We might think that thought experiments are at their most powerful or most interesting when they produce new knowledge. This would be a mistake; thought experiments that seek understanding are just as powerful and interesting, and perhaps even more so. A growing number of epistemologists are emphasizing the importance of understanding for epistemology, arguing that it should supplant knowledge as the central notion. In this chapter, I bring the literature on understanding in epistemology to bear on (...) explicating the different ways that thought experiments increase three important kinds of understanding: explanatory, objectual and practical. (shrink)

‘Transplant’ thought-experiments, in which the cerebrum is moved from one body to another, have featured in a number of recent discussions in the personal identity literature. Once taken as offering confirmation of some form of psychological continuity theory of identity, arguments from Marya Schechtman and Kathleen Wilkes have contended that this is not the case. Any such apparent support is due to a lack of detail in their description or a reliance on predictions that we are in no (...) position to make. I argue that the case against them rests on two serious misunderstandings of the operation of thought-experiments, and that even if they do not ultimately support a psychological continuity theory, they do major damage to that theory’s opponents. (shrink)

Are thought experiments nothing but arguments? I argue that it is not possible to make sense of the historical trajectory of certain thought experiments if one takes them to be arguments. Einstein and Bohr disagreed about the outcome of the clock-in-the-box thought experiment, and so they reconstructed it using different arguments. This is to be expected whenever scientists disagree about a thought experiment's outcome. Since any such episode consists of two arguments but just one (...) thought experiment, the thought experiment cannot be the arguments. (shrink)

This chapter suggests a scheme of reconstruction, which explains how scenarios, questions and arguments figure in thought experiments. It then develops a typology of ethical thought experiments according to their function, which can be epistemic, illustrative, rhetorical, heuristic or theory-internal. Epistemic functions of supporting or refuting ethical claims rely on metaethical assumptions, for example, an epistemological background of reflective equilibrium. In this context, thought experiments may involve intuitive as well as explicitly argued judgements; they (...) can be used to generate moral commitments, to explore consequences of moral theories, and to show inconsistencies within or between moral commitments and moral theory; but the results of thought experiments by themselves do not settle what is epistemically justified and may also be rejected. Finally, some prominent challenges are discussed: do unrealistic scenarios undermine epistemic thought experiments? Are ethical thought experiments misleading? Do they rely on weak analogies? Are there specifically moral objections to ethical thought experiments? (shrink)

Although thought experiments were first discovered as a sui generis methodological tool by philosophers of science (most prominently by Ernst Mach), the tool can also be found – even more frequently – in contemporary philosophy. Thought experiments in philosophy and science have a lot in common. However, in this chapter we will concentrate on thought experiments in philosophy only. Their use has been the centre of attention of metaphilosophical discussion in the past decade, and (...) this chapter will provide an overview of the results this discussion has achieved and point out which issues are still open. (shrink)

Sorensen presents a general theory of thought experiments: what they are, how they work, what are their virtues and vices. On Sorensen's view, philosophy differs from science in degree, but not in kind. For this reason, he claims, it is possible to understand philosophical thought experiments by concentrating on their resemblance to scientific relatives. Lessons learned about scientific experimentation carry over to thought experiment, and vice versa. Sorensen also assesses the hazards and pseudo-hazards of (...) class='Hi'>thought experiments. Although he grants that there are interesting ways in which the method leads us astray, he attacks most scepticism about thought experiments as arbitrary. They should be used, he says, as they generally are used--as part of a diversified portfolio of techniques. All of these devices are individually susceptible to abuse, fallacy, and error. Collectively, however, they provide a network of cross-checks that make for impressive reliability. (shrink)

