Mathias Frisch

Models not only represent but may also influence their targets in important ways. While models’ abilities to influence outcomes has been studied in the context of economic models, often under the label ‘performativity’, we argue that this phenomenon also pertains to epidemiological models, such as those used for forecasting the trajectory of the Covid-19 pandemic. After identifying three ways in which a model by the Covid-19 Response Team at Imperial College London may have influenced scientific advice, policy, and individual responses, we consider the implications of epidemiological models’ performative capacities. We argue, first, that performativity may impair models’ ability to successfully predict the course of an epidemic; but second, that it may provide an additional sense in which these models can be successful, namely by changing the course of an epidemic.

How could the initial, drastic decisions to implement “lockdowns” to control the spread of COVID-19 infections be justifiable, when they were made on the basis of such uncertain evidence? We defend the imposition of lockdowns in some countries by first, and focusing on the UK, looking at the evidence that undergirded the decision, second, arguing that this provided us with sufficient grounds to restrict liberty given the circumstances, and third, defending the use of poorly-empirically-constrained epidemiological models as tools that can legitimately guide public policy.

When do probability distribution functions (PDFs) about future climate misrepresent uncertainty? How can we recognise when such misrepresentation occurs and thus avoid it in reasoning about or communicating our uncertainty? And when we should not use a PDF, what should we do instead? In this paper we address these three questions. We start by providing a classification of types of uncertainty and using this classification to illustrate when PDFs misrepresent our uncertainty in a way that may adversely affect decisions. We then discuss when it is reasonable and appropriate to use a PDF to reason about or communicate uncertainty about climate. We consider two perspectives on this issue. On one, which we argue is preferable, available theory and evidence in climate science basically excludes using PDFs to represent our uncertainty. On the other, PDFs can legitimately be provided when resting on appropriate expert judgement and recognition of associated risks. Once we have specified the border between appropriate and inappropriate uses of PDFs, we explore alternatives to their use. We briefly describe two formal alternatives, namely imprecise probabilities and possibilistic distribution functions, as well as informal possibilistic alternatives. We suggest that the possibilistic alternatives are preferable.

In an illuminating article, Claus Beisbart argues that the recently-popular thesis that the probabilities of statistical mechanics (SM) are Best System chances runs into a serious obstacle: there is no one axiomatization of SM that is robustly best, as judged by the theoretical virtues of simplicity, strength, and fit. Beisbart takes this 'no clear winner' result to imply that the probabilities yielded by the competing axiomatizations simply fail to count as Best System chances. In this reply, we express sympathy for the 'no clear winner' thesis. However, we argue that an importantly different moral should be drawn from this. We contend that the implication for Humean chances is not that there are no SM chances, but rather that SM chances fail to be sharp

In recent work on the foundations of statistical mechanics and the arrow of time, Barry Loewer and David Albert have developed a view that defends both a best system account of laws and a physicalist fundamentalism. I argue that there is a tension between their account of laws, which emphasizes the pragmatic element in assessing the relative strength of different deductive systems, and their reductivism or funda- mentalism. If we take the pragmatic dimension in their account seriously, then the laws of the special sciences should be part of our best explanatory system of the world, as well.

This paper provides a survey of several philosophical issues arising in classical electrodynamics arguing that there is a philosophically rich set of problems in theories of classical physics that have not yet received the attention by philosophers that they deserve. One issue, which is connected to the philosophy of causation, concerns the temporal asymmetry exhibited by radiation fields in the presence of wave sources. Physicists and philosophers disagree on whether this asymmetry reflects a fundamental causal asymmetry or is due to statistical or thermodynamic considerations. I suggest that an explanation appealing to the asymmetry of causation is more promising. Another issue concerns the conceptual structure of the theory. Despite its empirical success, classical electrodynamics faces serious foundational problems. Models of charged particles involve what by the theory's own lights are idealizations, I maintain, and this is a feature that is not readily captured by traditional philosophical accounts of scientific theories. Other issues I discuss concern (i) the relation between Lorentz's theory of the electron and Einstein's Theory of Special Relativity; (ii) the notion of the domain of a theory, the question of theory reduction, and the relation between classical and more fundamental quantum theories; and (iii) the role of locality constraints, their relation to the concept of causation; and the status of locality conditions in the semi-classical theory of the Aharanov-Bohm effect.

