Publications

Note: For a full list of publications, work under review, presentations, etc., see my CV.

Monograph

Abductive Reasoning in Science

Cambridge University Press (Elements in Philosophy of Science). Penultimate draft of the table of contents and introduction.

Abstract: In abductive reasoning, scientific theories are evaluated on the basis of how well they would explain the available evidence. There are a number of subtly different accounts of this type of reasoning, most of which are inspired by the popular slogan ‘Inference to the Best Explanation’. However, these accounts disagree about exactly how to spell out the slogan so as to avoid various problems for abductive reasoning. This Element aims, firstly, to give an opinionated overview both of the many accounts of abductive reasoning that have been proposed and the problems that have motivated them; and, secondly, to critically evaluate these accounts in a way that points towards a systematic view of the nature and purpose of abductive reasoning in science.

Peer-Reviewed Articles (in English)

Most of my papers are written in English and intended for an international audience. However, I have also written a few research articles in Icelandic; please scroll down for details on these.

What Is Philosophical Progress? (with Tina Firing, Insa Lawler and James Norton)

Forthcoming in Philosophy and Phenomenological Research. Penultimate draft.

Abstract: What is it for philosophy to make progress? While various putative forms of philosophical progress have been explored in some depth, this overarching question is rarely addressed explicitly, perhaps because it has been assumed to be intractable or unlikely to have a single, unified answer. In this paper, we aim to show that the question is tractable, that it does admit of a single, unified answer, and that one such answer is plausible. This answer is, roughly, that philosophical progress consists in putting people in a position to increase their understanding, where 'increased understanding' is a matter of better representing the network of dependence relations between phenomena. After identifying four desiderata for an account of philosophical progress, we argue that our account meets the desiderata in a particularly satisfying way. Among other things, the account explains how various other achievements, such as philosophical arguments, counterexamples, and distinctions, may contribute to progress. Finally, we consider the implications of our account for the pressing and contentious question of how much progress has been made in philosophy.

Probabilifying Reflective Equilibrium

In Synthese. Penultimate draft.

Abstract: This paper aims to flesh out the celebrated notion of reflective equilibrium within a probabilistic framework for epistemic rationality. On the account developed here, an agent's attitudes are in reflective equilibrium when there is a certain sort of harmony between the agent's credences, on the one hand, and what the agent accepts, on the other hand. Somewhat more precisely, reflective equilibrium is taken to consist in the agent accepting, or being prepared to accept, all and only claims that follow from a maximally comprehensive theory that is more probable than any other such theory. Drawing on previous work, the paper shows that when an agent is in reflective equilibrium in this sense, the set of claims they accept or are prepared to accept is bound to be logically consistent and closed under logical implication. The paper also argues that this account can explain various features of philosophical argumentation in which the notion of reflective equilibrium features centrally, such as the emphasis on evaluating philosophical theories holistically rather than in a piecemeal fashion.

Interthematic Polarization

In American Philosophical Quarterly. Penultimate draft.

Abstract: In recent epistemology, belief polarization is generally defined as a process by which a disagreement on a single proposition becomes more extreme over time. Outside of the philosophical literature, however, ‘polarization’ is often used for a different epistemic phenomenon, namely the process by which people’s beliefs on unrelated topics become increasingly correlated over time. This paper argues that the latter type of polarization, here labeled interthematic polarization, is often rational from each individual’s point of view. This suggests that belief polarization is not necessarily a failure of individual rationality, but instead a failure of the social structures within which we live our epistemic lives.

Excessive Testimony: When Less Is More

In Philosophy and Phenomenological Research. Penultimate draft, link to article (open access).

Abstract: This paper identifies two distinct dimensions of what might be called testimonial strength: first, in the case of testimony from more than one speaker, testimony can be said to be stronger to the extent that a greater proportion of the speakers give identical testimony; second, in both single-speaker and multi-speaker testimony, testimony can be said to the stronger to the extent that each speaker expresses greater conviction in the relevant proposition. These two notions of testimonial strength have received scant attention in the philosophical literature so far, presumably because it has been thought that whatever lessons we learn from thinking about testimony as a binary phenomenon will apply mutatis mutandis to varying strengths of testimony. This paper shows that this will not work for either of the two aforementioned dimensions of testimonial strength, roughly because less testimony can provide more justification in a way that can only be explained by appealing to the (non-binary) strength of the testimony itself. The paper also argues that this result undermines some influential versions of non-reductionism about testimonial justification.

Disagreement and Consensus in Science

Forthcoming in Maria Baghramian, J. Adam Carter & Richard Rowland (eds.), Routledge Handbook of Disagreement. Penultimate draft.

Abstract: Consensus and disagreement play important roles in the practice, development, and dissemination of science. This raises a host of important philosophical questions. Some of these issues are conceptual: When, exactly, does a scientific agreement count as a consensus? And in what sense, if any, is disagreement the opposite of consensus? Other questions concern the role of consensus and disagreement in the development of science: For example, is consensus on central methodological issues and assumptions necessary for scientific work to proceed normally? Yet other questions are epistemological: From a layperson’s perspective, does the presence of a scientific consensus ever indicate that the relevant theory is probably correct? If so, what are the conditions under which it does so? Relatedly, should scientists themselves also defer to the consensus position among their peers whenever such a consensus exists? Or should they instead evaluate consensus theories for themselves, or even actively aim to dissent against such theories?

