Philosophy of Chemistry

Is Leibnizian dynamics the New Physics sought in his youth to provide a solution to the problem of body unity/composition? This question can only be answered tentatively. The thesis that I will develop in this second part is that chemical-combinatoria project is not complete without some ideas of dynamics. The idea of form, which since the early Leibniz’s philosophy is projected to give a foundation to the corpuscular theory, only reaches this objective with the theory of conspiring movements that Leibniz (...) develops as the last phase of his dynamics. Within this general objective, this second part develops three secondary issues of importance: Leibniz’s emergent and realistic position, his theory of compounds and the interpretation of the Combinatoria or Characteristica project as a science of forms. (shrink)

Recently, philosophers have come forth with approaches to chemistry based on its actual practice, imparting to it a proper aim and character of its own. These approaches add to the currently growing movement of pluralist philosophies of science. We draw on recent pluralist accounts from chemistry and analyse three notions from modern chemical practice and theory in terms of these accounts, in order to complement the so far more general pluralist approaches with specific evidence. Our survey reveals that the concept (...) of element indicates conceptual pluralisms in chemistry. that electronegativity illustrates methodological pluralism in determining one and the same concept, and that acidity is an instance of plurality hidden behind ‘one notion’. (shrink)

Electron redistribution is the cornerstone of our understanding of chemical reactivity. For the vast majority of organic reactions electrons are assumed to move in pairs providing explanatory mechanisms through the generation of intermediate structures. But for many transformations these discrete steps are idealized constructs, involving intermediates assumed but not empirically justified. This unitary perspective predicated on the curved arrow formalism has resulted in the scenario where for many organic transformations our supposed understanding far surpasses our growing knowledge. Reformulating organic mechanisms (...) to include single electron transfer as a component of, or an alternative to, the prevailing iconic descriptions can provide for a more empirically adequate mechanistic description. In addition using the language of SET presents an opportunity to unify mechanistic concepts under a common donor/acceptor framework. (shrink)

All suggested notions of reduction of two scientific theories are critically reviewed and analyzed. In particular those applied to the case of the alleged reduction of Chemistry to Quantum mechanics are examined. Since it is recognized that the weakness of this field of research is the lack of a definition of a scientific theory, it is suggested that a scientific theory is characterized by two choices regarding two dichotomies, that is, the kind of mathematics and the kind of logic. According (...) to this view a reduction is only possible between two theories in which the same choices are shared. As a consequence, only one case of reduction in the history of physics is recognized: physical optics to electromagnetism, a case that is commonly accepted. The other cases of claimed reductions are recognized as impossible, owing to the different choices of the two theories at issue and hence the radical variations in meaning of their shared basic notions. In particular, the claimed reduction of Chemistry to Quantum mechanics is disproved in detail. (shrink)

Much has been said about the accuracy of the famous predictions of the Russian chemist Dmitrii Ivanovich Mendeleev, but far less has been written on how he made his predictions. Here we offer an explanation on how Mendeleev used his periodic system to predict both physical and chemical properties of little-known and entirely unknown chemical elements. We argue that there seems to be compelling evidence in favour of Mendeleev genuinely relying on his periodic system in the course of issuing his (...) predictions—a point recently contested by Woody Science after the practice turn in the philosophy, history, and social studies of science, Routledge, Abington, 2014). In particular, by using the known properties of a number of near neighbours of the three entirely unknown elements, we seek to show how the very format of his table enabled it to function as a powerful tool for Mendeleev in arriving at his predicted values. We suggest that Mendeleev’s use of the periodic system in making his prediction gives an illuminative example of what Woody calls “theoretical practices” in science. (shrink)

There has been plenty of empirical evidence which shows that the single-particle picture holds to a good approximation in atomic nuclei. In this picture, protons and neutrons move independently inside a mean-field potential generated by an interaction among the nucleons. This leads to the concept of nuclear shells, similar to the electronic shells in atoms. In particular, the magic numbers due to closures of the nucleonic shells, corresponding to noble gases in elements, have been known to play an important role (...) in nuclear physics. Here we propose a periodic table for atomic nuclei, in which the elements are arranged according to the known nucleonic shells. The nuclear periodic table clearly indicates that nuclei in the vicinity of the magic numbers can be understood in terms of a shell closure with one or two additional nucleons or nucleon holes, while nuclei far from the magic numbers are characterized by nuclear deformation. (shrink)

