Realism, history and the quantum theory: Philosophical and historical arguments for realism as a methodological thesis.

Scientific realists and non-realists disagree over the reach of scientific knowledge: does it extend beyond the observational realm. Intuitions about abductive inferences are at the heart of many realist positions, but are brought into question by the non-realists' contention that theories are underdetermined by data, and the alleged circularity of realist attempts to show that such inferences are reliable. Some realists have tried to circumvent this problem by constructing methodological arguments for realism: if realism is embedded in scientific practice, the realist's picture of science might provide the best explanation of scientific success. Some non-realists reply by again pointing to the circularity of this strategy, which relies, again, on an abductive inference. Others deny that scientists do adopt realist stances. A methodological realist position is constructed: realist constraints on the acceptance and pursuit of theories-for instance requirements of intertheoretic coherence, and the avoidance of ad hoc explanation-have often contributed to progress in science. The position is immune to non-realist worries about the circularity of realist arguments, for it is a thesis about how science is practised, not the kind of knowledge it provides. The argument is pursued within a diachronic account of theory appraisal: Imre Lakatos' methodology of scientific research programmes (MSRP) examines the principles that govern the construction of theories, and provides criteria-achievement of progress-for the appraisal of research programmes. Although Lakatos may have seen these selection criteria, when fulfilled, as symptoms of something else-the fulfilment in the theory's development of some ideal of scientific honesty-achievement of Lakatosian progress can Serve as an end in itself. The realist methods mentioned in the last paragraph are then appraised as means to this end. Since the position has a methodological formulation and background, it is applied as a historical thesis to case studies in line with Lakatos' metamethodology. These comprise two explanatory forays into history: the consistency of Bohr's 1913 model of the atom, and the construction by Heisenberg and Schrodinger of the two original formulations of quantum mechanics. There follows one contemporary application: the construction of explanations in quantum chemistry using approximate models of molecules

Elements and (first) principles in chemistry

The first principle of chemical composition is that elements are actually present in their compounds. It is a golden thread running through the history of compositional thinking in chemistry since before the chemical revolution. Opposed to this principle, which I call Actually Present Elements (APE), is the idea that elements are merely potentially present in their compounds: although not actually present, it is possible to recover them. In this paper I follow that golden thread, and then discuss the status of APE itself: is it true? What arguments were there for it, and when? I argue that APE is a metaphysical principle, albeit at a lower level of generality and abstraction than the term ‘metaphysical’ usually suggests. I critically examine a range of different views on how metaphysical principles might be involved in research programmes in empirical science, and conclude by endorsing Elie Zahar’s view that metaphysical principles such as APE are to be found at the very heart of science. Moreover, they can be recipients of empirical support just like other parts of scientific theory

Structure, scale and emergence

In this paper I consider the structures that chemists and physicists attribute at the molecular scale to substances and materials of various kinds, and how they relate to structures and processes at other scales. I argue that the structure of a substance is the set of properties and relations which are preserved across all the conditions in which it can be said to exist. In short, structure is abstraction. On the basis of this view, and using concrete examples, I argue that structures, and therefore the chemical substances and other materials to which they are essential, are emergent. Firstly, structures themselves are scale-dependent because they can only exist within certain physical conditions, and a single substance may have different structures at different scales (of length, time and energy). Secondly, the distinctness of both substances and structures is a scale-dependent relationship: above a certain point, two distinct possibilities may become one. Thirdly, the necessary conditions for composition, for both substances and molecular species, are scale-dependent. To know whether a group of nuclei and electrons form a molecule it is not enough to consider energy alone: one also has to know about their environment and the lifetime over which the group robustly hangs together

Trusting Atoms

antiquity to the present day. This collection covers the richness of its history, starting with how the Ancient Greeks came to assume the existence of atoms and concluding with contemporary metaphysical debates about structure, time and reality. Focusing on important moments in the history of human thought when the debate about atomism was particularly flourishing and transformative for the scientific and philosophical spirit of the time, this collection covers: - The discovery of atomism in ancient philosophy - Ancient non-Western, Arabic and late Medieval thought - The Renaissance, when alongside the re-discovery of ancient thought, atomism as a doctrine of mind and matter was brandished by Leibniz and Spinoza - The history and philosophy of chemistry after Dalton - Logical atomism in early analytic philosophy, with Russell and Wittgenstein - Atomism in quantum physics. Featuring 35 previously unpublished essays, written especially for the collection by leading and younger scholars, this valuable collection reveals the development of one of philosophy's central doctrines across 2,000 years and within a broad range of philosophical traditions

Structure, essence and existence in chemistry

Philosophers have often debated the truth of microstructural essentialism about chemical substances: whether or not the structure of a chemical substance at the molecular scale is what makes it the substance it is. Oddly they have tended to pursue this debate without identifying what a structure is, and with some confusion and about what a chemical substance is. In this paper I draw on chemistry to rectify those omissions, providing a pluralist account of structure, clarifying what (according to chemistry) a chemical substance is and defending microstructural essentialism, as I understand that position. I then give an account of the existence of composite substances and objects in chemistry, an issue that goes back to Aristotle

Right out of the box: How to situate metaphysics of science in relation to other metaphysical approaches

Several advocates of the lively field of "metaphysics of science" have recently argued that a naturalistic metaphysics should be based solely on current science, and that it should replace more traditional, intuition-based, forms of metaphysics. The aim of the present paper is to assess that claim by examining the relations between metaphysics of science and general metaphysics. We show that the current metaphysical battlefield is richer and more complex than a simple dichotomy between "metaphysics of science" and "traditional metaphysics", and that it should instead be understood as a three dimensional "box", with one axis distinguishing "descriptive metaphysics" from "revisionary metaphysics," a second axis distinguishing a priori from a posteriori metaphysics, and a third axis distinguishing "commonsense metaphysics", "traditional metaphysics" and "metaphysics of science." We use this three-dimensional figure to shed light on the project of current metaphysics of science, and to demonstrate that, in many instances, the target of that project is not defined with enough precision and clarity