We are delighted that our first post in the series is with Prof. Olimpia Lombardi, an esteemed philosopher of science with an interest in quantum mechanics and ontology in chemistry.
1. How did you get into philosophy and history of chemistry?
Actually, I started out working in philosophy of physics (a field in which I am still working). But about 20 years ago, one of my doctoral thesis students (Martín Labarca), who had a degree in chemistry, drew my attention to certain problems in the philosophy of chemistry related to the relationship between chemistry and physics. Thus, in 2005 we published what was my first paper in the philosophy of chemistry “The ontological autonomy of the chemical world” (Foundations of Chemistry, 2005, 7: 125-148), which had a very good impact in the field. In that paper, a neo-Kantian framework is applied to the problem of the relationship between chemistry and physics, a framework that I had already adopted for other problems in the philosophy of physics, such as the problems of determinism and irreversibility. Since then, I have continued to deepen this interdisciplinary relationship in order to elucidate the links between molecular chemistry and quantum mechanics.
It is worth clarifying that I have never ventured into the history of chemistry, since the history of science is a field in its own right, requiring a specific expertise that I lack.
2. What is your favourite question in the history and/or philosophy of chemistry?
As can be easily inferred from my previous answer, my favourite topic is the relationship between molecular chemistry and quantum mechanics. Besides my own background, I like this topic because it combines different aspects. On the one hand, the analysis of this relationship obviously requires an understanding of how molecular chemistry works. But on the other hand, it also requires a thorough knowledge of quantum mechanics and its interpretative problems. At the same time, it is a subject that goes to the very heart of certain traditional problems in the philosophy of science, such as the problem of reduction and emergence. It is precisely because of its many facets that this subject arouses my enthusiasm.
Of course, this does not mean that other topics unrelated to quantum mechanics are not central to the philosophy of chemistry; these topics are of even greater interest to many practicing chemists.
3. What is the value of philosophy and/or history of chemistry?
From a very general point of view, I am convinced of the importance of the philosophy of science for science. Philosophical reflection should not be a weekend hobby for scientists, but should be incorporated into their daily work, as it allows them to look at specifically scientific and technical problems from new perspectives; in turn, this undoubtedly opens the way to creativity and novelty, which are central to the development of science.
The above remarks are particularly relevant in the case of chemistry, because practicing chemists tend to stay further away from philosophy than scientists from other disciplines (physicists, biologists, etc.). The eminently practical nature of chemistry may have been one reason for this distancing. However, I believe that the main reason is the intuitive and even unconscious reductionism that permeates the world of chemistry up to now. Since the advent of quantum mechanics, the idea prevailed that chemistry is nothing beyond physics applied to molecules, so that any philosophical problem concerning chemistry is ultimately a philosophical problem of chemistry. Certainly, no philosopher of chemistry today adopts such a crude reductionism. But in the world of chemistry the idea is still strong and, I think, partially explains why, given the enormous number of practicing chemists today, relatively few of them approach the philosophy of chemistry.
4. What are you currently working on?
In the field of the philosophy of chemistry, I continue to work on the concept of molecular structure, which is central to chemistry. My position is that molecular structure cannot be explained in its entirety and without additional assumptions on the basis of quantum mechanics. Even if we adopt an answer to the problems of quantum measurement and of the classical limit of quantum mechanics, there remain obstacles to a comprehensive explanation, mainly related to the chemical phenomenon of isomerism (not only optical, but mainly structural).
Still in the same field, I continue to analyze the so-called Quantum Theory of Atoms in Molecules (QTAIM) of Richard Bader, working together with Chérif Matta, one of Bader’s main disciples. This analysis is central to the problem of the relationship between molecular chemistry and quantum mechanics because QTAIM was originally presented as an entirely reductionist solution to the problem. My analysis aims to unveil the limitations of such a position.
In recent years I have also started to study the application of Bohmian Mechanics to the field of quantum chemistry with Sebastian Fortin, ex-student and now collaborator. In several papers I have shown that there is a deep conceptual break between standard quantum mechanics and chemistry, even quantum chemistry. Bohmian Mechanics, on the other hand, proposes an ontology closer to the classical one, and therefore could provide a picture more akin to the implicit assumptions of quantum chemists.
In the more general field of the philosophy of science I continue to develop my neo-Kantian view, which leads to an ontological pluralism that rejects the ontological priority of certain domains over others. While this is a general thesis, it has an immediate application to the case of chemistry because it functions as an argument against the imperialism of physics.
5. How do you envision the future of the field? What are the areas/topics that you believe deserve more attention?
Regarding the future of the field, in a recent interview Eric Scerri asked me the same question and, as my opinion has not changed, I will answer basically the same.
I can’t guess how the development of the philosophy of chemistry will be in the next decades. Undoubtedly, it has become a well-established area in the field of philosophy of science, and this gives reasons to hope that it will continue to grow in the near future. However, the community of philosophers of chemistry is still very small, and efforts must be made to expand it in two directions. On the one hand, it is necessary to bring new, mainly young, people into the community in order to reach a “critical mass” that can be compared to that of philosophers of physics or of biology. On the other hand, we need to attract professional chemists into the field, precisely with the aim of bringing the practice of the discipline closer to the reflection on its philosophical foundations.
Regarding the second question, there are two topics that I would like to see further developed in the philosophy of chemistry. One is the extensive use of models in chemistry. I would like to see a closer look at the role of models in chemistry (is it the same as in physics or biology?), and at the peculiarity of chemical models, if they have any. Moreover, I believe that these analyses should be put into dialogue with the extensive literature on models in current philosophy of science. Two of my former students and now members of my research group, Juan Camilo Martínez González and Hernán Accorinti, are working in this direction.
The other, somewhat related, topic that I think needs to be addressed in more detail is what the philosophy of chemistry can offer to the general philosophy of science. In fact, the philosophy of science in the 20th century was almost entirely modelled on physics, so that the peculiarities of physics came to be conceived as characteristics of science itself. Chemistry and its philosophy clearly show that, on the contrary, there are many different ways of doing science. For example, in chemistry, models play a more prominent role than laws; laboratory practice is an activity that can hardly be separated from theoretical reflection, among other peculiarities. These ways of doing science can help to open the minds of scientists from other disciplines, particularly physicists.
6. A recently published paper or book that you would recommend reading?
This question gives me the opportunity to “publicize” the recent book I edited with two of my collaborators: Lombardi, O., Martínez González, J. C., and Fortin, S. (eds.) (2022). Philosophical Perspectives in Quantum Chemistry. Cham, Switzerland: Springer Nature, Synthese Library. The book is organized in three parts. Part I groups four chapters mainly devoted to inquiring into the very nature of quantum chemistry from historical and pragmatic perspectives. Part II is composed of two chapters that analyze, from different standpoints, the central role played by scientific models in quantum chemistry. Finally, Part III, with its four chapters, tackles directly the issue of the inter-theory and inter-disciplinary links involved in quantum chemistry.
I think that the philosophical reflection on quantum chemistry is relevant for two reasons. On the one hand, quantum chemistry’s intermediate position between chemistry and physics makes it a privileged arena for discussing inter-theoretic and inter-disciplinary relationships. On the other hand, quantum chemistry demands rethinking the picture of science of the traditional philosophy of science; in fact, from the outset, it outlines its identity, not around a theoretical body, but as an activity that integrates theoretical elements and methodological strategies coming from chemistry, physics, mathematics, and informatics.