemists sometimes have multiple models for the same entities or phenomenon - models that seem to make contradictory claims (e.g., about what a bond is "really" like). Do chemists require only that their models fit with the observables while making no commitments about whether these models get at the "true structure" of chemical stuff? Do chemists try to choose from among multiple models that fit equally well with the observables to get closer to such truths? The ways chemists navigate comparisons of models and measurement illustrates methodological advantages and disadvantages of realism and instrumentalism.

Policing the border: reduction, autonomy, or some intermediate position? One solution to the question of what makes for a good model in chemistry might be to impose constraints from the best physical theory. However, this is not what chemists do - even quantum chemists' descriptions of atoms and bonding violate strict quantum mechanical theory - nor is it clear that chemistry would be better off in accepting this constraint (since, for example the features of quantum chemical models that are explanatory are the classical features, not the quantum ones). Is chemistry accountable to the claims of physical theory as well as to empirical features of chemical phenomena? Where these come into conflict, how does chemical theory and practice respond? What lessons might the relation between chemistry and physics have for questions of reduction and the unity of science?

I suppose I haven't provided a positive answer to Steve's question about why there wasn't a critical mass of philosophers of chemistry before the 1990s. However, I hope I've provided at least a reason to think that there are important philosophical questions worth pursuing in it, even if there's still some mystery about why they weren't noticed for so long.

Comments are off for this post

  • Brandon says:

    Philosophy of chemistry really isn't a recent discipline; it goes back to Lavoisier himself, who, in fact developed chemistry in part out of his philosophical reflections, inspired by Condillac, on the function of language in knowledge (and the inadequacy of chemical classifications up to his time to provide a language capable of fulfilling that function adequately). It's discussed to some extent by Sir John Herschel (who was a chemist himself), and at even greater length by William Whewell (and, indeed, allowing for some quirks due to the amount of chemistry that has been done since the nineteenth century, a number of the ideas circulating in modern philosophy of chemistry, e.g., issues of Hyle, are already found in Whewell in some form). Pierre Duhem, who was interested in chemistry from a thermodynamics perspective, wrote a whole book on it. The real question is not why philosophy of chemistry is a recent discipline, since it is as old as chemistry itself, but why it completely fell off the radar for almost a century. (It's possible that the answer to the riddle may lie with the answer to similar riddles -- e.g., the almost complete dissipation of interest in classification as a philosophical issue.)
    I've always liked Weisberg's paper; ever since I first discovered it I try to get as many people as I can to read it.

  • Doc says:

    In college I once had a friend tell me there are only two kinds of people who go into chemistry. People who want to get high and people who want to blow stuff up. It is interesting looking at the historical breakthroughs how often this seemed to be the case. Could this the reason?

  • PhysioProf says:

    Steve mentions the origin of the universe as a big question for philosophy of physics (and we can add to that questions about the nature of time, space, and matter) and the origin of life as a big question in the purview of philosophy of biology (to which we might also add questions about our fundamental human nature).

    Maybe I'm confused about what philosophy is, but it seem to me that these are not philosophical questions, but rather substantive scientific questions central to the disciplines of physics and biology. The fact that these questions are difficult to address methodologically, and thus current provisional answers are highly speculative, doesn't make them philosophical, does it?
    Again, maybe I have no fucking clue what I'm talking about, but I thought philosophy of science concerned itself with the conceptual structure of scientific discourse, experimental proof, etc.

  • Noumena says:

    And just to complement PhysioProf's reaction (`isn't this just chemistry, not philosophy of chemistry?'), I'll react by asking whether this isn't just philosophy (of science), not philosophy of chemistry?
    I sat in on a philosophy of biology reading group this semester, and the issues discussed were pretty much exactly the three on your list: how models work, epistemologically and practically; realism; and reduction. So, at least prima facie, philosophy of chemistry deals with the same sorts of problems as philosophy of biology. Presumably the philosophical methods are the same, too, viz., look carefully at the science, sit back and do some conceptual analysis, read a book written before 1905 (that one's optional), write a paper on all of it, repeat.

