This article compares treatments of the Stern–Gerlach experiment across different physical theories, building up to a novel analysis of electron spin measurement in the context of classical Dirac field theory. Modeling the electron as a classical rigid body or point particle, we can explain why the entire electron is always found at just one location on the detector but we cannot explain why there are only two locations where the electron is ever found. Using non-relativistic or relativistic quantum mechanics, we (...) can explain both uniqueness and discreteness. Moving to more fundamental physics, both features can be explained within a quantum theory of the Dirac field. In a classical theory of the Dirac field, the rotating charge of the electron can split into two pieces that each hit the detector at a different location. In this classical context, we can explain a feature of electron spin that is often described as distinctively quantum but we cannot explain another feature that could be explained within any of the other theories. (shrink)

In earlier work I wrestled with the question of the “ontological status” of organisms. It proved difficult to come to a clear decision, because there are many candidates for what such a status is or would be and of course many definitions of what organisms are. But what happens when we turn to theoretical projects “about” organisms that fall under the heading “organicist”? I first suggest that organicist projects have a problem: a combination of invoking Kant, or at least a (...) Kantian “regulative ideal,” usually presented as the epistemological component (or alternately, the complete overall vision) of a vision of organism – as instantiating natural purposes, as a type of “wholeWhole, wholes” distinct from a merely mechanistically specifiable set of parts, etc. – and a more ontological statement about the inherent or essential features of organisms, typically presented according to a combination of a “list of heroes” or “laundry list” of properties of organisms. This amounts to a category mistake. Other problems concern the too-strict oppositions between mechanism and organi(ci)sm, and symmetrical tendencies to “ontologize” (thus objectifying) properties of organisms and to “subjectify” them (turning them into philosophies of subjectivity). I don’t mean to suggest that no one should be an organicist or that Kant is a name that should be banished from civilized society. Rather, to borrow awkwardly from Sade, “organicists, one more effort!” if one wants a naturalistic, non-foundationalist concept of organicism, which is indeed quite active in recent theoretical biology, and which arguably was already alive in the organismic and even vitalist theories of thinkers like Goldstein and Canguilhem. (shrink)

Within quantum chemistry, the electron clouds that surround nuclei in atoms and molecules are sometimes treated as clouds of probability and sometimes as clouds of charge. These two roles, tracing back to Schrödinger and Born, are in tension with one another but are not incompatible. Schrödinger’s idea that the nucleus of an atom is surrounded by a spread-out electron charge density is supported by a variety of evidence from quantum chemistry, including two methods that are used to determine atomic and (...) molecular structure: the Hartree-Fock method and density functional theory. Taking this evidence as a clue to the foundations of quantum physics, Schrödinger’s electron charge density can be incorporated into many different interpretations of quantum mechanics. (shrink)

"A beautiful piece of work on the theory of altered states of consciousness ." "Stanislav Grof, M.D. author of Realms of the Human Unconsciousness".

Whenever I speak on the topic of dreams, I mention a very unusual of dream the lucid dream in which the dreamer knows he is dreaming and feels fully conscious difficulties in defining states of consciousness, I always ask weather anyone has the slightest doubt that he is awake that is in a normal state of consciouness at the moment; I have never found anyone who had difficulty in making this destinction.

Problems of self-interaction arise in both classical and quantum field theories. To understand how such problems are to be addressed in a quantum theory of the Dirac and electromagnetic fields (quantum electrodynamics), we can start by analyzing a classical theory of these fields. In such a classical field theory, the electron has a spread-out distribution of charge that avoids some of the problems of self-interaction facing point charge models. However, there remains the problem that the electron will experience self-repulsion. This (...) self-repulsion cannot be eliminated within classical field theory without also losing Coulomb interactions between distinct particles. But, electron self-repulsion can be eliminated from quantum electrodynamics in the Coulomb gauge by fully normal-ordering the Coulomb term in the Hamiltonian. After normal-ordering, the Coulomb term contains pieces describing attraction and repulsion between distinct particles and also pieces describing particle creation and annihilation, but no pieces describing self-repulsion. (shrink)

This volume focuses on the development of empiricism as an interest in the body - as both the object of research and the subject of experience.

