Philosophy of immunology is a subfield of philosophy of biology dealing with ontological and epistemological issues related to the studies of the immune system. While speculative investigations and abstract analyses have always been part of immune theorizing, until recently philosophers have largely ignored immunology. Yet the implications for understanding the philosophical basis of organismal functions framed by immunity offer new perspectives on fundamental questions of biology and medicine. Developed in the context of history of medicine, theoretical biology, and medical anthropology, (...) philosophy of immunology differs from these related branches of study in its focus on traditional philosophical questions concerning identity, individuality, ecology, cognition, scientific methodology and theory construction. This broad agenda derives from immunology’s multifaceted research program that has developed from its initial clinical challenges of host defense, transplantation, autoimmunity, tumor immunology, and allergy. In addition to these well-established research areas, immunity is now understood to play a central role in other physiological functions, development, ecology, and evolutionary mechanics. Holding together these diverse domains of inquiry lie philosophical commitments oriented by organismal identity. In this regard, pertinent issues are raised concerning cognition (organization of immune perception and information processing), the character of individuality (framed by the ecological context of immune-mediated assimilation and rejection), and the dynamics of complex systems (understood as holistic systems biology). Indeed, immunology, in the context of cognitive science, evolutionary biology, environmental sciences, and development provides multi-focal perspectives for philosophy of science. (shrink)

The emerging field of synthetic biology aims to engineer novel biological entities. The envisioned future bio-based economy builds largely on “cell factories”: organisms that have been metabolically engineered to sustainably produce substances for human ends. In this paper, we argue that synthetic biology’s goal of creating efficient production vessels for industrial applications implies a set of ontological assumptions according to which living organisms are machines. Traditionally, a machine is understood as a technological, isolated and controllable production unit consisting of parts. (...) But modified organisms, or hybrids, require us to think beyond the machine paradigm and its associated dichotomies between artificial and natural, organisms and artefacts. We ask: How may we conceptualise hybrids beyond limiting ontological categories? Our main claim is that the hybrids created by synthetic biology should be considered not as machines but as metabolic systems. We shall show how the philosophical account of metabolism can inform an ontology of hybrids that moves beyond what we call the “machine ontology”, considering that metabolism enables thinking beyond the dominant dichotomies and allows us to understand and design lifeforms in a bio-based economy. Thus, the aim of this paper is twofold: first, to develop the philosophical ontology of hybrids, and second, to move synthetic biology beyond the problematically limiting view of hybrids. (shrink)

“The Role of the Individual in Evolution” is a prescient yet neglected 1941 work by the 20th century’s most important paleontologist, George Gaylord Simpson. In a curious intermingling of explanation and critique, Simpson engages questions that would become increasingly fundamental in modern biological theory and philosophy. Did individuality, adaptation, and evolutionary causation reside at more than one level: the cell, the organism, the genetically coherent reproductive group, the social group, or some combination thereof? What was an individual, anyway? In this (...) introduction, we highlight two points in a wider historical context. First, recognizing the political context of Simpson’s writing profoundly deepens our understanding of the development of his science as the Modern Evolutionary Synthesis infused biology. Second, this story illuminates the emergence of debates around what would eventually come to be called multilevel selection theory. The organism-centered concept of biological individuality defended by Simpson is situated in relation to the then-emerging Synthesis, in which he was a renowned player, and also in relation to the views he opposed: the “metaphysical” ideas of paleontologists such as Henry Fairfield Osborn, who claimed that some evolutionary trends derived from potentialities already implanted in the germplasm; and the organicist ideas of Ralph W. Gerard and the Chicago School of ecologists, which he derided as all too congenial to totalitarianism. We find parallels between the ways that Simpson thought then about human individuality under totalitarianism and the way he thought about individuality in evolution; not that any causal relationship linked the two, but that commonalities of hierarchical structure exist between single entities and groups in both instances. We then trace the subsequent development of Simpson’s political and philosophical takes on the role of the individual in evolution through the 1960s and lightly sketch out the later fate of the organicist ideas of the Chicago School. Simpson’s paper, originally published in the Journal of the Washington Academy of Sciences, is available as supplementary material in the online version of this article, as part of the "Classics in Biological Theory" collection. (shrink)

This essay considers how scholarly approaches to the development of molecular biology have too often narrowed the historical aperture to genes, overlooking the ways in which other objects and processes contributed to the molecularization of life. From structural and dynamic studies of biomolecules to cellular membranes and organelles to metabolism and nutrition, new work by historians, philosophers, and STS scholars of the life sciences has revitalized older issues, such as the relationship of life to matter, or of physicochemical inquiries to (...) biology. This scholarship points to a novel molecular vista that opens up a pluralist view of molecularizations in the twentieth century and considers their relevance to current science. (shrink)

In this paper we address the issue of how to think about immunity. Many immunological writings suggest a straightforward option: the view that the immune system is primarily a system of defense, which naturally invites the talk of strong immunity and strong immune response. Despite their undisputable positive role in immunology, such metaphors can also pose a risk of establishing a narrow perspective, omitting from consideration phenomena that do not neatly fit those powerful metaphors. Building on this analysis, we argue (...) two things. First, we argue that the immune system is involved not only in defense. Second, by disentangling various possible meanings of ‘strength’ and ‘weakness’ in immunology, we also argue that such a construal of immunity generally contributes to the distortion of the overall picture of what the immune system is, what it does, and why it sometimes fails. Instead, we propose to understand the nature of the immune system in terms of contextuality, regulation, and trade-offs. We suggest that our approach provides lessons for a general understanding of the organizing principles of the immune system in health and disease. For all this to work, we discuss a wide range of immunological phenomena. (shrink)