  • leigh says:

    The (or a) problem with Weisberg's argument is his implicit requirement that a substance be a natural kind, or at least uniform at an arbitrary particular resolution. One broadens the resolution and his problem evaporates (pun intended); water is indeed H2O. One sharpens the resolution and even isotopically identical atoms and molecules (to ignore intermolecular interactions) become variable, as with movement of an electron to a higher orbital. One doesn't even need polythetic classes to deal with the situation, although fuzzy sets could help from one perspective.

  • SteveG says:

    Let me be clear that I am in no way questioning the legitimacy of phil chem (a field I admire, teach, and follow), but find it fascinating that it has taken this long for the intellectual infrastructure of the study to be laid down.
    Brandon is absolutely correct that the history of the philosophy of chemistry in some sense goes well back into the 17th century when Boyle was trying to separate the experimental/theoretical movement that would become modern chemistry from alchemy. (Before that, one could look to Paracelsus for a philosophical justification for extending the alchemical project). That philosophical edge continued through the 18th and 19th century with the realist/instrumentalist debate swirling around the notion of atoms, with most serious chemists denying atomism because it threatened to throw chemistry back into the business of speaking about the mysterious unobservable and this smacked of alchemy. Even as late as the 20th century, huge names like Ostwald and Mach still denied the existence of atoms.
    I believe that is part of the answer. Chemistry has been so committed to distancing itself form its history as alchemy that any sort of mushy philosophical ontological (I won't even use the word metaphysical) discussions were seen as undermining the legitimacy of the project. As such, chemistry as a community has adopted the sort of anti-philosophical stance that we see in the writings of Feynman, who despised philosophy despite being extremely philosophical.
    Philosophy of physics enjoyed the support of prominent physicists (Reichenbach -- one of the founders of phil of phys -- was pushed onto the Berlin faculty by Einstein and when the phil faculty refused to give him a chair, he had a new one created in the physics department dedicated to the foundations of physics.) Similarly, philosophers of bio have worked alongside biologists in the trenches of the creation/ID battles not only recently, but going back decades. Linguistics, cog sci, and other fields have been deeply tied into the philosophical community and that helped legitimize them. But it has not been the case in chemistry and the question is why.
    The big questions are undoubtedly there. Reductionism in the naive version will either fail or, even if possible in principle, not matter. But there is something to 3 and 4 that speaks to the sociological conditions within the culture of chemistry that seem to be worth investigating.

  • bob koepp says:

    Why philosophy of chemistry? Because there are lots of interesting phenomena that, given our current way of talking about things, are categorized as chemical phenomena. Whether there's any "natural" division between chemical phenomena and those of physics, biology, or cooking [;-)] is one of the questions philosophy of chemistry addresses.
    Why philosophy of chemistry and not _just_ chemistry? Becuase too few people appreciate that understanding most interesting phenomena involves sorting through both empirical and conceptual problems.
    My own background is in the philosophy of cognitive science and philosophy of biology. In both areas, I became convinced that the difference between philosphy of cogsci/biology and theoretical cogsci/biology was a matter of what department one called 'home'.

  • Grebmar says:

    I would add that history of chemistry has had the same relative lack of interest among historians of science. Historians of biology, physics and astronomy are a dime a dozen, but you can count prominent historians of chemistry on two hands, and maybe a foot (there are probably even fewer historians of geology, but that's another matter).
    My answer to this problem has generally been the pragmatic character of chemists--they are interested in solving some sort of materials problem (new drugs, new paint, cements and glues, etc), that doesn't require much thought about philosophical implications of chemical entities. As a science, chemistry has been so successful that it is, in a sense "completed" and therefore no big scientific/philosophical problems remain.
    Yet, chemistry does have "big questions"--one of the most fundamental, and the oldest is the nature of "elementary" bodies themselves. What is a simple substance, what is an element, and is there a difference between these two concepts?, and, more importantly, _how do you know_ when you have found a simple substance? Forming a satisfactory answer to this question took hundreds of years. The periodic table itself is loaded with philosophical questions about elements, representation, natural kinds, etc.
    Finally, while there is an active group in philosophy of chemistry, I have had the impression that they have not necessarily been taken seriously by the rest of philosophers of science (by which I really mean philosophers of physics). But I may be mistaken about this.