I examine Harvey Brown’s account of relativity as dynamic and constructive theory and Michel Janssen recent criticism of it. By contrasting Einstein’s principle-constructive distinction with a related distinction by Lorentz, I argue that Einstein's distinction presents a false dichotomy. Appealing to Lorentz’s distinction, I argue that there is less of a disagreement between Brown and Janssen than appears initially and, hence, that Brown’s view presents less of a departure from orthodoxy than it may seem. Neither the kinematics-dynamics distinction nor Einstein’s principle- and constructive theory distinction ultimately capture their disagreement, which may instead be a disagreement about the role of modality in science and the explanatory force of putatively nomic constraints.

According to a view widely held among philosophers of science, the notion of cause has no legitimate role to play in mature theories of physics. In this paper I investigate the role of what physicists themselves identify as causal principles in the derivation of dispersion relations. I argue that this case study constitutes a counterexample to the popular view and that causal principles can function as genuine factual constraints. 1. Introduction2. Causality and Dispersion Relations3. Norton's Skepticism4. Conclusion.

Much has been written on the role of causal notions and causal reasoning in the so-called 'special sciences' and in common sense. But does causal reasoning also play a role in physics? Mathias Frisch argues that, contrary to what influential philosophical arguments purport to show, the answer is yes. Time-asymmetric causal structures are as integral a part of the representational toolkit of physics as a theory's dynamical equations. Frisch develops his argument partly through a critique of anti-causal arguments and partly through a detailed examination of actual examples of causal notions in physics, including causal principles invoked in linear response theory and in representations of radiation phenomena. Offering a new perspective on the nature of scientific theories and causal reasoning, this book will be of interest to professional philosophers, graduate students, and anyone interested in the role of causal thinking in science.

According to a widespread view, which can be traced back to Russell’s famous attack on the notion of cause, causal notions have no legitimate role to play in how mature physical theories represent the world. In this paper I first critically examine a number of arguments for this view that center on the asymmetry of the causal relation and argue that none of them succeed. I then argue that embedding the dynamical models of a theory into richer causal structures can allow us to decide between models in cases where our observational data severely underdetermine our choice of dynamical models

Many contemporary philosophers of physics (and philosophers of science more generally) follow Bertrand Russell in arguing that there is no room for causal notions in physics. Causation, as James Woodward has put it, has a ‘human face’, which makes causal notions sit ill with fundamental theories of physics. In this paper I examine a range of anti-causal arguments and show that the human face of causation is the face of scientific representations much more generally. Physics, like other sciences, is deeply permeated with causal reasoning

Climate change presents us with a problem of intergenerational justice. While any costs associated with climate change mitigation measures will have to be borne by the world’s present generation, the main beneficiaries of mitigation measures will be future generations. This raises the question to what extent present generations have a responsibility to shoulder these costs. One influential approach for addressing this question is to appeal to neo-classical economic cost–benefit analyses and so-called economy-climate “integrated assessment models” to determine what course of action a principle of intergenerational welfare maximization would require of us. I critically examine a range of problems for this approach. First, integrated assessment models face a problem of underdetermination and induction: They are very sensitive to a number of highly conjectural assumptions about economic responses to a temperature and climate regime, for which we have no empirical evidence. Second, they involve several simplifying assumptions which cannot be justified empirically. And third, some of the assumptions underlying the construction of economic models are intrinsically normative assumptions that reflect value judgments of the modeler. I conclude that, while integrated assessment models may play a useful role as “toy models,” their use as tools for policy optimization is highly problematic