Vitalism, from its early modern to its Enlightenment forms (from Glisson and Willis to La Caze and Barthez), is notoriously opposed to intervention into the living sphere. Experiment, quantification, measurement are all ‘vivisectionist’, morally suspect and worse, they alter and warp the ‘life’ of the subject. They are good for studying corpses, not living individuals. This much is well known, and it has disqualified vitalist medicine from having a place in standard histories of medicine, until recent, post-Foucauldian maneuvers have sought (...) to change the situation (but for unrelated, contextualist reasons). What is perhaps more suprising is that if we consider the emergence of medical ‘theory’ as a whole, from Harvey through to Locke and Sydenham, is the presence of a sustained anti-experimentalist line of argument, and this from the ‘empiricist’ (not Cartesian or Boerhaavian rationalist) side. It would seem then that ‘empiricks’, medical empiricists and other protagonists of an ‘embodied empiricism’ are not Boylean experimentalists who seek to map out Nature in its transparency, but deliberately archaic, Hippocratic observers of living bodies. (shrink)

There is debate as to whether quantum field theory is, at bottom, a quantum theory of fields or particles. One can take a field approach to the theory, using wave functionals over field configurations, or a particle approach, using wave functions over particle configurations. This article argues for a field approach, presenting three advantages over a particle approach: particle wave functions are not available for photons, a classical field model of the electron gives a superior account of both spin and (...) self-interaction as compared to a classical particle model, and the space of field wave functionals appears to be larger than the space of particle wave functions. The article also describes two important tasks facing proponents of a field approach: legitimize or excise the use of Grassmann numbers for fermionic field values and in wave functional amplitudes, and describe how quantum fields give rise to particle-like behavior. (shrink)

ABSTRACTMaterialism is the view that everything that is real is material or is the product of material processes. It tends to take either a ‘cosmological’ form, as a claim about the ultimate nature of the world, or a more specific ‘psychological’ form, detailing how mental processes are brain processes. I focus on the second, psychological or cerebral form of materialism. In the mid-to-late eighteenth century, the French materialist philosopher Denis Diderot was one of the first to notice that any self-respecting (...) materialist had to address the question of the status and functional role of the brain, and its relation to our mental life. After this the topic grew stale, with knee-jerk reiterations of ‘psychophysical identity’ in the nineteenth-century, and equally rigid assertions of anti-materialism. In 1960s philosophy of mind, brain–mind materialism reemerged as ‘identity theory’, focusing on the identity between mental processes and cerebral processes. In contrast, Diderot’s cerebral materialism allows for a more culturally sedimented sense of the brain, which he described in his late Elements of Physiology as a ‘book – except it is a book which reads itself’. Diderot thus provides a lesson for materialism as it reflects on the status of the brain, science and culture. (shrink)

reflection on misreadings of Adam Smith as vitalist in light of E Schliesser's Adam Smith book which shows a different interpretive route.

long version of review forthcoming in much shorter version in Classical Review.

Empiricism is a claim about the contents of the mind: its classic slogan is nihil est in intellectu quod non fuerit in sensu, ‘there is nothing in the mind (intellect, understanding) which is not first in the senses’. As such, it is not a claim about the fundamental nature of the world as material. I focus here on in an instance of what one might term the materialist appropriation of empiricism. One major component in the transition from a purely epistemological (...) claim about the mind and its contents, to an ontological claim about the nature of the world, is the new focus on brain-mind relations in the eighteenth century. Here I examine a Lockean trajectory as exemplified in Joseph Priestley’s 1777 Disquisitions Relating to Matter and Spirit. But Locke explicitly ruled out that his inquiry into the logic of ideas amounted to a ‘physical consideration of the mind’. What does it mean, then, for Priestley to present himself as continuing a Lockean tradition, while presenting mental processes as tightly identified with ‘an organical structure such as that of the brain’ (although he was not making a strict identity claim as we might understand it, post-Smart and Armstrong)? One issue here is that of Priestley's source of ‘empirical data’ regarding the correlation and indeed identification of mental and cerebral processes. David Hartley’s theory in his 1749 Observations on Man was, as is well known, republished in abridged form by Priestley, but he discards Hartley's 'vibratory neurophysiology' while retaining the associationist framework, although not because he disagreed with the former. Yet Hartley was at the very least, strongly agnostic about metaphysical issues (and it is difficult to study these authors while bracketing off religious considerations). One could see Locke and Hartley as articulating programs for the study of the mind which were more or less naturalistic (more strongly so in Hartley’s case) while avoiding ‘materialism’ per se; in contrast, Priestley bit the (materialist) bullet. In this paper I examine Priestley’s appropriation and reconstruction of this ‘micro-tradition’, while emphasizing its problems. (shrink)