Would Disagreement Undermine Progress? (with Insa Lawler and James Norton)

In The Journal of Philosophy. Penultimate draft.

Abstract: In recent years, several philosophers have argued that their discipline makes no progress (or not enough in comparison to the ‘hard sciences’). A key argument for this pessimistic position appeals to the purported fact that philosophers widely and systematically disagree on most major philosophical issues. In this paper, we take a step back from the debate about progress in philosophy specifically and consider the general question: How (if at all) would disagreement within a discipline undermine that discipline's progress? We reconstruct two distinct arguments from disagreement to a lack of progress, and argue that each rests on underscrutinized assumptions about the nature of progress. We then provide independent motivation to reject those assumptions. The upshot of these considerations is that widespread expert disagreement within a discipline is compatible with progress in that discipline. Indeed, progress can occur even as such disagreement increases. However, disagreement can undermine our ability to tell which developments are progressive (and to what degree). We conclude that while disagreement can indeed be a threat to progress (in philosophy and elsewhere), the precise nature of the threat has not been appreciated.

The Noetic Approach: Scientific Progress as Enabling Understanding

In Y. Shan (ed.), New Philosophical Perspectives on Scientific Progress (Routledge, 2022). Penultimate draft.

Abstract: Roughly, the noetic account characterizes scientific progress in terms of increased understanding. This chapter outlines a version of the noetic account according to which scientiﬁc progress on some phenomenon consists in making scientiﬁc information publicly available so as to enable relevant members of society to increase their understanding of that phenomenon. This version of the noetic account is briefly compared with four rival accounts of scientific progress, viz. the truthlikeness account, the problem-solving account, the new functional account, and the epistemic account. In addition, the chapter seeks to precisify the question that accounts of scientific progress are (or should be) aiming to answer, viz. “What type of cognitive change with respect to a given topic or phenomenon X constitutes a (greater or lesser degree of) scientific improvement with respect to X?”

Scientific Progress without Justification

In K. Khalifa, I. Lawler, and E. Shech, Scientific (eds.), Scientific Understanding and Representation: Modeling in the Physical Sciences (Routledge, 2022). Penultimate draft.

Abstract: According to some prominent accounts of scientific progress, e.g. Bird’s epistemic account, accepting new theories is progressive only if the theories are justified in the sense required for knowledge. This paper argues that epistemic justification requirements of this sort should be rejected because they misclassify many paradigmatic instances of scientific progress as non-progressive. In particular, scientific progress would be implausibly rare in cases where (a) scientists are aware that most or all previous theories in some domain have turned out to be false, or (b) the new theory was a result of subsuming and/or logically strengthening previous theories, or (c) scientists are aware of significant peer disagreement about which theory is correct.

Scientific Progress without Problems: A Reply to McCoy

In K. Khalifa, I. Lawler, and E. Shech, Scientific (eds.), Scientific Understanding and Representation: Modeling in the Physical Sciences (Routledge, 2022). Penultimate draft.

Abstract: In the course of developing an account of scientific progress, C. D. McCoy (2022) appeals centrally to understanding as well as to problem-solving. On the face of it, McCoy’s account could thus be described as a kind of hybrid of the understanding-based account that I favor (Dellsén 2016, 2021) and the functional (a.k.a. problem-solving) account developed most prominently by Laudan (1977; see also Kuhn 1970; Shan 2019). In this commentary, I offer two possible interpretations of McCoy’s account and explain why I do not find it entirely compelling on either interpretation.

Consensus versus Unanimity: Which Carries More Weight?

Forthcoming in The British Journal for the Philosophy of Science. Penultimate draft.

Abstract: Around 97% of climate scientists endorse anthropogenic global warming (AGW), the theory that human activities are partly responsible for recent increases in global average temperatures. Clearly, this widespread endorsement of AGW is a reason for non-experts to believe in AGW. But what is the epistemic significance of the fact that some climate scientists do not endorse AGW? This paper contrasts expert unanimity, in which virtually no expert disagrees with some theory, with expert consensus, in which some non-negligible proportion either rejects or is uncertain about the theory. It is argued that, from a layperson’s point of view, an expert consensus is often stronger evidence for a theory’s truth than unanimity. Several lessons are drawn from this conclusion, e.g. concerning what laypeople should infer from expert pronouncements, how journalists should report on scientific theories, and how working scientists should communicate with the public.

An Epistemic Advantage of Accommodation over Prediction

Forthcoming in Philosophers' Imprint. Penultimate draft, link to article (open access).

Abstract: Many philosophers have argued that a hypothesis is better confirmed by some data if the hypothesis was not specifically designed to fit the data. ‘Prediction’, they argue, is superior to ‘accommodation’. Others deny that there is any epistemic advantage to prediction, and conclude that prediction and accommodation are epistemically on a par. This paper argues that there is a respect in which accommodation is superior to prediction. Specifically, the information that the data was accommodated rather than predicted suggests that the data is less likely to have been manipulated or fabricated, which in turn increases the likelihood that the hypothesis is correct in light of the data. In some cases, this epistemic advantage of accommodation may even outweigh whatever epistemic advantage there might be to prediction, making accommodation epistemically superior to prediction all things considered.

