Abstract‘Structure’ is the term whose proper use is exemplified by an expression like ‘the structure of a diesel-engine,’ in which what is referred to is accessible to immediate observation. It is also used figuratively like ‘social structure.’ While unobservable, what is referred to is empirically accessible. By contrast, molecules are neither observable nor empirically accessible. What philosophical grounds enable us to design invisible structure of molecules? Our cognition of objects becomes realized as phenomena when objects are given to our phenomenal (...) fields. (Ochiai, Found Chem 22:77–86, 2020a, Found Chem 22:457–465, 2020b, A philosophical essay on molecular structure, Cambridge Scholars Publishing, Newcastle upon Tyne, pp 147–174, 2021) A phenomenal field is a pictorial representation of the mind’s self-transcending character and shows the relation between ‘self’ and ‘world.’ Molecular structure becomes realized as an affordance of molecules in a phenomenal field proper to organic chemists. It is a context-sensitive dispositional attribute of an {organic chemist-world} complex. Although designing molecules presupposes molecular structure, the latter is not sufficient for the former to make sense. Molecules must be designable as well. Designing molecules aims to create or modify molecular structure in order to provide compounds with certain chemical and/or physical properties. That is, designable molecules make sense in contexts in which they serve as a means to achieve this purpose and become realized as an affordance. Given that molecular structure and designable molecules are affordances of molecules, the fact that there are contexts in which they make sense provides grounds for conceiving and designing invisible structure of molecules. Heidegger’s arguments in Being and Time about characteristics of the being of beings corroborate our argument that what becomes realized as an affordance exists as what he calls a useful thing for us. (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)

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)

How do chemists assign numbers to chemicals properties? What do these numbers refer to? To answer these questions, we will first point out both the context-dependence of chemicals and the epistemic limitations of chemistry. We will then investigate how chemists use various procedures to stabilize measurements and how they use mixtures of samples as “references” in order to determine the amount of different chemicals in a sample. This study will enable us to query how it is possible for chemists to (...) change one factor while holding others constant at each step of the measurement procedure. This part of our work which will lead us to query the meaning of the ceteris paribus clause and the very possibility of making holistic inferences in the domain of chemistry. To conclude, we will highlight how methodological pluralism developed by chemists makes it possible for a relational type of consistency to emerge. (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)