Recent scholarship has focused attention on the difficulties that evil, suffering, and tragic conflict present to religious belief and moral life. Thinkers have drawn upon many important historical figures, with one significant exception - Augustine. At the same time, there has been a renaissance of work on Augustine, but little discussion of either his work on evil or his influence on contemporary thought. This book fills these gaps. It explores the 'family biography' of the Augustinian tradition by looking at Augustine's (...) work and its development in the writings of Hannah Arendt and Reinhold Niebuhr. Mathewes argues that the Augustinian tradition offers us a powerful, though commonly misconstrued, proposal for understanding and responding to evil's challenges. The book casts new light on Augustine, Niebuhr, and Arendt, as well as on the problem of evil, the nature of tradition, and the role of theological and ethical discourse in contemporary thought. (shrink)

Well prior to the invention of the term ‘biology’ in the early 1800s by Lamarck and Treviranus (and lesser-known figures in the decades prior), and also prior to the appearance of terms such as ‘organism’ under the pen of Leibniz and Stahl in the early 1700s, the question of ‘Life’, that is, the status of living organisms within the broader physico-mechanical universe, agitated different corners of the European intellectual scene. From modern Epicureanism to medical Newtonianism, from Stahlian animism to the (...) discourse on the ‘animal economy’ in vitalist medicine, models of living being were constructed in opposition to ‘merely anatomical’, structural, mechanical models. It is therefore striking that the classic narratives of the Scientific Revolution conspicuously avoid any consideration of what status to grant living beings in a newly physicalized universe (I discuss this in Wolfe 2011, 2019 chapt. 1). Neither Harvey, nor Boyle, nor Locke (to name some likely candidates, the latter having studied with Willis and collaborated with Sydenham) ever ask what makes organisms unique, or conversely, what does not. In this chapter I seek to establish how something we might call ‘the knowledge of Life’, to use an expression of Georges Canguilhem’s, emerged as part of early modernity without being part of the mainstream history of life science. This leads to the question, can one can correlate early modern “knowledge of life” with the emergence of a science called ‘biology’? (see Zammito 2018, Wolfe 2019, Bognon-Küss and Wolfe eds. 2019). It was once fashionable to speak of, e.g. ‘precursors of Darwin’, and then Canguilhem and Foucault famously did away with the category of precursor. But how then do we account for the phase that precedes the constitution of a science? With the case of biology, how do we account for the increasing fascination with the ontology of Life during the decades prior to the ‘naming of biology’, as McLaughlin has called it, at the end of the eighteenth century? This increased focus on Life and the ontology of Life sits awkwardly, both with mainstream narratives of the Scientific Revolution and of the history of biology. In seeking to address this increased focus (in which vitalism plays a role but was by no means the only conceptual actor: Wolfe 2020), I critically examine Foucault’s notorious claim (Foucault 1966) that there was no such thing as ‘Life’ in the eighteenth century and thus no such thing as biology. (shrink)