This article discusses the mathematizing of the chemical periodic system as a grid, which leads to a quadratic function or “binódica function” formed by pairs of periods or binodos. We describe the periodic law as an increasing function of the principal quantum number. It works subject to the dialectical laws that generate; first: gradual quantitative changes:, with “duplication” of periods:. Second: radical quantitative changes:, with the emergence of new quantum transitions, growth and a change in the format of the binodos. (...) We use analytical and graphic methods to mathematize Mendeleev’s law, making the size of the binodos and the continuous series depend on the number of the binode, which is the same quantum number. Likewise, we show a graphic representation, in 2D, of a continuous and self-similar spiral function of the elements, in a geometric growth pattern. (shrink)

The periodic table can be simply demarcated into four classes of metal and four classes of nonmetal. Such a treatment has been obstructed by the traditional view of metalloids as in-between elements; understandable but needless boundary squabbles; and a group-by-group view of the reactive nonmetals. Setting aside these limiting notions reveals some interesting patterns and facilitates teaching and learning the periodic table.

In the original publication of the article under the Acknowledgements section, a contributor name was missed out. The corrected statement should read as follows.

Electronegativity is an important physico-chemical concept to study the chemical structure and reactivity. Although, the conundrum related to measurement of electronegativity still persists. In view of this fact, a simple yet rigorous scale of electronegativity, invoking an inverse relationship with atomic nucleophilicity index, has been proposed for 103 elements of the periodic table. The computed data follows periodicity distinctly satisfying all the sine qua non of a standard scale of electronegativity. Further, electronegativity values display a sound similarity with the standard (...) electronegativity scales validating the suitability of the proposed model. Molecular electronegativities of some polyatomic molecules have also been calculated using the proposed scale of electronegativity.Graphic. (shrink)

A 4-dimensional periodic table of chemical elements is presented. The 120 elements in the n = 8 system are located on vertices of a 4D-cubic lattice and specified by Cartesian coordinates based on the four quantum numbers. Each quantum number is represented by a vector along a different spatial direction in 4D Euclidean space. The 4D PT has a fixed topology governed by Euler–Poincare-type equation and the chemical elements have a fixed connectivity with neighboring elements within the 4D PT. Various (...) geometric transformations by rotations and elongations of vectors enable morphing of one PT to another in a continuum while preserving the 4D topology. The 4D structure exhibits principles of complementarity and zero-cyclic sum in chemical elements. Complementarity enables the extension to n = 9 elements and beyond. The 4D PT of elements extends to isotopes and also to molecules and compounds with the same underlying principles. (shrink)

The concepts of molecular structure and molecular shape are ubiquitous in the chemical literature, where they are often taken as synonyms, with unavoidable drawbacks in chemistry teaching. A third concept, molecular topology, is less frequent but it is a reference term in molecular research domains such as Quantitative Structure–Activity Relationships. The present paper proposes an epistemological analysis of these three notions, aimed at clarifying the nature of their relationship, as well as the contiguities and differences between them. At first, we (...) discuss the various acceptations of the terms molecular structure and molecular shape. Then, we examine some crucial milestones in the history of these concepts and we analyse the relationship between structure, shape and topology from an epistemological viewpoint. We point out the distinguishing features of each concept and we show that their semantic openness, that may be fruitful in a specialized context, turns into a source of incoherence and inaccuracy in the teaching context, fostered by the misleading use of these terms made by textbooks. Eventually, we propose a criterion fit to discriminate between the conceptual domains of molecular shape, molecular structure and molecular topology. (shrink)

This paper considers the nature of a curriculum as presented in formal curriculum documents, and the inherent difficulties of representing formal disciplinary knowledge in a prescription for teaching and learning. The general points are illustrated by examining aspects of a specific example, taken from the chemistry subject content included in the science programmes of study that are part of the National Curriculum in England. In particular, it is suggested that some statements in the official curriculum document are problematic if we (...) expect a curriculum to represent canonical disciplinary knowledge in an unambiguous and authentic manner. The paper examines the example of the requirement for English school children to be taught that chemical reactions take place in only three different ways and considers how this might be interpreted in terms of canonical chemistry and within the wider context of other curriculum statements, in order to make sense of neutralisation and precipitation reactions. It is argued that although target knowledge that is set out as the focus of teaching and learning cannot be identical to disciplinary knowledge, the English National Curriculum offers a representation of chemistry which distorts and confuses canonical ideas. It is suggested that the process of representing the disciplinary knowledge of chemistry as curriculum specifications is worthy of more scholarly attention. (shrink)