Scientific Progress: By-Whom or For-Whom?

In Studies in History and Philosophy of Science. Penultimate draft, link to article (open access).

Abstract: When science makes cognitive progress, who or what is it that improves in the requisite way? According to a widespread and unchallenged assumption, it is the cognitive attitudes of scientists themselves, i.e. the agents by whom scientific progress is made, that improve during progressive episodes. This paper argues against this assumption and explores a different approach. Scientific progress should be defined in terms of potential improvements to the cognitive attitudes of those for whom progress is made, i.e. the receivers rather than the producers of scientific information. This includes not only scientists themselves, but also various other individuals who utilize scientific information in different ways for the benefit of society as a whole.

Understanding Scientific Progress: The Noetic Account

In Synthese. Link to article (open access).

Abstract: What is scientific progress? This paper advances an interpretation of this question, and an account that serves to answer it (thus interpreted). Roughly, the question is here understood to concern what type of cognitive change with respect to a topic or phenomenon X constitutes a scientific improvement (to a greater or lesser extent) with respect to X. The answer explored in the paper is that the requisite type of cognitive change occurs when scientific results are made publicly available so as to make it possible for anyone to increase their understanding of X. This account is briefly compared to two rival accounts of scientific progress, based respectively on increasing truthlikeness and accumulating knowledge, and is argued to be preferable to both.

Thinking about Progress: From Science to Philosophy (with Insa Lawler and James Norton)

In Noûs. Link to article (open access).

Abstract: Is there progress in philosophy? If so, how much? Philosophers have recently argued for a wide range of answers to these questions, from the view that there is no progress whatsoever to the view that philosophy has provided answers to all the big philosophical questions. However, these views are diﬃcult to compare and evaluate, because they rest on very diﬀerent assumptions about the conditions under which philosophy would make progress. This paper looks to the comparatively mature debate about scientiﬁc progress for inspiration on how to formulate four distinct accounts of philosophical progress, in terms of truthlikeness, problem-solving, knowledge, and understanding. Equally importantly, the paper outlines a common framework for how to understand and evaluate these accounts. We distill a series of lessons from this exercise, to help pave the way for a more fruitful discussion about philosophical progress in the future.

Explanatory Consolidation: From ‘Best’ to ‘Good Enough’

In Philosophy and Phenomenological Research. Penultimate draft, link to article.

Abstract: In science and everyday life, we often infer that something is true because it would explain some set of facts better than any other hypothesis we can think of. But what if we have reason to believe that there is a better way to explain these facts that we just haven’t thought of? Wouldn’t that undermine our warrant for believing the best available explanation? Many philosophers have assumed that we can solve such underconsideration problems by stipulating that a hypothesis should not only be ‘the best’ explanation available; rather, it should also be ‘good enough’. Unfortunately, however, the only current suggestion for what it might mean to say that an explanation is ‘good enough’ is, well, not good enough. This paper aims to provide a better account of what is required for an explanatory hypothesis to be considered ‘good enough’. In brief, the account holds that a ‘good enough’ hypothesis is one that has gone through a process that I call explanatory consolidation, in which accumulating evidence and failed attempts to formulate better alternatives gradually make it more plausible that the explanation we currently have is better than any other that could be formulated.

We Owe It to Others to Think for Ourselves

In J. Matheson and K. Lougheed (eds.), Epistemic Autonomy (Routledge). Penultimate draft.

Abstract: We are often urged to figure things out for ourselves rather than to rely on other people’s say-so, and thus be ‘epistemically autonomous’ in one sense of the term. But why? For almost any important question, there will be someone around you who is at least as well placed to answer it correctly. So why bother making up your own mind at all? I consider, and then reject, two ‘egoistic’ answers to this question according to which thinking for oneself is beneficial for the autonomous agent herself. I go on to suggest that the reason we should (sometimes) think for ourselves is that doing so (sometimes) increases the collective reliability of the epistemic community to which we belong. In many cases, this will do nothing at all to increase our own chances of forming correct beliefs. So, at least in this respect, the rationale for being epistemically autonomous is entirely ‘altruistic’.

Expanding the Empirical Realm: Constructive Empiricism and Augmented Observation

Forthcoming in C. Beisbart and M. Frauchiger (eds.), Scientific Theories and Philosophical Stances: Themes from van Fraassen (De Gruyter). Penultimate draft.

Abstract: Manifestationalism holds that science aims only to give us theories that are correct about what has been observed thus far. Several philosophers, including Bas van Fraassen, have argued that manifestationalism cannot make sense of the scientific impetus to make new observations, since such observations only risk turning manifestationally adequate theories into inadequate ones. This paper argues that a strikingly similar objection applies to van Fraassen’s own constructive empiricism, the view that science aims only to find theories that are empirically adequate. Roughly, the objection is that constructive empiricism cannot make sense of the scientific impetus to expand the limits of what can be observed, since such expansions only risk turning empirically adequate theories into inadequate ones.