Since the early nineteenth century a membrane or wall has been central to the cell’s identity as the elementary unit of life. Yet the literally and metaphorically marginal status of the cell membrane made it the site of clashes over the definition of life and the proper way to study it. In this article I show how the modern cell membrane was conceived of by analogy to the first “artificial cell,” invented in 1864 by the chemist Moritz Traube (1826–1894), and (...) reimagined by the plant physiologist Wilhelm Pfeffer (1845–1920) as a precision osmometer. Pfeffer’s artificial cell osmometer became the conceptual and empirical basis for the law of dilute solutions in physical chemistry, but his use of an artificial analogue to theorize the existence of the plasma membrane as distinct from the cell wall prompted debate over whether biology ought to be more closely unified with the physical sciences, or whether it must remain independent as the science of life. By examining how the histories of plant physiology and physical chemistry intertwined through the artificial cell, I argue that modern biology relocated vitality from protoplasmic living matter to nonliving chemical substances—or, in broader cultural terms, that the disenchantment of life was accompanied by the (re)enchantment of ordinary matter. (shrink)

In 1926, Haldane published an essay titled 'On Being the Right Size' in which he argued that the structure, function, and behavior of an organism are strongly conditioned by the physical forces that exert the greatest impact at the scale at which it exists. This chapter puts Haldane’s insight to work in the context of contemporary cell and molecular biology. Owing to their minuscule size, cells and molecules are subject to very different forces than macroscopic organisms. In a sense, macroscopic (...) and microscopic entities inhabit different “worlds”: the former is ruled by gravity and inertia, whereas the latter is governed by Brownian motion. One implication is that we should be extremely skeptical of models and analogies that seek to explain properties of microscopic entities by appealing to properties of macroscopic ones. Unfortunately, this is precisely what the appeal to engineering metaphors in molecular biology attempts to do. Molecular biologists routinely resort to such metaphors because they are familiar and intuitively intelligible. But if our machines were the size of molecules it would be impossible for them to function the way they do. It follows that we should avoid distorting biological reality by construing it in engineering terms. In this chapter I examine four key metaphors in molecular biology – “genetic program,” “cellular circuitry,” “molecular machine,” and “molecular motor” – and I argue that their deficiencies derive from their neglect of scale. I also try to explain why many biologists today appear to have forgotten the importance of scale that Haldane drew attention to in his essay. I suggest that the reason has to do with the influence of Schrödinger’s argument in 'What is Life?' regarding the stability of the gene. (shrink)

Metaphors play a crucial role in the understanding of science. Since antiquity, metaphors have been used in technical texts to describe structures unknown or unnamed; besides establishing a terminology of science, metaphors are also important for the expression of concepts. However, a concise terminology to classify metaphors in the language of science has not been established yet. But in the context of studying the history of a science and its concepts, a precise typology of metaphors can be helpful. Metaphors have (...) a lot in common with models in science, as has been observed already. In this paper, therefore, I suggest a typology of metaphor in ancient science to fill this terminological gap by using concepts applied to the classification of models in science, as coined by Rom Harré. I propose to differentiate between homeoconceptual metaphors and paraconceptual metaphors. Furthermore, functional and structural aspects of metaphors in ancient science are taken into account. Case studies from ancient texts displaying metaphors in ancient science are presented and classified following the outlined typology of metaphors. (shrink)

From the mid-nineteenth century to the Gilded Age, Catharine Beecher and other American social reformers combined natural theology and evangelism to instruct their audiences how to lead healthy, virtuous, and happy lives. Worried about the consequences of urbanization, industrialization, unstable sexual and gender roles, and immigration, these “Christian physiologists” provided prescriptive scientific advice for hygiene and personal conduct based on the traditional norms of white, middle-class, Protestant domesticity. According to Beecher and her counterparts, the biosocial reproduction of ideal American households (...) promised to reverse the degeneration of men and women across the country and to ensure the long-term vitality of their children. Using evidence from Beecher, Harriet Beecher Stowe, Charlotte Perkins Gilman, and other nineteenth-century writers, I investigate the methods and aims of Christian physiology along with its relationships to natural theology, Darwinian feminism, and other reform movements. I also analyze how Beecher and her successors employed concepts including the machine, the tissue, the cell, and the germ to justify their conclusions about the optimal structure and functions of American society. Overall, I demonstrate how these actors leveraged the body and the family as mechanisms to produce healthy parents, children, and communities for an ailing nation. (shrink)

There is a deep-seated neopositivist view which regards the language of science as a neutral medium of communication, radically different from indirect symbolic forms of discourse characteristic of arts and humanities. But naturalists, like poets and social scientists, also draw on the dominant images in their culture to organize their thoughts and simplify complex concepts. By conceptualizing one thing in terms of another, metaphors in science not only aid mutual communication between researchers but also structure their understanding of experience and (...) reality. Too transparent to be noticed and critically analyzed within the framework of science itself, metaphors act as lenses, making selected aspects of complex phenomena visible to study and investigation (Reynolds 2018). By linking two seemingly unrelated ideas, for example, those of a machine and DNA replication, metaphors establish new interactions of meaning evoking shared associated connotations between these interacting concepts (Black 1962). This, in turn, may not only transform the perception of a target domain but also open up new prospects for experimental and interpretative avenues. Understanding Metaphors by Andrew Reynolds draws on this vision of metaphors as indispensable tools of scientific thinking to elucidate their role in the life sciences. (shrink)