This paper considers the nature of a curriculum as presented in formal curriculum documents, and the inherent difficulties of representing formal disciplinary knowledge in a prescription for teaching and learning. The general points are illustrated by examining aspects of a specific example, taken from the chemistry subject content included in the science programmes of study that are part of the National Curriculum in England. In particular, it is suggested that some statements in the official curriculum document are problematic if we (...) expect a curriculum to represent canonical disciplinary knowledge in an unambiguous and authentic manner. The paper examines the example of the requirement for English school children to be taught that chemical reactions take place in only three different ways and considers how this might be interpreted in terms of canonical chemistry and within the wider context of other curriculum statements, in order to make sense of neutralisation and precipitation reactions. It is argued that although target knowledge that is set out as the focus of teaching and learning cannot be identical to disciplinary knowledge, the English National Curriculum offers a representation of chemistry which distorts and confuses canonical ideas. It is suggested that the process of representing the disciplinary knowledge of chemistry as curriculum specifications is worthy of more scholarly attention. (shrink)

One of the foundational problems of biochemistry concerns the conceptualisation of the relationship between the composition, structure and function of macromolecules like proteins. Part of the recent philosophical literature displays a reductionist bias, that is, the endorsement of a form of microstructuralism mirroring an out-dated biochemical conceptualisation. We shall argue that such microstructuralist approaches are ultimately committed to a potentialist form of micro-predeterminism whereby the macrostructure and function of proteins is accounted for solely in terms of the intrinsic properties and (...) potentialities of the components of the primary structure as if they were self-contained or essentially immutable entities. We shall instead suggest that a conceptualisation of the relationship between proteins’ composition, structure and function consistent with contemporary biochemical practice should account also for the causal role of the cellular, organismal and environmental relations in protein development. The analysis of the folding process we propose suggests that microstructure-laden reductionist approaches are ontologically indefensible. Rather than a potentialist form of micro-predeterminism, our analysis ultimately supports a relational-construction-based view of protein development and potentialities formation, which requires an indispensable analysis of the dynamical interplay between the micro-level of the parts and the macro-level of the relational structures of their systems. (shrink)

While temporal considerations are of prime importance for chemical reactions, as well as for molecular stability, most chemical concepts are not explicitly formulated on a diachronic basis. It will be argued here that a formulation explicitly incorporating temporal and epistemological considerations enables us to treat chemical reactions and chemical substances on ontologically equivalent terms, instead of assigning a more fundamental status to the latter. After all, in collision theory, a chemical substance is just a collision complex that takes too long. (...) How long qualifies as “too long”, and “too long” in relation to what, are crucial questions that distinguish chemical substances from chemical reactions, and reversible reactions from irreversible ones, thereby introducing anthropocentric considerations into these distinctions. Too long for a lab chemist is very different from too long for an astrochemist studying chemical reactions between chemical substances in inter-stellar space on cosmological timescales. Examining several physical and chemical properties on the basis of which chemical substances are distinguished from one another, the role of temporal and anthropocentric considerations in defining molecular properties is emphasized. I conclude with some observations on the much-debated reduction of chemistry to other disciplines, arguing that such reduction depends on our aesthetic choices as to what kinds of observations demand explanation, and what kinds of explanation are acceptable. (shrink)

The history of the diffusion and confirmation of Mendeleev’s periodic table of elements has proven to be a challenging testbed for contemporary philosophical debates on the role of predictions in science. More than ten years of fruitful literature came after Scerri and Worrall :407–452, 2001) versus Maher and Lipton ; nevertheless, such a long-lasting debate left quite a few open questions. The aim of this contribution is to go through the various cases that emerged during the debate, in an effort (...) to explain them coherently in a weak predictivist perspective. Maher’s early account—according to which the astounding success of the major predictions alone was enough to explain the confirmation of the periodic table—can now be replaced by a more balanced and thorough picture, where both predictions and accommodations do weight. (shrink)

