What Is A Chemical Element?: A Collection of Essays by Chemists, Philosophers, Historians, and Educators

The Chemical Elements Philosophically Considered

I became interested in this book, "What is a Chemical Element?: A Collection of Essays by Chemists, Philosophers, Historians, and Educators" (2020) through my interest in philosophy. In particular, I had been reading about a form of philosophical naturalism, sometimes called "scientism" which attempts to reduce, both ontologically and epistemologically, reality and knowledge to the findings and methods of the sciences, especially physics. Philosophical naturalism and some of its alternatives are discussed in a recent book of essays, "Responses to Naturalism: Critical Perspectives from Idealism and Pragmatism" edited by philosopher Paul Giladi.

I had earlier read books by the chemist and philosopher Eric Scerri which seemed suggestive to me in approaching these issues of scientific naturalism in a technical way by a writer with a much more intensive knowledge of the sciences than that of most philosophers. Scerri is the co-editor of this book together with Elena Ghibaudi, a bioinorganic chemist and Assistant Professor of Chemistry at the University of Torino, Italy. Scerri and I have exchanged emails over the past several years, and he and Oxford University Press kindly sent me a review copy of this recent book.

This book is part of a relatively recent discipline called philosophy of chemistry in which chemists identify and explore the philosophical questions suggested by their studies. The philosophy of chemistry, of course, appeals to chemists and others with philosophical interests and not to all practitioners or students of chemistry. Through his many books and articles exploring the periodic table and what it teaches about the chemical elements and other matters in chemistry, Scerri is one of the leading figures in the philosophy of chemistry. He and Ghibaudi try to explain the importance of the field and of integrating philosophical questions with chemical studies in this book, which consists of fourteen essays by an international group of scholars who show great learning and thoughtfulness both in chemistry and in philosophical reflection.

Most students receive a rudimentary exposure to the chemical elements in high school. The nature of a chemical element is difficult to pin down. Each of the essays in this volume consider as a starting point the two-part definition of "element" propounded by the Gold Book of the International Union of Pure and Applied Chemistry (IUPAC) which reads:

"a species of atoms: all atoms with the same number of protons in the atomic nucleus

a pure chemical substance composed of atoms with the same number of protons in the atomic nucleus. Sometimes this concept is called the elementary substance as distinct from the chemical element as defined above, but mostly the term chemical element is used for both concepts."

The book explores the many issues raised by this definition in addition to its awkwardness. The first part phrases the definition in terms of atoms while the second begins with an apparently broader reference to a pure chemical substance. One part of the definition suggests reductiveness to simple substance while the other suggests elements as constituitive -- for example water is a compound of hydrogen and oxygen but the properties of these elements are lost when they combine to form water. Some of the volume's essays try to reconcile the two parts of the definition of element but most of the contributions to the volume suggest a troubling inconsistency between the two parts of the definition. Then too, some of the essays suggest that both prongs of the definition may be read naturalistically while other essays argue that the concept of element has a metaphysical or "transcendent" component that cannot be reduced to, say, a physical object such as a quantity of gold contained in a jar.

The essays explore the understanding of the nature of chemical element developed in the history of chemistry. The early competing views of Lavoisier and of the founder of the periodic table, Mendeleev, receive sustained attention in most of the essays. The essays also discuss the views of the 20th century chemist and philosopher Fritz Paneth who discussed the inconsistent naturalistic understandings of the nature of the chemical element and argued in favor of an overtly transcendent, metaphysical definition.

The essays also explore the views of many philosophers going back to the Pre-Socratics and to Aristotle. Some of the essays use the insights of theories of meaning and reference in analytic philosophy and the work of contemporary thinkers including Hilary Putnam. Kant is the historical philosopher receiving the most attention in this work. The First Critique is discussed in several essays and some go further to explore Kant's late writings on science. The work on elements of the twentieth century neo-Kantian philosopher Ernest Cassirer is explored as is the work of the more transcendental thinker Eduard von Hartmann who does not receive a great deal of attention from most contemporary philosophers.

The Introduction to the volume by Scerri and Ghibaudi gives a brief overview of the volume while Scerri's own essay "The Many Questions Raised by the Dual Concept of 'Element' explores and integrates the philosophical and chemical questions involved in understanding the nature of chemical elements and offers Scerri's own thoughts on their resolution. Ghibaudi co-authored the concluding essay, "The Dual Concept of the Chemical Element: Epistemic Aspects and Implications for Chemical Education." The philosophical discussions in this volume are combined with discussions of contemporary and historical issues in the science of chemistry, some of which presuppose a working knowledge of the discipline that most philosophers are unlikely to possess.

I am not a chemist but I was able to learn from and be challenged by this volume with my interest in philosophy. I was struck by the difference in approach between the Giladi volume mentioned early in this review and this book. In some ways, the philosophers and the chemists seem to by-pass one another even in their philosophical reflections. With a little digging, the approaches share some commonalities. I think the philosophers of chemistry as represented in this book would benefit from seeing how philosophers without a background in their discipline approach some of the broader questions they try to address. The philosophers in their turn would benefit from some particular knowledge of the sciences and of the work of scientists with a philosophical turn of mind, such as Scerri. This volume will reward reading by those with a serious interest in both philosophy and in the natural sciences.

Robin Friedman