: This article seeks to explain how thought experiments work, and also the reasons why they can fail. It is divided into four sections. The first argues that thought experiments in philosophy and science should be treated together. The second examines existing accounts of thought experiments and shows why they are inadequate. The third proposes a better account of thought experiments. According to this account, a thought experimenter manipulates her worldview in (...) accord with the “what if” questions posed by a thought experiment. When all necessary manipulations are carried through, the result is either a consistent model or a contradiction. If a consistent model is achieved, the thought experimenter can conclude that the scenario is possible; if a consistent model cannot be constructed, then the scenario is not possible. The fourth section of the article uses this account to shed light on the circumstances in which thought experiments fail. (shrink)

The paper is a contribution to the debate on the epistemological status of thought experiments. I deal with the epistemological uniqueness of experiments in the sense of their irreducibility to other sources of justification. In particular, I criticize an influential argument for the irreducibility of thought experiments to general arguments. First, I introduce the radical empiricist theory of eliminativism, which considers thought experiments to be rhetorically modified arguments, uninteresting from the epistemological point of (...) view. Second, I present objections to the theory, focusing on the critique of eliminativism by Tamar Szabó Gendler based on the reconstruction of famous Galileo's Pisa experiment. I show that her reconstruction is simplistic and that more elaborate reconstruction is needed for an appropriate assessment of the epistemic power of general argument. I propose such a reconstruction and demonstrate that general version of Pisa experiment is epistemically equal to the particular one. Thus, from an epistemological perspective, Galileo's thought experiment is reducible to a straightforward argument without particular premises. (shrink)

It has been pointed out that Gettier case scenarios have deviant realizations and that deviant realizations raise a difficulty for the logical analysis of thought experiments. Grundmann and Horvath have shown that it is possible to rule out deviant realizations by suitably modifying the scenario of a Gettier-style thought experiment. They hypothesize further that the enriched scenario corresponds to the way expert epistemologists implicitly interpret the original one. However, no precise account of this implicit enrichment is offered, (...) which makes the proposal somewhat ad hoc. Drawing on pragmatic theory, I argue that the content of Grundmann and Horvath’s modified scenario corresponds to the default interpretation of the original scenario and that epistemological expertise is not required to access the deviance-proof interpretation. This Default Interpretation proposal offers thus a more general and independently motivated solution to the Problem of Deviant Realizations. (shrink)

As in science and philosophy, thought experiments in mathematics link a problem to new epistemic resources that are unavailable in a given practice, e.g., Euclidean geometry. Thought experiments invite us to perform an imaginary scenario involving counterfactual, deductive and sensory elements. This chapter aims to pinpoint the beneficial peculiarities of thought experiments in mathematics in comparison with inferences, diagrams and calculative procedures. Reflection about thought experiments assists us to realize both the limits (...) and opportunities in mathematical thinking. Henceforth, the analysis of examples suggests a broader understanding of mathematical, thought and experiment. (shrink)

: While thought experiments play an important role in contemporary analytic philosophy, much remains unclear about thought experiments. In particular, it is still unclear whether the judgments elicited by thought experiments can provide evidence for the premises of philosophical arguments. This article argues that, if an influential and promising view about the nature of the judgments elicited by thought experiments is correct, then many thought experiments in philosophy fail to provide (...) any evidence for the premises of philosophical arguments. (shrink)

Can merely thinking about an imaginary situation provide evidence for how the world actually is--or how it ought to be? In this lively book, Roy A. Sorensen addresses this question with an analysis of a wide variety of thought experiments ranging from aesthetics to zoology. Presenting the first general theory of thought experiment, he sets it within an evolutionary framework and integrates recent advances in experimental psychology and the history of science, with special emphasis on Ernst Mach (...) and Thomas Kuhn. Sorensen explores what thought experiments are, how they work, and what their virtues and vices are. In his view, philosophy differs from science in degree, but not in kind. For this reason, he claims, it is possible to understand philosophical thought experiments by concentrating on their resemblance to scientific relatives. Sorensen assesses the hazards of thought experiments and grants that there are interesting ways in which the method leads us astray, but attacks most scepticism about thought experiments as arbitrary. He maintains that they should be used--as they generally are--as part of a diversified portfolio of techniques, creating a network of cross-checks that make for impressive reliability. (shrink)

This book offers a novel analysis of the widely-used but ill-understood technique of thought experiment. The author argues that the powers and limits of this methodology can be traced to the fact that when the contemplation of an imaginary scenario brings us to new knowledge, it does so by forcing us to make sense of exceptional cases.

