The Strong Emergence of Molecular Structure
Accepted/In Press in The European Journal for Philosophy of Science
Abstract. One of the most plausible and widely discussed examples of strong emergence is molecular structure. The only detailed account of it, which has been very influential, is due to Robin Hendry and is formulated in terms of downward causation. This paper explains Hendry’s account of the strong emergence of molecular structure and argues that it is coherent only if one assumes a diachronic reflexive notion of downward causation. However, in the context of this notion of downward causation, the strong emergence of molecular structure faces three challenges that have not been met and which have so far remained unnoticed. First, the putative empirical evidence presented for the strong emergence of molecular structure equally undermines supervenience, which is one of the main tenets of strong emergence. Secondly, it is ambiguous how the assumption of determinate nuclear positions is invoked for the support of strong emergence, as the role of this assumption in Hendry’s argument can be interpreted in more than one way. Lastly, there are understandings of causation which render the postulation of a downward causal relation between a molecule’s structure and its quantum mechanical entities, untenable.
Referring to chemical elements and compounds: Colourless airs in late eighteenth century chemical practice
In book: What Is A Chemical Element? A Collection of Essays by Chemists, Philosophers, Historians, and Educators
co-writtern with Geoffrey Blumenthal & James Ladyman
ed. by E. Scerri and E. Ghibaudi (Oxford University Press)
The Role of Idealisations in Describing an isolated molecule
Published in Foundations of Chemistry
Abstract. The investigation of the relation between chemistry and quantum mechanics includes examining how the two theories each describe an isolated molecule. This paper focuses on one particular characteristic of chemistry’s and quantum mechanics’ descriptions of an isolated molecule; namely on the assumptions made by each description that an isolated molecule is stable and has structure. The paper argues that these assumptions are an idealisation. First, this is because stability and structure are partially determined by factors that concern the context in which a molecule is considered (i.e. thermodynamic conditions, time-range of experiment, environment, etc.). Secondly, the stability and structure of a molecule can only be empirically identified with reference to those factors. This paper examines these assumptions in the context of the philosophical literature on idealisations. This examination is a novel contribution that raises interesting questions about the relation between the two theories, the nature of stability and structure, and the function of these assumptions in the two theories.
Published in the Internet Encyclopedia of Philosophy
This encyclopedia article presents how chemistry’s relation to physics has been understood in philosophy. Chemistry’s relation to physics, and in particular to quantum mechanics, is one of the most discussed issues in the philosophy of chemistry literature. This article situates this discussion around the dilemma between reduction and emergence. While there is a broad consensus that chemistry is not epistemically reducible to quantum mechanics, some have argued that there are epistemic and metaphysical connections between the two sciences which can be spelled out by an alternative form of reduction or unity. On the other side of the spectrum, there are philosophers who argue for the autonomy of chemistry from quantum mechanics in terms of different accounts of pluralism and emergence. The aim of this article is to present the central views on this debate.
Published in Foundations of Chemistry
Abstract. Harold Kincaid in Individualism and the Unity of Science postulates a model of unity-without-reduction in order to accurately describe the relation between individualism and macroeconomics. I present this model and apply it to the description of the relation between chemistry and quantum mechanics. I argue that, when it comes to the description of molecular structure, chemistry and quantum mechanics are unified in Kincaid’s sense. Specifically, the two disciplines contribute to the formation of a unified body of knowledge with respect to molecular structure.
Essays in the Philosophy of Chemistry
Published in the International Studies in the Philosophy of Science
Review of the book Essays in the Philosophy of Chemistry, edited by Eric Scerri and Grant Fisher, New York, Oxford University Press, 2016, x + 410 pp., ISBN 9780190494599, US$59.95, £38.99 (hardback)
A Philosophical Analysis of the Relation between Chemistry and Quantum Mechanics: The case of a single inert molecule
Abstract. This thesis investigates the epistemological and metaphysical relations between chemistry and quantum mechanics. These relations are examined with respect to how chemistry and quantum mechanics each describe a single inert molecule. A review of how these relations are understood in the literature shows that there is a proliferation of positions which focus on how chemistry is separate from quantum mechanics. This proliferation is accompanied by a tendency within the philosophy of chemistry community to connect the legitimacy of the field with the autonomy of chemistry. First, it is argued that this connection should not be made. Secondly, it is argued that chemistry and quantum mechanics are unified in accordance with Harold Kincaid’s model of non-reductive unity because the two theories exhibit particular epistemic and metaphysical interconnections. Thirdly, a metaphysical account is examined which is incompatible with Kincaid’s model of unity; namely strong emergence as understood by Robin Hendry. According to Hendry, the structure of a single inert molecule strongly emerges from its quantum mechanical entities in the sense that there is downward causation. However, Hendry’s defense of this account faces certain problems. Moreover, the putative empirical evidence for his understanding of strong emergence can be explained without invoking strong emergence. This is shown by considering how quantum mechanics assumes an idealized understanding of a molecule’s stability and structure. In the light of the philosophical literature on idealizations, this idealization can be interpreted in two different ways, both of which explain why quantum mechanics describes the structure of a single molecule the way it does, without assuming strong emergence in Hendry’s sense. Each interpretation has philosophical implications regarding the nature of chemical properties, and the relation of chemistry and quantum mechanics. These implications are consistent with Kincaid’s model of unity and thus further support chemistry’s unity with quantum mechanics (as per Kincaid).