In recent publications, Harré and Llored Challenges of cultural psychology, Routledge, London, pp 189–206, 2018a; Philosophy, 93:167–186, 2018b; The analysis of practices, Cambridge Scholars Publishing, Newcastle upon Tyne, 2019) take the role of philosophy of science as a digging out of the ‘hinges’, that are the tacit elements of a discipline. In this perspective, the philosophy of chemistry consists, at least partly, in making explicit the hinges on which chemistry turns and in examining their origins and logical status. In this (...) paper, we propose to query Harré and Llored’s research approach in the case study of the element chlorine. Whereas most early nineteenth-century textbooks define the element as the endpoint of chemical decomposition, the controversy surrounding the element chlorine reveals implicit criteria that surpass operational indivisibility. From 1810 onwards, Davy argued that chlorine was a simple substance; yet, even though it had been known to be indecomposable using the strongest instruments available, the widespread acceptance of chlorine took until 1816–1818. The main factor that contributed to the resolution of the debate was the discovery of iodine, an analogous element which provided new theoretical coherence between explanations of different phenomena :247–258, 1959). Thus, the idea that elements should qualitatively resemble each other is an implicit belief which appears to have been shared by many prominent chemists of the time, despite the fact that it was not stated as part of the definition of the chemical element. Could we assert that this idea was a ‘hinge’ around which the notion of chemical element revolved? Our talk will answer this question. (shrink)

The importance of watching and understanding color of chemical compounds and linking it to diverse physical and chemical properties is illustrated here using transition metal oxides at the highest achievable oxidation state of a metal. Analyses are based on qualitative thinking supported by Molecular Orbital theory in its simplest implementation.Graphic abstract.

This essay critically considers the issue of natural kind essentialism. More specifically, the essay critically probes the philosophical use of chemical examples to support realism about natural kinds. My simple contention is that the natural kind debate can be understood in terms of two different cultures of academic production. These two cultures will be conceptualized using Thomas Kasulis’s distinction between intimacy and integrity as cultural orientations. Acknowledging Kasulis’s contention that, “What is foreground in one culture may be background in another”, (...) it may very well be the case that philosophers writing about chemistry place chemical practice in the background, thereby adopting the orientation of integrity. Chemists and philosophers of chemistry, on the other hand, place chemical practice at the foreground of their work, thereby adopting the orientation of intimacy. Because the intimacy orientation is grounded in chemical practice, it is preferable to the integrity orientation. Understanding the natural kinds debate from this perspective highlights the fact that the misuse of chemical examples by certain philosophers is informed by an orientation of detachment from actual chemical practice. This underscores the importance of an intimate understanding of chemical practice when deploying chemical examples in the context of philosophical discussions about ontology and metaphysics. (shrink)

The time-honored questions concerning the meaning and significance of life should be discussed not only in the light of various philosophical and literary considerations but also from the natural scientific perspectives as human beings are conditioned parts of nature as a whole. Hence, in this paper, I discuss these questions from the perspectives of two major and universal scientific fields, namely, generalized crystallography and quantum mechanics. On the philosophical grounds, the question of the meaning and, especially, the significance of life (...) should be focused on the assumption that each human being is a singular individual whose significance is universal. Such a philosophical approach is compatible with the two above-mentioned natural scientific aspects. (shrink)

The Timaeus is the dialogue that was for many centuries the most influential of Plato’s works. Among its readers we find Descartes, Boyle, Kepler and Heisenberg. In the first division of Timaeus Plato deals with the theory of celestial motion, in the second he presents us with the first mathematical theory of the structure of matter. Here, in a gigantic step forward with respect to the preceding Democritean atomistic theory with its unalterable micro-entities, he introduces the intertransformability of elementary corpuscles (...) and with that the first “chemical” reactions in history. Plato’s geometrical interpretation of Empedocles’ elements and his geometrical atomism is described at the molecular, atomic and sub-atomic level. The “chemical” reactions reported in Timaeus are written in the enlightening chemical symbolism, analogies with modern chemistry are noticed throughout. (shrink)

The practice of theoretical research in chemistry largely consists in the construction of models without which experimentation would be impossible. The best-known theoretical models in chemistry are those of the molecular structures of chemical compounds. What is the correspondence between these models and the unobservable entities that they are meant to explain? What is the ontological status of molecular models? The anti-realists question the basis of the realists’ belief in these entities and the truth claims regarding them. Ultimately, the realist/anti-realist (...) debate points to the question of the scope of scientific knowledge. In this paper, I shall show that the description of natural entities offered by the contemporary scientific worldview reveals that molecular modeling presupposes a realistic epistemology that recognizes the limits of scientific objectification. (shrink)