What sorts of things are the intuitions generated via thought experiment? Timothy Williamson has responded to naturalistic skeptics by arguing that thought-experiment intuitions are judgments of ordinary counterfactuals. On this view, the intuition is naturalistically innocuous, but it has a contingent content and could be known at best a posteriori. We suggest an alternative to Williamson's account, according to which we apprehend thought-experiment intuitions through our grasp on truth in fiction. On our view, intuitions like the Gettier (...) intuition are necessarily true and knowable a priori. Our view, like Williamson's, avoids naturalistic skepticism. (shrink)

In this piece, I advocate and motivate a new understanding of thought experiments, which avoids problems with the rival accounts of Brown and Norton.

This chapter analyzes the logical structure of Edmund Gettier‐style thought experiments. The discussion can be generalized to many imaginary counterexamples that have been deployed against philosophical analyses and theories in ways more or less similar to Gettier’s. The background working hypothesis is that his thought experiments are paradigmatic, in the sense that if any thought experiments can succeed in philosophy, his do: thus to determine whether Gettier’s thought experiments succeed is in effect (...) to determine whether there can be successful thought experiments in philosophy. Gettier presents his specific counterexamples to the target analysis through short fictional narratives, in the present tense indicative, with fictional uses of proper names, all introduced by “suppose that.” One manifestation of the influence of past experience on epistemological judgments may be cross‐cultural variation in verdicts on thought experiments, including the Gettier case. (shrink)

: An examination of two thought experiments in contemporary physics reveals that the same thought experiment can be reanalyzed from the perspective of different and incompatible theories. This fact undermines those accounts of thought experiments that claim their justificatory power comes from their ability to reveal the laws of nature. While thought experiments do play a genuine evaluative role in science, they do so by testing the nonempirical virtues of a theory, such as (...) consistency and explanatory power. I conclude that, while their interpretation presupposes a whole set of background theories and putative laws, thought experiments nonetheless can evolve and be retooled for different theories and ends. (shrink)

Against Norton's claim that all thought experiments can be reduced to explicit arguments, I defend Brown's position that certain thought experiments yield a priori knowledge. They do this, I argue, not by allowing us to perceive “Platonic universals” (Brown), even though they may contain non-propositional components that are epistemically indispensable, but by helping to identify certain tacit presuppositions or “natural interpretations” (Feyerabend's term) that lead to a contradiction when the phenomenon is described in terms of them, (...) and by suggesting a new natural interpretation in terms of which the phenomenon can be redescribed free of contradiction. (shrink)

I explore the possibility that there are interesting and illuminating paralleIs to be drawn between issues central to the philosophical literature on scientific thought experiments (TE’s) and issues central to the phlilosophical literature on standard fictional narratives. I examine three related questions: (a) To what extent are TE’s (like) standard fictional narratives? (b) Is the understanding of TE’s like the understanding of standard fictional narratives? (c) Most significantly, are there illuminating paralIeIs to be drawn between the ‘epistemological problem’ (...) of TE’s in science, and epistemological problems that attend some of the cognitive claims made for standard works of fiction? If so, are strategies used to defend the epistemic virtues of TE’s equally available to defend the cognitive claims of works of fiction? In addressing the third of these questions, I spell out the range of responses elicited by the epistemological problern of TE’s in science and suggest that at least one of this responses might bear upon the credibility of the cognitive claims of fiction. (shrink)

This is the introduction to the Routledge Companion to Thought Experiments.