The Epistemic Impact of Theorizing: Generation Bias Implies Evaluation Bias

In Philosophical Studies. Penultimate draft, link to article.

Abstract: It is often argued that while biases routinely influence the generation of scientific theories (in the ‘context of discovery’), a subsequent rational evaluation of such theories (in the ‘context of justification’) will ensure that biases do not affect which theories are ultimately accepted. Against this line of thought, this paper shows that the existence of certain kinds of biases at the generation-stage implies the existence of biases at the evaluation-stage. The key argumentative move is to recognize that a scientist who comes up with a new theory about some phenomena has thereby gained an unusual type of evidence, viz. information about the space of theories that could be true of the phenomena. It follows that if there is bias in the generation of scientific theories in a given domain, then the rational evaluation of theories with reference to the total evidence in that domain will also be biased.

Scientific Realism in the Wild: An Empirical Study of Seven Sciences and HPS (with James Beebe)

In Philosophy of Science. Penultimate draft, link to article.

Abstract: We report the results of a study that investigated the views of researchers working in seven scientific disciplines (physics, chemistry, biology, economics, psychology, sociology, and anthropology) and in HPS (N = 1,798) in regard to four hypothesized dimensions of scientific realism. Among other things, we found (i) that natural scientists tended to express more strongly realist views than social scientists, (ii) that social scientists working in fields where quantitative methods predominate tended to express more strongly realist views than social scientists working in fields where qualitative methods are more common, (iii) that HPS scholars tended to express more anti-realist views than natural scientists, aligning themselves with social scientists working in fields where qualitative methods are more common, (iv) that van Fraassen’s characterization of scientific realism failed to cluster with more standard characterizations, (v) that a van Fraassen-style anti-realism is significantly more popular among scientists and HPS scholars than more standard forms of anti-realism, and (vi) that while those who endorsed the No-Miracles Argument were more likely to endorse scientific realism, those who endorsed the Pessimistic Induction were no more or less likely to endorse anti-realism.

Rational Understanding: Toward a Probabilistic Epistemology of Acceptability

In Synthese (special issue entitled "Themes from Elgin"). Penultimate draft, link to article.

Abstract: To understand something involves some sort of commitment to a set of propositions comprising an account of the understood phenomenon. Some take this commitment to be a species of belief; others, such as Elgin and I, take it to be a kind of cognitive policy. This paper takes a step back from debates about the nature of understanding and asks when this commitment involved in understanding is epistemically appropriate, or `acceptable' in Elgin's terminology. In particular, appealing to lessons from the lottery and preface paradoxes, it is argued that this type of commitment is sometimes acceptable even when it would be rational to assign arbitrarily low probabilities to the relevant propositions. This strongly suggests that the relevant type of commitment is sometimes acceptable in the absence of epistemic justification for belief, which in turn implies that understanding does not require justification in the traditional sense. The paper goes on to develop a new probabilistic model of acceptability, based on the idea that the maximally informative accounts of the understood phenomenon should be optimally probable. Interestingly, this probabilistic model ends up being similar in important ways to Elgin’s proposal to analyze the acceptability of such commitments in terms of ‘reflective equilibrium’.

Should Scientific Realists Embrace Theoretical Conservatism?

In Studies in History and Philosophy of Science (special issue on scientific novelty). Penultimate draft, link to article.

Abstract: A prominent type of scientific realism holds that some important parts of our best current scientific theories are at least approximately true. According to such realists, radically distinct alternatives to these theories or theory-parts are unlikely to be approximately true. Thus one might be tempted to argue, as the prominent anti-realist Kyle Stanford recently did, that realists of this kind have little or no reason to encourage scientists to attempt to identify and develop theoretical alternatives that are radically distinct from currently accepted theories in the relevant respects. In other words, it may seem that realists should recommend that scientists be relatively conservative in their theoretical endeavors. This paper aims to show that this argument is mistaken. While realists should indeed be less optimistic of finding radically distinct alternatives to replace current theories, realists also have greater reasons to value the outcomes of such searches. Interestingly, this holds both for successful and failed attempts to identify and develop such alternatives.

The Epistemic Value of Expert Autonomy

In Philosophy and Phenomenological Research. Penultimate draft, link to article.

Abstract: According to an influential Enlightenment ideal, one shouldn't rely epistemically on other people's say-so, at least not if one is in a position to evaluate the relevant evidence for oneself. However, in much recent work in social epistemology, we are urged to dispense with this ideal, which is seen as stemming from a misguided focus on isolated individuals to the exclusion of groups and communities. In this paper, I argue that that an emphasis on the social nature of inquiry should not lead us to entirely abandon the Enlightenment ideal of epistemically autonomous agents. Specifically, I suggest that it is an appropriate ideal for those who serve as experts in a given epistemic community, and develop a notion of expert acceptance to make sense of this. I go on to show that, all other things being equal, this kind of epistemic autonomy among experts makes their joint testimony more reliable, which in turn brings epistemic benefits both to laypeople and to experts in other fields.

Divergent Perspectives on Expert Disagreement: Preliminary Evidence from Climate Science, Climate Policy, Astrophysics, and Public Opinion (with James Beebe, Maria Baghramian and Luke Drury)

In Environmental Communications. Link to article, penultimate draft.

