The general question to be considered in this paper points to the nature of the world described by chemistry: what is macro-chemical ontology like? In particular, we want to identify the ontological categories that underlie chemical discourse and chemical practice. This is not an easy task, because modern Western metaphysics was strongly modeled by theoretical physics. For this reason, we attempt to answer our question by contrasting macro-chemical ontology with the mainstream ontology of physics and of traditional metaphysics. In particular, (...) we introduce the distinction between stuff-ontology, proper of chemistry, and individual-ontology, proper of physics. These two ontologies differ from each other in the basic categories of their own structures. On this basis, we characterize individual-ontology in such a way that the features of stuff-ontology will arise by contrast with it. (shrink)

resumo: Este artigo pretende mostrar que sem a influência de uma filosofia construtivista que eu denomino boa, representada principalmente por Bruno Latour, a elucidação das substâncias químicas teria sido virtualmente impossível. Sem a noção de materiais “artefatuais” cunhada por eles, a Química Moderna seria impensável a partir dos metaparadigmas em uso no campo atual da história e da filosofia da ciência. A tese central que defendo aqui é a de que o construtivismo, tal como definido pelos antropológos da ciência, é (...) uma maneira disfarçada de colocar a histórica filosofia materialista na trilha da discussão histórica e filosófica das ciências e tecnologias e que isso restaura o papel desempenhado pelos materiais usados pelos cientistas para que sejam exatamente o que são. abstract: This paper aims to show that without the influence of a constructivist philosophy I call good, mainly represented by Bruno Latour, the ontological elucidation of the chemical substances would have been virtually impossible. Without the notion of artifactual materials given by them, would be Modern Chemistry unthinkable from the metaparadigms in use in the present field of history and philosophy of science. The central thesis I defended here is that constructivism as defined by the anthropologists of science is a disguised way of sliding historical materialist philosophy into the mainline of philosophical and historical discussion of the sciences and technologies and that those restore the role played by the materials used by sciences to be exactly what they are. (shrink)

In the context of 1960s research on biological membranes, scientists stumbled upon a curiously coloured material substance, which became called the “purple membrane.” Interactions with the material as well as chemical analyses led to the conclusion that the microbial membrane contained a photoactive molecule similar to rhodopsin, the light receptor of animals’ retinae. Until 1975, the find led to the formation of novel objects in science, and subsequently to the development of a field in the molecular life sciences that comprised (...) biophysics, bioenergetics as well as membrane and structural biology. Furthermore, the purple membrane and bacteriorhodopsin, as the photoactive membrane transport protein was baptized, inspired attempts at hybrid bio-optical engineering throughout the 1980s. A central motif of the research field was the identification of a functional biological structure, such as a membrane, with a reactive material substance that could be easily prepared and manipulated. Building on this premise, early purple membrane research will be taken as a case in point to understand the appearance and transformation of objects in science through work with material substances. Here, the role played by a perceptible material and its spontaneous change of colour, or reactivity, casts a different light on objects and experimental practices in the late twentieth century molecular life sciences. With respect to the impact of chemical working and thinking, the purple membrane and rhodopsins represent an influential domain straddling the life and chemical sciences as well as bio- and material technologies, which has received only little historical and philosophical attention. Re-drawing the boundary between the living and the non-enlivened, these researches explain and model organismic activity through the reactivity of macromolecular structures, and thus palpable material substances. (shrink)

In this paper we will argue that the categories of physical individuals and chemical stuff are not sufficient to face the chemical ontology if nanomaterials are taken into account. From a perspective that considers ontological questions and wonders which the items involved in science are, we will argue that the domain of nanoscience must be considered as populated by entities that are neither individuals, as those of physics, nor stuff, as those items of macro-chemistry. This discussion, in virtue of the (...) analysis of the nature of nanomaterials, leads to propose a proper ontological category for nanoparticles: nanoindividuals. Nanomaterials are sorts of individuals, but they are different from physical individuals and from chemical stuff. We will also claim to contribute to the growing field of the philosophy of chemistry, especially regarding discussions that manifest not only epistemological but also ontological issues. In this scenario, the field on nanoscience is particularly challenging. (shrink)