Much of the recent movement organized under the heading “Experimental Philosophy” has been concerned with the empirical study of responses to thought experiments drawn from the literature on philosophical analysis. I consider what bearing these studies have on the traditional projects in which thought experiments have been used in philosophy. This will help to answer the question what the relation is between Experimental Philosophy and philosophy, whether it is an “exciting new style of [philosophical] research”, “a (...) new interdisciplinary field that uses methods normally associated with psychology to investigate questions normally associated with philosophy” (Knobe et al. 2012), or whether its relation to philosophy consists, as some have suggested, in no more than the word ‘philosophy’ appearing in its title, or whether the truth lies somewhere in between these two views. I first distinguishes different strands in Experimental Philosophy, negative and positive x-phi, and x-phi pursuing philosophy as opposed to x-phi as cognitive science. Next I review some ways in which Experimental Philosophy has been criticized. Finally, I consider what would have to be true for Experimental Philosophy to have one or another sort of relevance to philosophy, whether the assumptions required are true, how we could know it, and the ideal limits of the usefulness Experimental Philosophy to philosophy. I conclude x-phi cannot in principle be a replacement for traditional first person approaches because it yields the wrong kind of knowledge and that it can nonetheless be a practical aid in conducting philosophical thought experiments. n. (shrink)

In 1969 Harry Frankfurt published his hugely influential paper 'Alternate Possibilities and Moral Responsibility' in which he claimed to present a counterexample to the so-called 'Principle of Alternate Possibilities' ('a person is morally responsible for what he has done only if he could have done otherwise'). The success of Frankfurt-style cases as counterexamples to the Principle has been much debated since. I present an objection to these cases that, in questioning their conceptual cogency, undercuts many of those debates. Such cases (...) all require a counterfactual mechanism that could cause an agent to perform an action that he cannot avoid performing. I argue that, given our concept of what it is for someone to act, this requirement is inconsistent. Frankfurt-style alleged counterexamples are cases where an agent is morally responsible for an action he performs even though, the claim goes, he could not have avoided performing that action. However, it has recently been argued, e.g. by John Fischer, that a counterexample to the Principle could be a 'Fischer-style case', i.e. a case where the agent can either perform the action or do nothing else. I argue that, although Fischer-style cases do not share the conceptual flaw common to all Frankfurt-style cases, they also fail as counterexamples to the Principle. The paper finishes with a brief discussion of the significance of the Principle of Alternate Possibilities. (shrink)

What is the nature of the evidence provided by thought experiments in philosophy? For instance, what evidence is provided by the Gettier thought experiment against the JTB theory of knowledge? According to one view, it provides as evidence only a certain psychological proposition, e.g. that it seems to one that the subject in the Gettier case lacks knowledge. On an alternative, nonpsychological view, the Gettier thought experiment provides as evidence the nonpsychological proposition that the subject in (...) the Gettier case lacks knowledge (e.g., Williamson 2007). Given the centrality of thought experiments to philosophical enquiry, the correct account of thought experiment evidence is important for understanding the nature of philosophical methodology. Further, Williamson argues that a misguided adherence to the psychological view of thought experiment evidence encourages scepticism about philosophy since it opens a gap between our evidence and the nonpsychological subject matter of philosophy. The main aim of this paper is to defend the psychological view against recent objections. In particular, I argue that even if thought experiment evidence is psychological, it can still provide justification for non-psychological claims which are the subject matter of philosophy. (shrink)

Should we descry the nature of the self from thought experiments? Shaun Nichols says ‘maybe,’ but only if we use thought experiments that do not recruit the indexical “I” (non-I-recruiting). His reason is that the psychology of “I” perforce mandates that imagination responds to thought experiments that recruit it (I-recruiting) peculiarly. Here, I consider whether he is correct about non-I-recruiting personal identity thought experiments. I argue positively using the same framework, i.e., considering (...) the underlying psychology. (shrink)