Since molecules are inaccessible to immediate observation, our conception of the molecule is brought about by transdiction which entails invention of various transcendental ideas. In organic chemistry we think that molecules consist of atoms, bonds, functional groups, etc. This is, however, not the unique description of the molecule as is shown by quantum mechanical calculations, for example. Then, what description represents the real molecule? Before asking this question, we have to consider what the real molecule is in the first place. (...) Constructive realism distinguishes our cognitive world and the world just given, and claims that we should accept the former as reality. Understanding our cognitive world is possible only through construction of micro-worlds. Atoms, bonds, functional groups, etc., are micro-worlds which make sense in a theoretical framework of organic chemistry. In this study we translate a micro-world to an affordance and paraphrase it as a context-relative dispositional attribute of an {agent-world} complex. Then, we can understand that it is what we take as molecular structure, not what might be out there to be found, that we should accept as reality. Excluding metaphysical fictions from scientific arguments, constructive realism makes science a meaningful activity. Constructive realism claims that, for getting knowledge of the world, we have to integrate information into our own linguistic frame, i.e., to translate it. Strangification is a technique of intentionally taking an accepted proposition out of one scientific system and putting it into a completely different context. As is the case with translation, strangification brings about deeper understanding of philosophical as well as scientific grounds on which the proposition system holds. We apply this method to molecular structure and reveal that it is an ingenious model to describe molecular behavior in multi-molecular systems with strong interactions between molecules. Information provided by strangification is essential to claim the legitimacy of a proposition system. As far as strangification is properly applied, relativism is irrelevant to constructive realism. (shrink)

The paper deals with the philosophy of science and technology from a new perspective. The analysis connects closely to the novel approach to scientific research called practical realism of the late Estonian philosopher of science and chemistry Rein Vihalemm. From his perspective, science is not only theoretical but even more clearly a practical activity. This kind of practice-based approach puts chemistry rather than physics into the position of the most typical science as chemistry has a dual character resting on both (...) constructive-hypothetico-deductive and classifying-historico-descriptive types of cognition. Chemists deal with finding out the laws of nature just like the physicists do. However, in addition to this chemistry deals with substances or stuff that is rather an activity typical to natural history. The analysis of the dual character of chemistry brings forward the need to analyse philosophically also the reasons why physics has held the position of the model science so far. The problem unfolds in the context of practical realism. However, some earlier observations concerning the dual character of chemistry influenced us as well, i.e. by Friedrich Paneth, Michael Polanyi and Edward Caldin. More recently, Bernadette Bensaude-Vincent and Jonathan Simon have given their own explanation of why and how chemistry has a dual character. From their perspective, chemistry is a perfect technical science as it aims at applications, literally at producing something new. Bensaude-Vincent and Simon call their approach operational realism. The latter, however, does not differ from practical realism. (shrink)

An Example of Teaching of Chemistry Before and After Mendeleev’s 1869 Periodic Table of Elements is presented. Prior to Mendeleev’s publication in 1869, only 63 elements were known. The ensuing discovery of the electron and the correspondence of the number of electrons to equivalent weight and atomic number is of singular importance to the impact of the Periodic Table of Elements and the way modern chemistry is taught. Without the identity of the electron and its alliance to atomic number, modern (...) teaching of chemistry would be very different. Without it concepts of electronic configuration, oxidation and reduction, polarization, intermolecular interactions, types of bonding, Lewis acid/base definition, etc. would disappear in our vernacular. Thus, we trace the origin of the electron. (shrink)

By moving away from the traditional reductionist reading of the quantum theory of atoms in molecules, in this paper we analyze the role played by QTAIM in the relationship between molecular chemistry and quantum mechanics from an emergentist perspective. In particular, we show that such a relationship involves two steps: an intra-domain emergence and an inter-domain emergence. Intra-domain emergence, internal to quantum mechanics, results from the fact that the electron density, from which all the other QTAIM’s concepts are defined, arises (...) from the wavefunction as a coarse-grained magnitude. Inter-domain emergence involves an analogical link, a mapping, between QTAIM’s entities, such as topological atoms and bond paths, and the entities that populate the molecular-chemistry domain, such as chemical atoms and chemical bonds. (shrink)

The dissemination of models across disciplinary lines has become a phenomenon of interest to philosophers of science. To account for this phenomenon, philosophers have invented two units of analysis. The first identifies to the thing that transfers, model templates. The second identifies the thing to which transferable templates apply, landing zones. There exists a dynamic between the thing that is transferred and the thing to which transferrable templates apply. The use of a transferable template in a new domain requires reconception (...) of domain-specific phenomena. This paper examines two cases of model transfer, the use of the ideal gas law in biology by R.A. Fisher and the use of the virial theorem in chemistry by Richard Bader. These two stories of model transfer in biology and chemistry indicate a dimension to conceptual progress related to this dynamic. Using discourse on model transfer affords philosophers a novel approach for depicting the invention of, for instance, chemical concepts and resulting disputes. (shrink)