Classical dispersion relations are derived from a time-asymmetric constraint. I argue that the standard causal interpretation of this constraint plays a scientifically legitimate role in dispersion theory, and hence provides a counterexample to the causal skepticism advanced by John Norton and others. Norton ([2009]) argues that the causal interpretation of the time-asymmetric constraint is an empty honorific and that the constraint can be motivated by purely non-causal considerations. In this paper I respond to Norton's criticisms and argue that Norton's skepticism derives its force partly by holding causal principles to a standard too high to be met by other scientifically legitimate constraints

In order to motivate the thesis that there is no single concept of causation that can do justice to all of our core intuitions concerning that concept, Ned Hall has argued that there is a conflict between a counterfactual criterion of causation and the condition of causal locality. In this paper I critically examine Hall's argument within the context of a more general discussion of the role of locality constraints in a causal conception of the world. I present two strategies that defenders of counterfactual accounts of causation can pursue to respond to Hall's challenge—including the adoption of a counterfactual condition that is sufficient for causal action-at-a-distance in place of Hall's ‘process’ condition—and conclude that Hall's argument against counterfactual accounts of causation is unsuccessful.

Many climate scientists have made claims that may suggest that evidence used in tuning or calibrating a climate model cannot be used to evaluate the model. By contrast, the philosophers Katie Steele and Charlotte Werndl have argued that, at least within the context of Bayesian confirmation theory, tuning is simply an instance of hypothesis testing. In this paper I argue for a weak predictivism and in support of a nuanced reading of climate scientists’ concerns about tuning: there are cases, model-tuning among them, in which predictive successes are more highly confirmatory of a model than accommodation of evidence

I discuss two case studies from classical electrodynamics challenging the distinction between laws that delineate physically possible words and initial conditions. First, for many reasonable initial conditions there exist no global solutions to the Maxwell‐Lorentz equations for continuous charge distributions. Second, in deriving an equation of motion for a charged point particle one needs to invoke an asymptotic condition that seems to express a physically contingent fact even though it is mathematically necessary for the derivation.

In Frisch 2004 and 2005 I showed that the standard ways of modeling particle-field interactions in classical electrodynamics, which exclude the interactions of a particle with its own field, results in a formal inconsistency, and I argued that attempts to include the self-field lead to numerous conceptual problems. In this paper I respond to criticism of my account in Belot 2007 and Muller 2007. I concede that this inconsistency in itself is less telling than I suggested earlier but argue that existing solutions to the theory's foundational problems do not support the kind of traditional philosophical conception of scientific theorizing defended by Muller and Belot. *Received January 2007; revised October 2007. †To contact the author, please write to: Department of Philosophy, University of Maryland, Skinner Building, College Park, MD 20742; e-mail: [email protected].

Mathias Frisch provides the first sustained philosophical discussion of conceptual problems in classical particle-field theories. Part of the book focuses on the problem of a satisfactory equation of motion for charged particles interacting with electromagnetic fields. As Frisch shows, the standard equation of motion results in a mathematically inconsistent theory, yet there is no fully consistent and conceptually unproblematic alternative theory. Frisch describes in detail how the search for a fundamental equation of motion is partly driven by pragmatic considerations (like simplicity and mathematical tractability) that can override the aim for full consistency. The book also offers a comprehensive review and criticism of both the physical and philosophical literature on the temporal asymmetry exhibited by electromagnetic radiation fields, including Einstein's discussion of the asymmetry and Wheeler and Feynman's influential absorber theory of radiation. Frisch argues that attempts to derive the asymmetry from thermodynamic or cosmological considerations fail and proposes that we should understand the asymmetry as due to a fundamental causal constraint. The book's overarching philosophical thesis is that standard philosophical accounts that strictly identify scientific theories with a mathematical formalism and a mapping function specifying the theory's ontology are inadequate, since they permit neither inconsistent yet genuinely successful theories nor thick causal notions to be part of fundamental physics.