Abstract: We report the results of an exploratory study that examines the judgments of climate scientists, climate policy experts, astrophysicists, and non-experts (N = 3367) about the factors that contribute to the creation and persistence of disagreement within climate science and astrophysics and about how one should respond to expert disagreement. We found that, as compared to non-experts, climate experts believe that within climate science (i) there is less disagreement about climate change, (ii) methodological factors play less of a role in generating disagreements, (iii) fewer personal or institutional biases influence climate research, and (iv) there is more agreement about which methods should be used to examine relevant phenomena we also observed that the uniquely American political context predicted experts’ judgments about some of these factors. We also found that, in regard to disagreements concerning cosmic ray physics, and commensurate with the greater inherent uncertainty and data lacunae in their field, astrophysicists working on cosmic rays were generally more willing to acknowledge expert disagreement, more open to the idea that a set of data can have multiple valid interpretations, and generally less quick to dismiss someone articulating a non-standard view as non-expert, than climate scientists were in regard to climate science.

Beyond Explanation: Understanding as Dependency Modeling

In The British Journal for the Philosophy of Science. Link to article, penultimate draft.

(Received an honorable mention for the 2020 Popper prize for the best paper published in the BJPS that year.)

Abstract: This paper presents and argues for an account of objectual understanding that aims to do justice to the full range of cases of scientific understanding, including cases in which one does not have an explanation of the understood phenomenon. According to the proposed account, one understands a phenomenon just in case one grasps a sufficiently accurate and comprehensive model of the ways in which it or its features are situated within a network of dependence relations; one’s degree of understanding is proportional to the comprehensiveness and accuracy of such a model. I compare this account with accounts of scientific understanding that explicate understanding in terms of having an explanation of the understood phenomenon. I discuss three distinct types of cases in which scientific understanding does not amount to possessing an explanation of any kind, and argue that the proposed model-based account can accommodate these cases while still retaining a strong link between understanding and explanation.

Scientific Progress: Four Accounts

In Philosophy Compass. Link to article, penultimate draft.

Abstract: Scientists are constantly making observations, carrying out experiments, and analyzing empirical data. Meanwhile, scientific theories are routinely being adopted, revised, discarded, and replaced. But when are such changes to the content of science improvements on what came before? This is the question of scientific progress. One answer is that progress occurs when scientific theories ‘get closer to the truth’, i.e. increase their degree of truthlikeness. A second answer is that progress consists in increasing theories’ effectiveness for solving scientific problems. A third answer is that progress occurs when the stock of scientific knowledge accumulates. A fourth and final answer is that scientific progress consists in increasing scientific understanding, i.e. the capacity to correctly explain and reliably predict relevant phenomena. This paper compares and contrasts these four accounts of scientific progress, considers some of the most prominent arguments for and against each account, and briefly explores connections to different forms of scientific realism.

Scientific Progress, Understanding, and Knowledge: Reply to Park

In Journal for General Philosophy of Science. Link to paper, penultimate draft.

(This is a response to Sungbae Park's Does Scientific Progress Consist in Increasing Knowledge or Understanding?, which in turn is a response to my Scientific Progress: Understanding versus Knowledge.)

Abstract: Dellsén (2017) has recently argued for an understanding-based account of scientific progress, the noetic account, according to which science (or a particular scientific discipline) makes cognitive progress precisely when it increases our understanding of some aspect of the world. Dellsén contrasts this account with Bird’s (2007, 2015) epistemic account, according to which such progress is made precisely when our knowledge of the world is increased or accumulated. In a recent paper, Park (2017) criticizes various aspects of Dellsén’s account and his arguments in favor of the noetic account as against Bird’s epistemic account. This paper responds to Park’s objections. Since a number of Park’s arguments rely on the idea that scientific progress may merely consists in “achieving the means to increase knowledge” (Park 2017: 570), I will start by discussing this “means-end thesis”.

Promotion as Contrastive Increase in Expected Fit (with Nathaniel Sharadin)

In Philosophical Studies. Link to article, penultimate draft.

Abstract: What is required for an action to promote the satisfaction of a desire? We reject extant answers and propose an an alternative. Our account differs from competing answers in two ways: first, it is contrastive , in that actions promote the satisfaction of desires only as contrasted with other possible actions. Second, it employs a notion of expected fit between desire and world, defined as the weighted sum of the fit between the desire and the world in all possible outcomes, where each weight is given by the probability of the agent’s obtaining the relevant outcome. According to our proposal, then, an action promotes a desire when the expected fit for the desire given that the agent performs the action is greater than the expected fit of the desire given that the agent performs the contrasting action. We highlight this account’s attractive features and explain how it improves on its competitors.

The Beliefs and Intentions of Buridan's Ass (with Nathaniel Sharadin)

In Journal of the American Philosophical Association. Link to article, penultimate draft.