Good physical experiments conform to the basic methodological standards of experimental design: they are objective, reliable, and valid. But is this also true of thought experiments? Especially problems of personal identity have engendered hypothetical scenarios that are very distant from the actual world. These imagined situations have been conspicuously ineffective at resolving conflicting intuitions and deciding between the different accounts of personal identity. Using prominent examples from the literature, I argue that this is due to many of (...) these thought experiments not adhering to the methodological standards that guide experimental design in nearly all other disciplines. I also show how empirically unwarranted background assumptions about human physiology render some of the hypothetical scenarios that are employed in the debate about personal identity highly misleading. (shrink)

In this book, Sorensen presents the first general theory of the thought experiment. He analyses a wide variety of thought experiments, ranging from aesthetics to zoology, and explores what thought experiments are, how they work, and what their positive and negative aspects are. Sorensen also sets his theory within an evolutionary framework and integrates recent advances in experimental psychology and the history of science.

Let's begin with an old example. In De Rerum Naturua , Lucretius presented a thought experiment to show that space is infinite. We imagine ourselves near the alleged edge of space; we throw a spear; we see it either sail through the ‘edge’ or we see it bounce back. In the former case the ‘edge’ isn't the edge, after all. In the latter case, there must be something beyond the ‘edge’ that repelled the spear. Either way, the ‘edge’ isn't (...) really an edge of space, after all. So space is infinite. (shrink)

The method of thought experiments or possible cases is widespread in philosophy and elsewhere. Thought experiments come with variegated theoretical commitments. These commitments are risky. They may turn out to be false or at least controversial. Other things being equal, it seems preferable to do with minimal commitments. I explore exemplary ways of minimising commitments, focusing on modal ones. There is a near-consensus to treat the scenarios considered in thought experiments as metaphysical possibilities. I (...) challenge this consensus. Paradigmatic thought experiments do not have to come with a commitment to metaphysical possibilities. In the first section, I point out difficulties with the prevailing focus on metaphysical possibilities. In the second section, I present alternative formalisations of a paradigmatic thought experiment, the Gettier experiment. Gettier’s words leave open the kind of possibilities under consideration. The standard way of spelling out Gettier’s argument uses metaphysical possibilities. One alternative proposal uses nomological possibilities. A second one uses epistemic possibilities. My modest conclusion: as long as it is not established that a thought experiment requires a commitment to metaphysical modality, one should avoid such a commitment. My preferred way of doing so is to replace the commitment to one particular formalisation by a commitment to a disjunction of alternative formalisations. (shrink)

The growing literature on philosophical thought experiments has so far focused almost exclusively on the role of thought experiments in confirming or refuting philosophical hypotheses or theories. In this paper we draw attention to an additional and largely ignored role that thought experiments frequently play in our philosophical practice: some thought experiments do not merely serve as means for testing various philosophical hypotheses or theories, but also serve as facilitators for conceiving and (...) articulating new ones. As we will put it, they serve as ‘heuristics for theory discovery’. Our purpose in the paper is two-fold: to make a case that this additional role of thought experiments deserves the attention of philosophers interested in the methodology of philosophy; to sketch a tentative taxonomy of a number of distinct ways in which philosophical thought experiments can aid theory discovery, which can guide future research on this role of thought experiments. (shrink)

Thought experiments are ubiquitous in science and especially prominent in domains in which experimental and observational evidence is scarce. One such domain is the causal analysis of singular events in history. A long‐standing tradition that goes back to Max Weber addresses the issue by means of ‘what‐if’ counterfactuals. In this paper I give a descriptive account of this widely used method and argue that historians following it examine difference makers rather than causes in the philosopher’s sense. While difference (...) making is neither necessary nor sufficient for causation, to establish difference makers is more consistent with the historians’ more ultimate purposes. †To contact the author, please write to: Department of Philosophy, Erasmus University, 3000 DR Rotterdam, The Netherlands; e‐mail: [email protected]. (shrink)

Thought experiments being central to contemporary philosophy and science, the following questions were asked in recent literature. What is their definition? Are they heuristic devices, arguments, paradoxes? Are they comparable to real experiments? Do intuition and conceivability intervene? Equally imaginative thought experiments are found in ancient, medieval, and Renaissance texts. Paying attention to prime historical examples of thought experiments, we show that historical perspectives help answer these general questions.

