Paul Needham

Chemistry deals with substances and their transformations. School chemistry provides a picture of this in terms of small balls called atoms and ball-and-stick structures called molecules which, despite its crudity, has been taken to justifiably reflect a reductionist conception of macroscopic concepts like the chemical substances and chemical reactions. But with the recent interest in chemistry within the philosophy of science, an extensive and determined criticism has developed of the idea that the macroscopic world has been, or is likely to be, reduced to microscopic theory. From this perspective, it is of interest to see macroscopic ontology treated autonomously. I try to take a first few steps towards spelling this out. It involves recognising entities falling into two broad categories: continuants-things which can have different properties at different times — and processes — things whose temporal parts may have different features, but which themselves stand in contrast to continuants in this respect. The character of each and their interrelations depends on their mereological structure of parts, the exploration of which is one of the prime purposes of the paper.

This article was first published as “Notation atomique et hypothèses atomistiques”, Revue des questions scientifiques, 31 (1892), 391– 457. It is the second of a series of articles Duhem was to publish in the Catholic journal Revue des questions scientifiques, in which he presents his understanding of what can justifiably be said about the structure of chemical substances as captured by chemical formulas. The argument unfolds following a broadly historical development of events throughout the course of the century which was coming to a close as he wrote. He later reflected in his classic The Aim and Structure of Physical Theories – based in large part on articles which had appeared in the Revue – that “To give the history of a physical principle is at the same time to make a logical analysis of it” (p. 269). Logical analysis clearly dominates in the present article. The historical context was elaborated considerably in a later work, Le mixte et la combinaison chimique: Essai sur l’évolution d’une idée, which did not lead him to retract any aspect of his earlier position but provided a broader setting in which it could be elaborated. In particular, the Aristotelian influence, which is only hinted at here in some of the formulations (see especially the beginning of section VII) without mentioning Aristotle by name, is explicit in the later work, making Duhem’s own ontological conception a little clearer. A discussion of stereoisomerism, conspicuously absent in the present article, is also integrated into the later book. The same holds for Avogadro’s hypothesis.

In 1904 Joachim published an influential paper dealing with 'Aristotle's Conception of Chemical Combination' which has provided the basis of much more recent studies. About the same time, Duhem developed what he regarded as an essentially Aristotelian view of chemistry, based on his understanding of phenomenological thermodynamics. He does not present a detailed textual analysis, but rather emphasises certain general ideas. Joachim's classic paper contains obscurities which I have been unable to fathom and theses which do not seem to be fully explained, or which at least seem difficult for the modern reader to understand. An attempt is made here to provide a systematic account of the Aristotelian theory of the generation of substances by the mixing of elements by reconsidering Joachim's treatment in the light of the sort of points which most interested Duhem.The work described in this paper was undertaken with a view to providing a basis for presenting, evaluating and criticising Duhem's understanding of what was for him modern chemistry. This latter project will be taken up on another occasion. I hope the present paper will be of some value to a broader philosophical readership in so far as it provides a fairly clear conception of matter which might be called Aristotelian, even if it is not precisely Aristotle's, and raises certain clear problems of interpretation. It may also be of interest to historians of chemistry in suggesting an analysis of the old chemical notion of a mixt independent of atomic theories

This paper traces the principal thematic developments in Aristotle’s conception of chemical substance as they bear on the evolution of the notion into modern times. A line of speculation is indicated about the interpretation of elemental proportions clearly raised by Aristotle’s discussion but not pursued in his extant writings. Apart from its historical interest, Aristotle’s discussion of substance and mixture has been taken up in contemporary systematic philosophy (Fine 1995), where it is treated as at best only relevant to ordinary, everyday views. This approach gains support from the contention that such views have been superseded by the molecular conception of chemical substance developed in 19th century science and extolled by advocates of the Kripke-Putnam conception of microessentialism (Kripke 1980, Putnam 1975). Duhem (1902), who well understood what would now be called the macroscopic theory of thermodynamics and its relevance to chemistry, had a different view, and the present discussion is much influenced by him. Certainly, Aristotle’s view stands in need of modification in the light of the understanding of mixtures provided by Gibbs’ phase rule (Gibbs 1948). But with a certain weakening, a central Aristotelian claim about mixtures still has some bearing.

Gibbs’s phase rule treats mixtures by relating the number of independent variables governing their state to the numbers of phases and independent substances. For the case of a single substance, it provides a criterion of purity. But where more substances are involved, the notion of independent substance is less readily understood. Textbook writers sometimes use algebraic terminology in ways that are suggestive but cannot be taken as literally accurate. I suggest that a mereological interpretation applies to these cases, as it captures more concisely the insights underlying the use of algebraic ter- minology and illuminates the general notion of substance.

New perspectives on Pierre Duhem’s The aim and structure of physical theory Content Type Journal Article DOI 10.1007/s11016-010-9467-3 Authors Anastasios Brenner, Department of Philosophy, Paul Valéry University-Montpellier III, Route De Mende, 34199 Montpellier cedex 5, France Paul Needham, Department of Philosophy, University of Stockholm, 10691 Stockholm, Sweden David J. Stump, Department of Philosophy, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117, USA Robert Deltete, Department of Philosophy, Seattle University, 901 12th Avenue, Seattle, WA 98122-1090, USA Journal Metascience Online ISSN 1467-9981 Print ISSN 0815-0796 Journal Volume Volume 20 Journal Issue Volume 20, Number 1