Abstract: The moral of Buridan's Ass is that it can sometimes be rational to perform one action rather than another even though one lacks stronger reason to do so. Yet it is also commonly believed that it cannot ever be rational to believe one proposition rather than another if one lacks stronger reason to do so. This asymmetry has been taken to indicate a deep difference between epistemic and practical rationality. According to the view articulated here, the asymmetry should instead be explained by the difference between rational intentions and rational actions. Thus, it turns out, Buridan's Ass-style cases do not indicate an asymmetry between epistemic and practical rationality as such.

The Heuristic Conception of Inference to the Best Explanation

In Philosophical Studies. Link to article; penultimate draft.

Abstract: An influential suggestion about the relationship between Bayesianism and Inference to the Best Explanation (IBE) holds that IBE functions as a heuristic to approximate Bayesian reasoning. While this view promises to unify Bayesianism and IBE in a very attractive manner, important elements of the view have not yet been spelled out in detail. I present and argue for a heuristic conception of IBE on which IBE serves primarily to locate the most probable available explanatory hypothesis to serve as a working hypothesis in an agent's further investigations. Along the way, I criticize what I consider to be an overly ambitious conception of the heuristic role of IBE, according to which IBE serves as a guide to absolute probability values. My own conception, by contrast, requires only that IBE can function as a guide to the comparative probability values of available hypotheses. This is shown to be a much more realistic role for IBE given the nature and limitations of the explanatory considerations with which IBE operates.

Abductively Robust Inference

In Analysis. Link to article, penultimate draft.

Abstract: Inference to the Best Explanation (IBE) is widely criticized for being an unreliable form of ampliative inference – partly because the explanatory hypotheses we have considered at a given time may all be false, and partly because there is an asymmetry between the comparative judgment on which an IBE is based and the absolute verdict that IBE is meant to license. In this paper, I present a further reason to doubt the epistemic merits of IBE and argue that it motivates moving to an inferential pattern in which IBE emerges as a degenerate limiting case. Since this inferential pattern is structurally similar to an argumentative strategy known as Inferential Robustness Analysis (IRA), it effectively combines the most attractive features of IBE and IRA into a unified approach to non-deductive inference.

When Expert Disagreement Supports the Consensus

In Australasian Journal of Philosophy. Link to article, penultimate draft.

Abstract: It is often suggested that disagreement among scientific experts is a reason not to trust those experts, even about matters on which they are in agreement. In direct opposition to this view, I argue here that the very fact that there is disagreement among experts on a given issue provides a positive reason for non-experts to trust that the experts really are justified in their attitudes towards consensus theories. I show how this line of thought can be spelled out in three distinct frameworks for non-deductive reasoning, viz. Bayesian Confirmation Theory, Inference to the Best Explanation, and Inferential Robustness Analysis.

Deductive Cogency, Understanding, and Acceptance

In Synthese. Link to article, penultimate draft.

Abstract: Deductive Cogency holds that the set of propositions towards which one has, or is prepared to have, a given type of propositional attitude should be consistent and closed under logical consequence. While there are many propositional attitudes that are not subject to this requirement, e.g. hoping and imagining, it is at least prima facie plausible that Deductive Cogency applies to the doxastic attitude involved in propositional knowledge, viz. (outright) belief. However, this thought is undermined by the well-known preface paradox, leading a number of philosophers to conclude that Deductive Cogency has at best a very limited role to play in our epistemic lives. I argue here that Deductive Cogency is still an important epistemic requirement, albeit not as a requirement on belief. Instead, building on a distinction between belief and acceptance introduced by Jonathan Cohen and recent developments in the epistemology of understanding, I propose that Deductive Cogency applies to the attitude of treating propositions as given in the context of attempting to understand a given phenomenon. I then argue that this simultaneously accounts for the plausibility of the considerations in favor of Deductive Cogency and avoids the problematic consequences of the preface paradox.

Reactionary Responses to the Bad Lot Objection

In Studies in History and Philosophy of Science. Link to article, penultimate draft.

Abstract: As it is standardly conceived, Inference to the Best Explanation (IBE) is a form of ampliative inference in which one infers a hypothesis because it provides a better potential explanation of one’s evidence than any other available, competing explanatory hypothesis. Bas van Fraassen famously objected to IBE thus formulated that we may have no reason to think that any of the available, competing explanatory hypotheses are true. While revisionary responses to the Bad Lot Objection concede that IBE needs to be reformulated in light of this problem, reactionary responses argue that the Bad Lot Objection is fallacious, incoherent, or misguided. This paper shows that the most influential reactionary responses to the Bad Lot Objection do nothing to undermine the original objection. This strongly suggests that proponents of IBE should focus their efforts on revisionary responses, i.e. on finding a more sophisticated characterization of IBE for which the Bad Lot Objection loses its bite.

Realism and the Absence of Rivals

In Synthese. Link to article, penultimate draft.

Abstract: Among the most serious challenges to scientific realism are arguments for the underdetermination of theory by evidence. This paper defends a version of scientific realism against what is perhaps the most influential recent argument of this sort, viz. Kyle Stanford’s New Induction over the History of Science. An essential part of the defense consists in a probabilistic analysis of the slogan “absence of evidence is not evidence of absence”. On this basis it is argued that the likelihood of a theory being underdetermined depends crucially on social and historical factors, such as the structure of scientific communities and the time that has passed since the theory first became accepted. This is then shown to serve as the epistemological foundation for a version of scientific realism which avoids Stanford’s New Induction in a principled and non-question-begging way.