The brain in its plasticity and inherent 'sociality' can be proclaimed and projected as a revolutionary organ. Far from the old reactions which opposed the authenticity of political theory and praxis to the dangerous naturalism of 'cognitive science' (with images of men in white coats, the RAND Corporation or military LSD experiments), recent decades have shown us some of the potentiality of the social brain (Vygotsky, and more recently Negri 1995 and Negri 2000, Virno 2001). Is the brain somehow inherently (...) a utopian topos? If in some earlier papers I sought to defend naturalism against these reactions, here I consider a new challenge: the recently emerged disciplines of neuronormativity, which seek in their own way to overcome the nature-normativity divide. This is the task of a materialist brain theory today. 1. The setup: horns of a dilemma There is a lingering zone of what one might think of as sore cognitive muscle tissue in the area of materialism. It is an area of both contested territory and in some cases, a kind of pathos of distance of the 'Ugh! Keep that thing away from me!' sort. I have in mind the combination of materialism as an emancipatory socio-political project (which need not be construed in strictly Marx-Engels terms, if we think of Lucretius et al.) and as a cold-hearted 'spontaneous philosophy of the men in white coats', e.g. nefarious neurophilosophers. Faced with this rather massive alternative, this choice between two projects, I have stubbornly been saying since some discussions with Negri in the late 90s. (shrink)

A longstanding issue in attempts to understand the Everett (Many-Worlds) approach to quantum mechanics is the origin of the Born rule: why is the probability given by the square of the amplitude? Following Vaidman, we note that observers are in a position of self-locating uncertainty during the period between the branches of the wave function splitting via decoherence and the observer registering the outcome of the measurement. In this period it is tempting to regard each branch as equiprobable, but we (...) argue that the temptation should be resisted. Applying lessons from this analysis, we demonstrate (using methods similar to those of Zurek's envariance-based derivation) that the Born rule is the uniquely rational way of apportioning credence in Everettian quantum mechanics. In doing so, we rely on a single key principle: changes purely to the environment do not affect the probabilities one ought to assign to measurement outcomes in a local subsystem. We arrive at a method for assigning probabilities in cases that involve both classical and quantum self-locating uncertainty. This method provides unique answers to quantum Sleeping Beauty problems, as well as a well-defined procedure for calculating probabilities in quantum cosmological multiverses with multiple similar observers. (shrink)

What is theHistorical epistemologyhistorical epistemologyGayon, JeanOn historical epistemology of the life sciences? In what way does it differ from historico-philosophical reflection on “foundational” or “conceptual” issues in the sciences tout court? This is a question to which Jean Gayon and his mentor Georges CanguilhemCanguilhem, Georges devoted a considerable amount of effort, yielding somewhat different answers, as I will try to show. One obvious difference, as P.-O. MéthotMéthot, Pierre-Olivier has shown, is Gayon’s appropriation of anglophone philosophy of biology; another is Canguilhem'sCanguilhem, (...) Georges way of presenting his work as restricted to contextualized, historicist claims while in fact it is shot through with strong normative (and at times metaphysical) claims on Life, normativity, and value. In this essay I reflect on how to conduct historical epistemologiesHistorical epistemology of the life sciences, focusing on two interrelated cases I have worked on in the past: vitalismVitalism (history of) and the constitution of biology. (shrink)

The living body appears like an endlessly renewable reservoir of authenticity, hope, and taboo. But, for the sake of conceptual clarity, we are often been told that the (mere) body should be distinguished from the flesh. That is, it’s undeniable that I have a body; that I notice yours; that we worry about their birth and death and upkeep. But the flesh is a more transcendentalized, loaded concept – not least given its frequently religious background (incarnation: the Word made Flesh). (...) It is the body ‘kicked upstairs’, ‘bumped up’ one ontological level. Flesh is like a mantra, an obsessive leitmotif. Is the difference just one of abstraction? Indeed, crucial to the narrative of phenomenology (most obviously in Merleau-Ponty but really, throughout, including in enactivism), to the story of ancestor worship and identity it tells itself and its acolytes around the campfire, is a basic distinction between the merely physical body and the flesh as something requiring ‘mineness’, namely, an understanding of it as uniquely ‘my own’, a feeling of ‘what it is like to be embodied’. This goes back to the Husserlian distinction between Körper, ‘body’ in the sense of one body among others in a vast mechanistic universe of bodies, and Leib, ‘flesh’ in the sense of a subjectivity which is the locus of experience. In this essay I reflect on this vision of the body’s authenticity and its costs, and contrast it with insights derived from Georges Canguilhem, whose critique of mechanism/mechanicism is not done in the name of a wholescale organicism and/or an unproblematized éloge of embodiment and privacy. (shrink)