African perspectives on personhood and personal identity and their relation to those of the West have become far more central in mainstream Western discussion than they once were. Not only are African traditional views with their emphasis on the importance of community and social relations more widely discussed, but that emphasis has also received much wider acceptance and gained more influence among Western philosophers. Despite this convergence, there is at least one striking way in which the discussions remain apart and (...) that is on a point of method. The Western discussion makes widespread use of thought experiments. In the African discussion, they are almost entirely absent. In this article, we put forward a possible explanation for the method of thought experiment being avoided that is based on considerations stemming from John Mbiti’s account of the traditional African view of time. These considerations find an echo in criticism offered of the method in the Western debate. We consider whether a response to both trains of thought can be found that can further bring the Western and African philosophical traditions into fruitful dialogue. (shrink)

Unlike in physics, the category of thought experiment is not very common in biology. At least there are no classic examples that are as important and as well-known as the most famous thought experiments in physics, such as Galileo’s, Maxwell’s or Einstein’s. The reasons for this are far from obvious; maybe it has to do with the fact that modern biology for the most part sees itself as a thoroughly empirical discipline that engages either in real natural (...) history or in experimenting on real organisms rather than fictive ones. While theoretical biology does exist and is recognized as part of biology, its role within biology appears to be more marginal than the role of theoretical physics within physics. It could be that this marginality of theory also affects thought experiments as sources of theoretical knowledge. Of course, none of this provides a sufficient reason for thinking that thought experiments are really unimportant in biology. It is quite possible that the common perception of this matter is wrong and that there are important theoretical considerations in biology, past or present, that deserve the title of thought experiment just as much as the standard examples from physics. Some such considerations may even be widely known and considered to be important, but were not recognized as thought experiments. In fact, as we shall see, there are reasons for thinking that what is arguably the single most important biological work ever, Charles Darwin’s On the Origin of Species, contains a number of thought experiments. There are also more recent examples both in evolutionary and non-evolutionary biology, as we will show. Part of the problem in identifying positive examples in the history of biology is the lack of agreement as to what exactly a thought experiment is. Even worse, there may not be more than a family resemblance that unifies this epistemic category. We take it that classical thought experiments show the following characteristics: They serve directly or indirectly in the non-empirical epistemic evaluation of theoretical propositions, explanations or hypotheses. Thought experiments somehow appeal to the imagination. They involve hypothetical scenarios, which may or may not be fictive. In other words, thought experiments suppose that certain states of affairs hold and then try to intuit what would happen in a world where these suppositions are true. We want to examine in the following sections if there are episodes in the history of biology that satisfy these criteria. As we will show, there are a few episodes that might satisfy all three of these criteria, and many more if the imagination criterion is dropped or understood in a lose sense. In any case, this criterion is somewhat vague in the first place, unless a specific account of the imagination is presupposed. There will also be issues as to what exactly “non-empirical” means. In general, for the sake of discussion we propose to understand the term “thought experiment” here in a broad rather than a narrow sense here. We would rather be guilty of having too wide a conception of thought experiment than of missing a whole range of really interesting examples. (shrink)

The philosophical literatures on models and thought experiments have been developing exponentially, and independently, for decades. This independence is surprising, given how similar models and thought experiments are. They each have “lives of their own,” they sit between theory and experience, they are important for both pedagogy and cutting-edge science, they galvanize conceptual changes and paradigm shifts, and they involve entertaining imaginary scenarios and working out what happens. Recently, philosophers have begun to highlight these similarities. This (...) entry aims at taking the idea further, by trying to systematically identify places where insights from one literature can be taken up in the other. Along the way, important differences will also be highlighted. (shrink)

We need only list a few of the well‐known thought experiments to be reminded of their enormous influence and importance in the sciences: Newton's bucket, Maxwell's demon, Einstein's elevator, Heisenberg's gamma‐ray microscope, Schrödinger's cat. The seventeenth century saw some of its most brilliant practitioners in Galileo, Descartes, Newton, and Leibniz. And in our own time, the creation of quantum mechanics and relativity are almost unthinkable without the crucial role played by thought experiments.