Understanding without Justification or Belief

In Ratio. Link to article, penultimate draft.

Abstract: In recent years there has been a resurgence of interest among epis- temologists in the nature of understanding, with some authors arguing that understanding should replace knowledge as the pri- mary focus of epistemology. But what is understanding? According to what is often called the standard view, understanding is a species of knowledge. Although this view has recently been challenged in various ways, even the critics of the standard view have assumed that understanding requires justification and belief. I argue that it requires neither. If sound, these arguments have important upshots not only for the nature of understanding, but also for its distinctive epistemic value and its role in contemporary epistemology.

Reconstructed Empiricism

In Acta Analytica. Link to article, penultimate draft.

Abstract: According to Bas van Fraassen, scientific realists and anti-realists disagree about whether accepting a scientific theory involves believing that the theory is true. On van Fraassen’s own anti-realist empiricist position, accepting a theory involves believing only that the theory is correct in its claims about observable aspects of the world. However, a number of philosophers have argued that acceptance and belief cannot be distinguished and thus that the debate is either confused or trivially settled in favor of the realist. In addition, another set of philosophers have argued that van Fraassen’s empiricist position appeals to an unmotivated distinction between observable and unobservable aspects of the world. This paper aims to reconstruct a van Fraassen-style empiricism about scientific acceptance that avoids these two objections – reconstructed empiricism.

Certainty and Explanation in Descartes' Philosophy of Science

In HOPOS: Journal of the International Society for History of Philosophy of Science. Link to article, penultimate draft.

Abstract: This paper presents a new approach to resolving an apparent tension in Descartes’ discussion of scientific theories and explanations in the Principles of Philosophy. On the one hand, Descartes repeatedly claims that any theories presented in science must be certain and indubitable. On the other hand, Descartes himself presents an astonishing number of speculative explanations of various scientific phenomena. In response to this tension, commentators have suggested that Descartes changed his mind about scientific theories having to be certain and indubitable, that he lacked the conceptual resources to describe the appropriate epistemic attitude towards speculative theories, or that the presence of geometrical principles in these explanations guarantee their certainty. I argue that none of these responses is satisfactory and suggest a different resolution to the tension by examining Descartes’ notion of explanation. On Descartes’ view, providing an adequate explanation does not require being certain of the theories that constitute the explanans. Relatedly, the purpose of Cartesian explanations is not to discover the truth about the various underlying mechanisms that such explanations appeal to, but to support his general philosophical thesis that all natural phenomena can be explained by appealing to the extension of matter.

Scientific Progress: Knowledge versus Understanding

In Studies in History and Philosophy of Science. Link to article, penultimate draft.

Abstract: What is scientific progress? On Alexander Bird’s epistemic account of scientific progress, an episode in science is progressive precisely when there is more scientific knowledge at the end of the episode than at the beginning. Using Bird’s epistemic account as a foil, this paper develops an alternative understanding- based account on which an episode in science is progressive precisely when scientists grasp how to correctly explain or predict more aspects of the world at the end of the episode than at the beginning. This account is shown to be superior to the epistemic account by examining cases in which knowledge and understanding come apart. In these cases, it is argued that scientific progress matches increases in scientific understanding rather than accumulations of knowledge. In addition, considerations having to do with minimalist idealizations, pragmatic virtues, and epistemic value all favor this understanding- based account over its epistemic counterpart.

There May Yet Be Non-Causal Explanations (of Particular Events)

In Journal for General Philosophy of Science. Link to article, penultimate draft.

Abstract: There are many putative counterexamples to the view that all scientific expla- nations are causal explanations. Using a new theory of what it is to be a causal explanation, Bradford Skow has recently argued that several of the putative counterexamples fail to be non-causal. This paper defends some of the counterexamples by showing how Skow’s argument relies on an overly permissive theory of causal explanations.

Explanatory Rivals and the Ultimate Argument

In Theoria. Link to article, penultimate draft.

Abstract: Although many aspects of Inference to the Best Explanation (IBE) have been extensively discussed, very little has so far been said about what it takes for a hypothesis to count as a rival explanatory hypothesis in the context of IBE. The primary aim of this article is to rectify this situation by arguing for a specific account of explanatory rivalry. On this account, explanatory rivals are (roughly speaking) complete explanations of a given explanandum. When explanatory rivals are conceived of in this way, I argue that IBE is a more plausible and defensible rule of inference than it would otherwise be. The secondary aim of the article is to demonstrate the importance of accounts of explanatory rivalry by examining a prominent philosophical argument in which IBE is employed, viz. the so-called Ultimate Argument for scientific realism. In short, I argue that a well-known objection to the Ultimate Argument due to Arthur Fine fails in virtue of tacitly assuming an account of explanatory rivalry that we have independent reasons to reject.

Peer-Reviewed Articles in Icelandic

The following is a list of (peer-reviewed) research articles published in Icelandic journals. I have included English abstract where available; otherwise I have included a short summary in English.

Fyrir hverja eru fræðin?

English title: "Who Is Science For?"