  • Propter Doc says:

    Hmmm, I'd suggest 'The Chemical/Molecular Basis of Life' as a pretty big fundamental question for chemists to tackle. No, it is not the exclusive domain of molecular bio/biochem but rather wading through the primordial ooze to find out what chemistry was taking place.
    Chemistry is particularly cursed as a science because it is located between the extremes of physics and biology, donating and accepting from both sides. The philosophy of physics or biology would then overlap with the philosophy of chemistry.

  • SteveWH says:

    PhysioProf - Don't forget your history! When the natural sciences as we know them were just figuring out what they are, they were called "natural philosophy", and were developed and practiced by the philosophers of their time. Historically, our sciences are an outgrowth from philosophy, and still carry with them close ties to philosophy. Even though the sciences are more familiar to people today and many people hear philosophical questions in scientific contexts and say, "That's just science," the truth is, priority goes to philosophy.
    That all said, especially when dealing with more abstract and theoretical questions, there is no distinct line between "science" and "philosophy". Distinctions between physics and philosophy departments may make sense form the point of view of college administration, but not from the point of view of the subject matters. They bleed into each other.
    Noumena - I think the difference is level of specificity. Philosophers of science will address these questions in a general sort of way, drawing general conclusions that are fairly universal for all sciences, while philosophers of biology will look at more specific instances. Again, these are not clear distinctions - you really can't and shouldn't try to do one without being informed by the discussions in the other. But, "philosophy of science" and "philosophy of biology" are useful labels.
    Second, I don't have the time or space to say much on your description of philosophical methods, but I will say, it's overly simplistic.
    Third, there are also many other questions which can and should be addressed by the philosophy of a particular science. One important that I'm surprised hasn't been raised here deal with the social/political/ethical implications and effects of the disciplines. While most people, in my experience, think of the metaphysical, logical, and epistemological questions of the philosophy of science, relatively few think of the ethical questions. Chemistry has had a profound effect on our world and our understanding of it, and the social/ethical side of those changes are rich grounds for philosophical work.

  • jesus zamora says:

    It's really a pitty that philosophers of science haven't paid much attention to chemistry (I don't agree with the one who said that historians of science hadn't; at least, they have studied the history of chemistry much more than philosophers have).
    Physics and biology have attracted more interest surely due to their 'intrinsic' philosophical interest (for metaphysics, ethics, and so on), but chemistry is probably the best exemplication of what science is, of the kind of intellectual, practical and institutional activity science consists in.
    So, every effort in making chemistry more attractive from a philosophical point of view is welcome.

  • David Marjanović says:

    almost complete dissipation of interest in classification as a philosophical issue

    What do you mean? The fact that it has moved from classification to nomenclature in biology?

    it seem to me that these are not philosophical questions, but rather substantive scientific questions central to the disciplines of physics and biology. The fact that these questions are difficult to address methodologically, and thus current provisional answers are highly speculative, doesn't make them philosophical, does it?

    Exactly.

    Reductionism in the naive version will either fail or, even if possible in principle, not matter.

    What do you mean by "naive version"?
    After all, the whole is more than the sum of its parts -- it's the sum of its parts plus the sum of the interactions between the parts plus the sum of the interactions between these interactions and so on. Therefore, we start by trying to identify the parts, then their interactions, then the interactions between these interactions, and so on... shouldn't we?

    Hmmm, I'd suggest 'The Chemical/Molecular Basis of Life' as a pretty big fundamental question for chemists to tackle.

    Yes, but, again, this is a scientific question.

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