Experimental ethicists investigate traditional ethical questions with non-traditional means, namely with the methods of the empirical sciences. Studies in this area have made heavy use of philosophical thought experiments such as the well-known trolley cases. Yet, the specific function of these thought experiments within experimental ethics has received little consideration. In this paper we attempt to fill this gap. We begin by describing the function of ethical thought experiments, and show that these thought (...) experiments should not only be classified according to their function but also according to their scope. On this basis we highlight several ways in which the use of thought experiments in experimental ethics can be philosophically relevant. We conclude by arguing that experimental philosophy currently only focuses on a small subcategory of ethical thought experiments and suggest a broadening of its research agenda. (shrink)

This paper replies to objections that have been raised against my operational-Kantian account of thought experiments by Fehige 2012 and 2013. Fehige also sketches an alternative Neo-Kantian account that utilizes Michael Friedman’s concept of a contingent and changeable a priori. To this I shall reply, first, that Fehige’s objections not only neglect some fundamental points I had made as regards the realizability of TEs, but also underestimate the principle of empiricism, which was rightly defended by Kant. Secondly, in (...) opposition to what he states, my account does not differ in a very essential way from the empiricist solutions either as regards the power of TEs to predict something new about empirical reality, or as regards the criteria for telling apart good from bad TEs. Thirdly, in the light of the Kantian definition of the a priori, Friedman’s corresponding notion is contrary both to the spirit and to the letter of Kant’s philosophy; moreover, from a theoretical point of view, a material a priori is theoretically untenable since, counter to Friedman’s own intentions, it leads to relativism. -/- . (shrink)

The operational perspective here defended permits a reflexive-transcendental point of view that sharply distinguishes the two concepts, while, at the same time, maintaining the connection between them. On the one hand, simply imagining that the experimental apparatus, counterfactually anticipated in a thought experiment, has really been constructed is sufficient to erase any difference between thought and real experiments. On the other hand, this very ‘imagining’, this capacity of the mind to assume every real entity as a possible (...) entity, underpins the difference in principle – a properly transcendental difference – between thought and real experiments. This difference, however, implies the intimate association between experiment and thought experiment: All thought experiments must be thought of as translatable into real ones, and all real experiments as realisations of thought ones. What thought experiments have over and above real experiments is the mere fact that they exist in a purely hypothetical sphere; what real have over and above thought experiments is the mere fact that they overstep the sphere of the possible, in the experiment’s real execution. (shrink)

Most disciplines make use of thought experiments, but physics and philosophy lead the pack with heavy dependence upon them. Often this is for conceptual clarification, but occasionally they provide real theoretical advances. In spite of their importance, however, thought experirnents have received rather little attention as a topic in their own right until recently. The situation has improved in the past few years, but a mere generation ago the entire published literature on thought experiments could (...) have been mastered in a long weekend. Now the subject is beginning to flourish. Given the relative newness of the field, it might be useful to have several examples at one’s finger tips, so a number of great ones will be described. Attention will also be drawn outside physics and philosophy. In mathematics there is something analogous to thought experiments -- visual reasoning and picture proofs. I will look briefly at this class of thought experiments and try using them to make a case for possibly settling the continuum hypothesis. After this, I will return to thought experiments in the sciences and propose an account of how they work. Finally, I will end with a sketch of a topic I am currently working on, a kind of progress report which, I hope, will be an inducement to others. (shrink)

The paper aims to offer an account of the cognitive capacities involved in judgements about thought experiments, without appealing to the notions of analyticity or intuition. I suggest that we employ a competence in the application of the relevant concepts. In order to address the worry that this suggestion is not explanatory, I look at some theories of concepts discussed in psychology, and I use them to illustrate how such competence might be realized. This requires, crucially, distinguishing between (...) concepts and ways of applying concepts, or conceptions. I end by considering a possible objection and comparing my account with a similar one defended by David Papineau. (shrink)

Despite their centrality and importance to both science and philosophy, relatively little has been written about thought experiments. This volume brings together a series of extremely interesting studies of the history, mechanics, and applications of this important intellectual resource. A distinguished list of philosophers and scientists consider the role of thought experiments in their various disciplines, and argue that an examination of thought experimentation goes to the heart of both science and philosophy.