In his Système de la nature ou Essai sur les corps organisés, Pierre-Louis Moreau de Maupertuis, President of the Berlin Academy of Sciences and a natural philosopher with a strong interest in the modes of transmission of 'genetic' information, described living minima which he termed molecules, “endowed with desire, memory and intelligence.” Now, Maupertuis was a Leibnizian of sorts; his molecules possessed higher-level, 'mental' properties, recalling La Mettrie's statement in L'Homme-Machine, that Leibnizians have “rather spiritualized matter than materialized the soul.” (...) But Maupertuis also debated this issue with Diderot, who critiqued this theory in the additions to his 1753 Pensées sur l'interprétation de la nature. Where Maupertuis attributes higher-level properties to his living minima, Diderot argues that these can only be 'organizational', i.e., properties of the whole. At issue here is the degree of commitment to a form of materialism. (shrink)

Top-down models typically used to explain social behavior involve specific adaptations and higher level cognition. The Pavlovian conditioning model proposed can be extended to explain formation of dominance hierarchies and group structure, can replace a pheromonal model of reproductive suppression, and can be applied to language learning. This bottom-up approach based on general learning principles is a refreshing alternative to top-down models.

Our aim in this paper is to bring to light the importance of the notion of économie animale in Montpellier vitalism, as a hybrid concept which brings together the structural and functional dimensions of the living body – dimensions which hitherto had primarily been studied according to a mechanistic model, or were discussed within the framework of Stahlian animism. The celebrated image of the bee-swarm expresses this structural-functional understanding of living bodies quite well: “One sees them press against each other, (...) mutually supporting each other, forming a kind of whole, in which each living part, in its own way, by means of the correspondence and directions of its motions, enables this kind of life to be sustained in the body” (Encyclopédie, article “Observation,” by Ménuret de Chambaud). What is important here is that every component part is always a living part, i.e., every structural unit is always functional. Interestingly, while the twin notions of ‘animal economy’ and organisation are presented as improvements over a mechanistic perspective, they are nonetheless compatible with an expanded sense of mechanism and by extension, with materialism as reflected notably in the writings of Ménuret and Bordeu. We thus propose both a revision and reconstruction of the historical status of the ‘animal economy’, and a reflection on its conceptual status. (shrink)

This book provides an overview of key features of (philosophical) materialism, in historical perspective. It is, thus, a study in the history and philosophy of materialism, with a particular focus on the early modern and Enlightenment periods, leading into the 19th and 20th centuries. For it was in the 18th century that the word was first used by a philosopher (La Mettrie) to refer to himself. Prior to that, 'materialism' was a pejorative term, used for wicked thinkers, as a near-synonym (...) to 'atheist', 'Spinozist' or the delightful 'Hobbist'. The book provides the different forms of materialism, particularly distinguished into claims about the material nature of the world and about the material nature of the mind, and then focus on materialist approaches to body and embodiment, selfhood, ethics, laws of nature, reductionism and determinism, and overall, its relationship to science. For materialism is often understood as a kind of philosophical facilitator of the sciences, and the author want to suggest that is not always the case. Materialism takes on different forms and guises in different historical, ideological and scientific contexts as well, and the author wants to do justice to that diversity. Figures discussed include Lucretius, Hobbes, Gassendi, Spinoza, Toland, Collins, La Mettrie, Diderot, d'Holbach and Priestley; Büchner, Bergson, J.J.C. Smart and D.M. Armstrong. (shrink)

Here I explore a novel no-collapse interpretation of quantum mechanics that combines aspects of two familiar and well-developed alternatives, Bohmian mechanics and the many-worlds interpretation. Despite reproducing the empirical predictions of quantum mechanics, the theory looks surprisingly classical. All there is at the fundamental level are particles interacting via Newtonian forces. There is no wave function. However, there are many worlds.

David Hunt has recently developed a new strategy, called the “dispositional omniscience scenario,” or (OOS), which is designed to defeat theological fatalism by showing the compatibility of divine foreknowledge and human (libertarian) free agency. But I argue that Hunt fails to establish his compatibility claim because (DOS) is based on a defective analysis of dispositional belief that is too weak to sustain any divine foreknowledge of future free actions.