Whom should we credit for the discovery of isotopes? The first suggestion of an idea, the first experimental proof, or the development of a new method that clearly reveals the isotopes? Strömholm and Svedberg, Fajans and Soddy interpreted patterns of radioactive decay, which became confirmed theory on the solid basis of the very accurate atomic weight determinations by Richards and his coworkers. The mass spectrograph measurements by Aston provided major extension of the concept of isotopes to much of the rest (...) of the periodic table. Thus, Strömholm and Svedberg, Fajans and Soddy provided an idea, which Richards proved, and Aston made generally useful. Richards should be listed along with Fajans, Soddy, and Aston for fundamental contributions to establishing isotopes as part of the modern language of science. As much credit should be given to the experimental proof as to the suggestion or naming of the concept. (shrink)

What chemists take as molecular structure is a theoretical construct based on the concepts of chemical bond, atoms in molecules, etc. and hence it should be distinguished from tangible structures around us. The practical adequacy of it has been demonstrated by the established method of retro-synthetic analysis, for instance. But it is not derived a priori from quantum mechanical treatments of the molecule and criticized for being irrelevant to the reality of the molecule. There is persistent skepticism about it. The (...) present study aims to overcome this skepticism by having recourse to the concepts of affordance and phenomenal field. The basic idea of our approach is suggested by the following statement of Niels Bohr: ‘evidence obtained under different experimental conditions cannot be comprehended within a single picture but must be regarded as complementary in the sense that only the totality of the phenomena exhausts the possible information about the objects’. This implies that we should take account of a context in which the cognition of a fact arises when we think about human activities including science. This can be realized by invoking affordances of a complex such as {agent, devices, methods, substances, surroundings}. That is to say, affordances are context-relative dispositional attributes of {agent-material world} complexes as is asserted by Harré and Llored. The phenomenal field is a conceptual device which schematizes the contextual aspect of affordance and, more importantly, serves as a link between the concept of affordance and Kant’s theory of knowledge, by which alone affordances are realized as the dispositional properties of {agent-material world} complexes. Because affordances become actualized in various phenomenal fields, affordances of one and the same object may well be distinct from one another. In conclusion we can take that molecular structure is the affordance of a complex that includes a chemist who is engaged in organic synthesis, whereas a quantum mechanical picture of the molecule may be one of the possible affordances of a complex that includes a quantum chemist who cares about electronic states of the molecule. (shrink)

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. 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. (shrink)

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. 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. (shrink)

I present a formal language that imposes a structure on processes in macro-chemistry. Each symbol in the language invites a type of analysis that is carried out either by looking into the semantics if the language or by looking at the context. Every formal language has assumptions underlying it. The assumptions made in developing the formal language are meant to help with conceptual analysis by inviting certain types of question.

What chemists take as molecular structure is a theoretical construct based on the concepts of chemical bond, atoms in molecules, etc. and hence it should be distinguished from tangible structures around us. The practical adequacy of it has been demonstrated by the established method of retro-synthetic analysis, for instance. But it is not derived a priori from quantum mechanical treatments of the molecule and criticized for being irrelevant to the reality of the molecule. There is persistent skepticism about it. The (...) present study aims to overcome this skepticism by having recourse to the concepts of affordance and phenomenal field. The basic idea of our approach is suggested by the following statement of Niels Bohr: ‘evidence obtained under different experimental conditions cannot be comprehended within a single picture but must be regarded as complementary in the sense that only the totality of the phenomena exhausts the possible information about the objects’. This implies that we should take account of a context in which the cognition of a fact arises when we think about human activities including science. This can be realized by invoking affordances of a complex such as {agent, devices, methods, substances, surroundings}. That is to say, affordances are context-relative dispositional attributes of {agent-material world} complexes as is asserted by Harré and Llored. The phenomenal field is a conceptual device which schematizes the contextual aspect of affordance and, more importantly, serves as a link between the concept of affordance and Kant’s theory of knowledge, by which alone affordances are realized as the dispositional properties of {agent-material world} complexes. Because affordances become actualized in various phenomenal fields, affordances of one and the same object may well be distinct from one another. In conclusion we can take that molecular structure is the affordance of a complex that includes a chemist who is engaged in organic synthesis, whereas a quantum mechanical picture of the molecule may be one of the possible affordances of a complex that includes a quantum chemist who cares about electronic states of the molecule. (shrink)