Thought experiments are profitably compared to compasses. A compass is a simple but useful device for determining direction. Nevertheless, it systematically errs in the presence of magnets ...it becomes unreliable near the North Pole, in mine shafts, when vibrated, in the presence of metal ...experts will wish to use the compass as one element in a wider portfolio of navigational techniques. Analogously, thought experiments are simple but useful devices for determining the status of propositions. Sadly, they (...) systematically err under certain conditions and so are best used with sensitivity to their foibles and limited scope (Sorensen, 1992, pp. 288–289). (shrink)

Thought experiments are ordinary argumentation disguised in a vivid pictorial or narrative form. This account of their nature will allow me to show that empiricism has nothing to fear from thought experiments. They perform no epistemic magic. In so far as they tell us about the world, thought experiments draw upon what we already know of it, either explicitly or tacitly; they then transform that knowledge by disguised argumentation. They can do nothing more epistemically (...) than can argumentation. I defend my account of thought experiments in Section 3 by urging that the epistemic reach of thought experiments turns out to coincide with that of argumentation and that this coincidence is best explained by the simple view that thought experiments just are arguments. Thought experiments can err—-a fact to be displayed by the thought experiment - anti thought experiment pairs of Section 2. Nonetheless thought experiments can be used reliably and, I urge in Section 4., this is only possible if they are governed by some very generalized logic. I will suggest on evolutionary considerations that their logics are most likely the familiar logics of induction and deduction, recovering the view that thought experiment is argumentation. Finally in Section 5 I defend this argument based epistemology of thought experiments against competing accounts. I suggest that these other accounts can offer a viable epistemology only insofar as they already incorporate the notion that thought experimentation is governed by a logic, possibly of very generalized form. (shrink)

It is widely presumed that intuitions about thought experiments can help overturn philosophical theories. It is also widely presumed, albeit implicitly, that if thought experiments play any epistemic role in overturning philosophical theories, it is via intuition. In this paper, I argue for a different, neglected epistemic role of philosophical thought experiments, that of improving some reasoner’s appreciation both of what a theory’s predictions consist in and of how those predictions tie to elements of (...) the theory. I call this role theory clarification. I show that theory clarification does not proceed via intuition, and I argue that it is only in conjunction with theory clarification that intuitions about thought experiments can help overturn philosophical theories. I close by sketching how a more radical view might be true, on which thought experiments help justify the rejection of philosophical theories exclusively by clarifying theories, not by any intuitions those thought experiments might generate. (shrink)

The literature on thought experiments has been mainly concernedwith thought experiments that are directed at a theory, be it in aconstructive or a destructive manner. This has led somephilosophers to argue that all thought experiments can beformulated as arguments. The aim of this paper is to drawattention to a type of thought experiment that is not directed ata theory, but fulfills a specific function within a theory. Suchthought experiments are referred to as (...) functional thoughtexperiments, and they are routinely used in applied statistics. An example is given from frequentist statistics, where a thoughtexperiment is required to establish the probability space. It isconcluded that (a) not all thought experiments can be formulated asarguments, and (b) the role of thought experiments is more generaland more important to scientific reasoning than has previouslybeen recognized. (shrink)

Thought experiments in science are merely picturesque argumentation. I support this view in various ways, including the claim that it follows from the fact that thought experiments can err but can still be used reliably. The view is defended against alternatives proposed by my cosymposiasts.