In Ritið. Icelandic text.

English abstract: It seems uncontroversial that scientific and academic research should aim to benefit not only those who carry out the research, but the public at large as well. Science is for all of us. On closer examination, however, this innocuous idea turns out to raise various philosophical questions, regarding inter alia the value of knowledge, the nature of scientific and academic research, and the division of labor within societies. In an effort to address these questions, I formulate a philosophical theory that I call epistemic egalitarianism, which roughly states that it is valuable for anyone to know certain things. I then defend this theory and use it to substantiate the idea that science is for all of us. Towards the end of the paper, I consider the practical consequences of accepting this idea for scientific and academic research: What would science be like if it were truly for all of us?

Gildi vísinda og gildin í vísindum -- á tímum heimsfaraldurs

English title: "The Value of Science and the Values in Science -- in Pandemic Times"

In Skírnir. Icelandic text.

English summary: This paper uses research on the COVID-19 pandemic as the backdrop for an accessible discussion of the value and status of science, and of the role of valuesin science. In particular, the paper seeks to debunk three common myths or dogmas about scientific research: (i) that there is such a thing as 'scientific proof' of a theory or hypothesis, (ii) that disagreement is necessarily unhealthy or unnatural in science, (iii) and that personal values play no role in scientific research.

Að treysta sérfræðingum: Hvar, hvenær og hvers vegna?

English title: "Trusting Experts: What, When, and Why?"

In Ritið. Penultimate draft.

English abstract: In order for experts to serve as authorities in our society, people need to trust them when they make claims that fall withing their domains of expertise. However, it also seems important for people to think independently and critically about the experts‘ conclusions – one shouldn‘t believe everything one is told. In this paper, I examine this tension with the aim of answering four closely related questions: (1) What is it to trust experts? (2) Why do we often have to rely on experts? (3) Which experts should we trust more than others, and in what circumstances? (4) And in what circumstances is it important to think critically and try to reach our own conclusions?

Frá skoðunum til trúnaðar og aftur til baka: Yfirlit um bayesíska þekkingarfræði

English title: "From Belief to Credence and Back Again: An Overview of Bayesian Epistemology"

In Hugur. Penultimate draft.

English abstract: This paper discusses the delicate relationship between traditional epistemology and the increasingly influential probabilistic (or ‘Bayesian’) approach to epistemology. The paper introduces some of the key ideas of probabilistic epistemology, including credences or degrees of belief, Bayes’ theorem, conditionalization, and the Dutch Book argument. The tension between traditional and probabilistic epistemology is brought out by considering the lottery and preface paradoxes as they relate to rational (binary) belief and credence respectively. It is then argued that this tension can be alleviated by rejecting the requirement that rational (binary) beliefs must be consistent and closed under logical entailment. Instead, it is suggested that this logical requirement applies to a different type of binary propositional attitude, viz. acceptance.

Hlutdrægni í vísindum: Vanákvörðun, tilleiðsluáhætta og tilurð kenninga

English title: "Biased Science: Underdetermination, Inductive Risk, and Discovery"

In Ritið. Icelandic text.

English abstract: Feminist philosophers of science have argued that various biases can and do influence the results of scientific investigations. Two kinds of arguments have been most influential: On the one hand, it has been argued that biased assumptions frequently bridge the gap between observation and theory associated with ‘the underdetermination thesis’. On the other hand, it has been argued that biased value judgments determine when the evidence in favor of a particular theory is considered sufficiently strong for the theory to be accepted as true. This paper argues that bias can influence the results of scientific investigations via a third route. Briefly, biases can and do influence which theories are seriously proposed and considered in scientific communities, which in turn leads to otherwise promising theories being ignored when scientists are choosing between such theories. In the final section, I suggest that this result speaks in favor of taking a quite radical approach to eliminating unwanted biases in science.

Gagnrýnin og vísindaleg hugsun

English title: "Scientific versus Critical Thinking"

In Skírnir. Icelandic text.

English summary: This paper engages with a tradition in Icelandic philosophy of theorizing about critical thinking. The central thesis of the paper is that critical thinking should not be identified with scientific thinking, since scientific research is often (and inevitably so) based on a kind of epistemic trust in other scientists' testimony that is incompatible with critical thinking. The paper also criticizes the idea that critical thinking should be associated with any of Charles Peirce's four ways of forming beliefs in "The Fixation of Belief".

Tvö viðhorf til vísindalegrar þekkingar – eða eitt?

English title: “Reconciling two Approaches to the Epistemology of Science”

In Ritið. Icelandic text.

English abstract: There are two main approaches to the epistemology of science. On the one hand, some hold that a scientific hypothesis is confirmed to the extent that the hypothesis explains the evidence better than alternative hypotheses concerning the same subject-matter. This idea is often referred to as Inference to the Best Explanation. On the other hand, some hold that a scientific hypothesis is confirmed to the extent that the hypothesis is probable given the evidence. This idea is often associated with Bayesianism or Bayesian epistemology. Opinions differ on whether and how these two approaches may be reconciled. This paper criticizes some recent attempts to make peace between Bayesianism and Inference to the Best Explanation and sketches a new account of how the two approaches may be reconciled.