What chemists take as molecular structure is a theoretical construct based on the concepts of chemical bond, atoms in molecules, etc. and hence it should be distinguished from tangible structures around us. The practical adequacy of it has been demonstrated by the established method of retro-synthetic analysis, for instance. But it is not derived a priori from quantum mechanical treatments of the molecule and criticized for being irrelevant to the reality of the molecule. There is persistent skepticism about it. The (...) present study aims to overcome this skepticism by having recourse to the concepts of affordance and phenomenal field. The basic idea of our approach is suggested by the following statement of Niels Bohr: ‘evidence obtained under different experimental conditions cannot be comprehended within a single picture but must be regarded as complementary in the sense that only the totality of the phenomena exhausts the possible information about the objects’. This implies that we should take account of a context in which the cognition of a fact arises when we think about human activities including science. This can be realized by invoking affordances of a complex such as {agent, devices, methods, substances, surroundings}. That is to say, affordances are context-relative dispositional attributes of {agent-material world} complexes as is asserted by Harré and Llored. The phenomenal field is a conceptual device which schematizes the contextual aspect of affordance and, more importantly, serves as a link between the concept of affordance and Kant’s theory of knowledge, by which alone affordances are realized as the dispositional properties of {agent-material world} complexes. Because affordances become actualized in various phenomenal fields, affordances of one and the same object may well be distinct from one another. In conclusion we can take that molecular structure is the affordance of a complex that includes a chemist who is engaged in organic synthesis, whereas a quantum mechanical picture of the molecule may be one of the possible affordances of a complex that includes a quantum chemist who cares about electronic states of the molecule. (shrink)

Whom should we credit for the discovery of isotopes? The first suggestion of an idea, the first experimental proof, or the development of a new method that clearly reveals the isotopes? Strömholm and Svedberg, Fajans and Soddy interpreted patterns of radioactive decay, which became confirmed theory on the solid basis of the very accurate atomic weight determinations by Richards and his coworkers. The mass spectrograph measurements by Aston provided major extension of the concept of isotopes to much of the rest (...) of the periodic table. Thus, Strömholm and Svedberg, Fajans and Soddy provided an idea, which Richards proved, and Aston made generally useful. Richards should be listed along with Fajans, Soddy, and Aston for fundamental contributions to establishing isotopes as part of the modern language of science. As much credit should be given to the experimental proof as to the suggestion or naming of the concept. (shrink)

I present a formal language that imposes a structure on processes in macro-chemistry. Each symbol in the language invites a type of analysis that is carried out either by looking into the semantics if the language or by looking at the context. Every formal language has assumptions underlying it. The assumptions made in developing the formal language are meant to help with conceptual analysis by inviting certain types of question.

The dissemination of models across disciplinary lines has become a phenomenon of interest to philosophers of science. To account for this phenomenon, philosophers have invented two units of analysis. The first identifies to the thing that transfers, model templates. The second identifies the thing to which transferable templates apply, landing zones. There exists a dynamic between the thing that is transferred and the thing to which transferrable templates apply. The use of a transferable template in a new domain requires reconception (...) of domain-specific phenomena. This paper examines two cases of model transfer, the use of the ideal gas law in biology by R.A. Fisher and the use of the virial theorem in chemistry by Richard Bader. These two stories of model transfer in biology and chemistry indicate a dimension to conceptual progress related to this dynamic. Using discourse on model transfer affords philosophers a novel approach for depicting the invention of, for instance, chemical concepts and resulting disputes. (shrink)

The so-called ‘redintegration experiment’ is traditionally at the center of the comments on the supposed Boyle/Spinoza controversy. A. Clericuzio influentially argued in his publications that, in De nitro, Boyle accounted for the ‘redintegration’ of saltpeter on the grounds of the chemical properties of corpuscles and “did not make any attempt to deduce them from mechanical principles”. By way of contrast, this paper argues that with his De nitro Boyle wanted to illustrate and promote his new corpuscular or mechanical philosophy, and (...) that he made significant attempts to explain the phenomena in terms of mechanical qualities. Boyle had borrowed the ‘redintegration experiment’ from R. Glauber and used it in an attempt to demonstrate that his philosophy was superior to the Peripatetic and Paracelsian theory. Consequently, Clericuzio’s characterization of the Boyle/Spinoza controversy as a discussion between a strict mechanical philosopher and a chemist is problematic and a wider view of Spinoza’s interpretation and its context gives a fairer picture. (shrink)

