Structure in Chemistry: A Preliminary Investigation

The concept of structure is central to chemistry. Chemists appeal to structure to explain why, for instance, carbon dioxide acts as a greenhouse gas, and why diamond is one of the hardest materials. Structure underpins chemical classification and nomenclature. It is also central to chemistry's relationships to other sciences like physics and biology. In spectroscopy, chemical structure and physical principles combine to explain how molecules interact with light and other radiation. Successful quantum-mechanical explanations of molecular structure are the reason why many philosophers see chemistry as in principle reducible to physics. Conversely, the distinction between the structure and function of biological molecules (e.g. 'messenger RNA') is the reason why many philosophers see biological explanation as irreducible.

Yet structure is the subject of foundational debate within chemistry. Chemists disagree over whether there is a sound physical understanding of the chemical bond, a central part of structural theory. If not, should the bond then be regarded as a mere figment of chemical theory, rather than an element of physical reality? Or does its success in unifying chemical knowledge mean that it must be taken more seriously?

This project will bring philosophers and chemists together to investigate the foundations of structure and the chemical bond, examining the explanatory role of structure within chemistry, and the extent to which such explanations can be grounded in physical theory.

This is an exploratory project focusing on an idea in science that is the subject of complex mathematical theories. Hence in the short term it is likely that the proposed research will primarily be of benefit to the academic community. In the longer term the research will also benefit university students and the wider general public.

1. The primary beneficiaries of the proposed research will be academic philosophers and historians of science, and philosophers more generally who work on questions with a bearing on science. The project will also be of benefit to scientists working in chemistry, physics and biology who are interested in the foundational questions underlying their work. This community will benefit by being made aware of the nature and significance of structure in chemistry, of different ideas of structure, of their development, and of debates concerning them.

2. The project will be of benefit to university students of philosophy, of science, and those who combine work in scientific and humanities disciplines by providing them with the opportunity for philosophical study of chemistry, a discipline which is neglected by philosophy in comparison to physics and biology. It will also provide them with an example of how humanities scholarship and science can be integrated, and how different scientific disciplines interact.

3. A significant section of the general public is interested in the workings, the findings and the theories of science. This community is well served already by the books, articles and television programmes that popularise particular scientific findings across physics, chemistry and biology. A prominent part of this material has made the scientifically literate public aware of foundational debates within physics (concerning for instance the different interpretations of quantum mechanics), and biology (concerning for instance the different interpretations of evolutionary theory). In this genre chemistry and its theories are less prominent. The benefit of the proposed research will be to make the public more aware of the nature and significance of debates within chemistry concerning its fundamental ideas, and aware of the fact that these ideas, which may otherwise be taken for granted, are contested. In so far as chemistry is perceived as a practical science, the project will increase its profile as a discipline that addresses issues that are of abiding intellectual interest and debate.