Though complex networks have been widely applied in the research of chemistry, there is hardly any introduction about the establishment of networks using chemical bonds. In this paper, we consider chemical elements as a system linked by chemical bonds and create the undirected chemical bond network by abstracting nodes from elements and undirected edges from bonds. Connectivity, heterogeneity, small world and disassortativity of this network show the macro structural rationality of this system. The degree and k-order neighbors of an element, (...) which represent the micro topology of this network, can be used to measure its chemical reactivity and detect how many kinds of compounds it can form. The similarity between two elements is measured by the Jaccard index and the VOS mapping technique, results of which are similar to well-known similarities between elements shown by the periodic table. The establishment and topological analysis of this network provide another way to understand and study elements and bonds, and more chemical properties of elements and bonds can be studied by complex networks. (shrink)

This article presents a personal answer to the question “What is chemistry?”, set out in terms of six propositions. These cover “pure” and “applied” chemistry, different levels of description, and the broader context of chemistry.

In this paper it is performed a historical account of the theoretical roots that grounded the following four key basic ideas of chemical equilibrium: ‘incomplete reaction’, ‘reversibility’, ‘equilibrium constant’ and ‘molecular dynamics’. These notions developed in nineteenth-century as a consequence of the evolution of the concept of chemical affinity. The discussion begins with the presentation of the earliest affinity table [‘Table des rapports’] published in 1718 by Geoffroy. Afterwards, it is examined Bergman’s compilation. The theory supporting this arrangement assumed that (...) chemical displacement reactions were complete and could not be reversed. It is analysed how Berthollet’s model showed the inadequacy of this view. His new conceptual considerations established that the amount of the substances involved in a reaction was an essential factor determining its direction, which accounted for the early concepts of incomplete reaction and reversibility. Guldberg and Waage specified the role of mass in chemical equilibrium reactions as they considered the concentrations of the chemicals involved, formulating the first chemical equilibrium mathematical equation that approximates what is called nowadays chemical equilibrium constant. Finally, it is presented how Pfaundler was the first to consider the kinetic theory in the interpretation of the macroscopic properties of equilibrium reactions. (shrink)

Traditionally the study of chemical elements has been limited to well-known concepts like the periodic properties and chemical families. However, current information shows a new and rich language that allows us to observe relations in the elements that are not limited to their positions in the table. These relations are evident when reactions are represented through networks, as in the case of similar reactivity of organic compounds sharing functional groups. For the past two decades, it has been argued that network (...) reactions may be considered the core of chemistry. This network, which constitutes the basic set of chemical knowledge, provides the basis for classification and delivers routes to obtain new and known substances. In order to provide an example, we constructed and analyzed a network of chemical elements from the formation of stoichiometric binary compounds, providing to the chemistry, a formal structure of extracting the chemical knowledge. Thus, we explored all possible presence of relationships among elements. Concepts like degree centrality and centralization, the relationships among metals, semimetal and nonmetal classes, blocks, and chemical families were analyzed. We observed that the network structure had a small core set of elements of high reactivity and also a peripheral set of elements of low reactivity. The classes, blocks and families show the following increasing order of reactivity: nonmetals > semimetals > metals; p > s > d > f; and families: boron, carbon, pnictogens, chalcogens, halogens, lanthanoids > other families. This example shows, from the network perspective, that the elements and their classifications exhibit properties such as the reactivity, order, and similarity. (shrink)

In some views in the history, philosophy and social studies of chemistry, Joseph Priestley is at least as well-known and cited for his objections to the new chemistry and his promotion of his own late version of the theory of phlogiston, as for his early series of discoveries about types of air for which he had become famous. These citations are generally not associated with any detailed indications about his late work from 1788 onwards and his late phlogistic theory, of (...) which there has not been a detailed study. This paper undertakes a detailed study of Priestley’s late work on water and related airs. He put forward a theory to support which his apparatus and initial substances would have needed to exclude impurities altogether. His theory did not take into account the solutions to the difficulties with the experiment which had been comprehensively understood and published by the phlogistian Cavendish several years previously, and with which the Lavoisians were in agreement. Priestley readily and fundamentally changed his interpretations of experiments in order to support the theory he currently favoured, and he was highly selective about replying about the criticisms of any opponent. This detailed analysis shows many divergences between his own practices and aspects of his objections to the new chemistry, which have implications for those stances in the secondary literature which do not question his objections. Accordingly, this study has implications concerning the nature of chemistry and other sciences, how they do progress and how they should progress. (shrink)

Mendeleev’s successful predictions were the fruit of his insight into the structure of the periodic system. His failures were the result of pursuing the pattern he had perceived beyond the limits of its applicability. These two things are not equivalent.