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)

I argue that Plato’s use of thought experiments anticipate many of the themes discussed by Thomas S. Kuhn’s classic essay, “A Function for Thought Experiments.” Kuhn’s concern is that thought experiments satisfy the condition of verisimilitude. That is, thought experiments must not be conducted merely to alter the conceptual apparatus of the scientist regarding the phenomenon explored, but rather to alter the scientist’s conceptual apparatus for the sake of altering his actions (i.e., practical rationality). Plato, too, is quite concerned with (...) getting interlocutors to appreciate that theory not be separated from practice, and that theory is necessary for the process of effective decision making. Each of the interlocutors presented in the Republic, Apology and Alcibiades Minor are confrontedwith a thought experiment that is designed to effect how they choose to live. Although the three dialogues I discuss illustrate the Kuhnian admonishment against separating theory form practice, many other dialogues in the Platonic corpus echo Kuhn’s concerns. (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)

My theme is thought experiment in natural science, and its relation to real experiment. I shall defend the thesis that thought experiments that do not lead to theorizing and to a real experiment are generally of much less value that those that do so. To illustrate this thesis I refer to three examples, from three very different periods, and with three very different kinds of status. The first is the classic thought experiment in which Galileo imagined that he had, by (...) pure thought, demolished Aristoteles' dogma that heavier bodies fall more quickly than light ones. I will show that he was mistaken. The second is the Einstein-Podolsky-Rosen paper purporting to show that quantum mechanics must be incomplete in its domain of application. This thought experiment is a very good one, not because its conclusions are correct, but precisely because it was fruitful, leading to theory and, above all, to a real experiment. Finally I discuss the modern string theory of everything, which, while it is regarded as a physical theory by its instigators, shares some properties of the least successful sort of thought experiment. (shrink)

We have never entirely agreed with Daniel Cohnitz on the status and rôle of thought experiments. Several years ago, enjoying a splendid lunch together in the city of Ghent, we cheerfully agreed to disagree on the matter; and now that Cohnitz has published his considered opinion of our views, we are glad that we have the opportunity to write a rejoinder and to explicate some of our disagreements. We choose not to deal here with all the issues that Cohnitz raises, (...) but rather to restrict ourselves to three specific points. (shrink)

A characteristic of contemporary analytic philosophy is its ample use of thought experiments. We formulate two features that can lead one to suspect that a given thought experiment is a poor one. Although these features are especially in evidence within the philosophy of mind, they can, surprisingly enough, also be discerned in some celebrated scientific thought experiments. Yet in the latter case the consequences appear to be less disastrous. We conclude that the use of thought experiments is more successful in (...) science than in philosophy. (shrink)

Both entertaining and startling, The Pig That Wants to Be Eaten offers one hundred philosophical puzzles that stimulate thought on a host of moral, social, and personal dilemmas. Taking examples from sources as diverse as Plato and Steven Spielberg, author Julian Baggini presents abstract philosophical issues in concrete terms, suggesting possible solutions while encouraging readers to draw their own conclusions: Lively, clever, and thought-provoking, The Pig That Wants to Be Eaten is a portable feast for the mind that is sure (...) to satisfy any intellectual appetite. BACKCOVER: “Thinking again is what this taut, incisive, bullet-hard book is dedicated to promoting.” —The Sunday Times (London) “This book is like the Sudoku of moral philosophy: apply your mind to any of its ‘thought experiments’ while stuck on the Tube, and quickly be transported out of rush-hour hell.” —New Statesman. (shrink)

This book includes experiments that cover identity, religion, art, ethics, language, knowledge and more.

This essay concerns the question of how we make genuine epistemic progress through conceptual analysis. Our way into this issue will be through consideration of the paradox of analysis. The paradox challenges us to explain how a given statement can make a substantive contribution to our knowledge, even while it purports merely to make explicit what one’s grasp of the concept under scrutiny consists in. The paradox is often treated primarily as a semantic puzzle. However, in “Sect. 1” I argue (...) that the paradox raises a more fundamental epistemic problem, and in “Sects.1 and 2” I argue that semantic proposals—even ones designed to capture the Fregean link between meaning and epistemic significance—fail to resolve that problem. Seeing our way towards a real solution to the paradox requires more than semantics; we also need to understand how the process of analysis can yield justification for accepting a candidate conceptual analysis. I present an account of this process, and explain how it resolves the paradox, in “Sect. 3”. I conclude in “Sect. 4” by considering the implications for the present account concerning the goal of conceptual analysis, and by arguing that the apparent scarcity of short and finite illuminating analyses in philosophically interesting cases provides no grounds for pessimism concerning the possibility of philosophical progress through conceptual analysis. (shrink)

While theories about interpreting biblical and other parables have long realised the importance of readers’ responses to the topic, recent results in social psychology concerning systematic self-deception raise unforeseen problems. In this paper I first set out some of the problems these results pose for the authority of fictional thought-experiments in moral philosophy. I then consider the suggestion that biblical parables face the same problems and as a result cannot work as devices for moral or religious instruction in the way (...) that they are usually understood to work. I examine a number of influential theories about interpretation of the parables which might appear to deflect the problems, and argue that none of them are ultimately successful in doing so. (shrink)

Philosophers have traditionally used thought-experiments in their endeavours to find a satisfactory account of the self and personal identity. Yet there are considerations from empirical psychology as well as related ones from philosophy itself that appear to completely undermine the method of thought-experiment. This paper focuses on both sets of considerations and attempts a defence of the method.

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)

: 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)

In this paper a unified theory of models and thought experiments is proposed by considering them as fictions, la Vaihinger. In order to reach this aim, the Hertzian and Botzmannian interpretation of theories as Bilder is reconsidered.

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)

I begin with an explication of "thought experiment". I then clarify the role that intuitions play in thought experiments by addressing two important issues: (1) the informativeness of thought experiments and (2) the legitimacy of the method of thought experiments in philosophy and the natural sciences. I defend a naturalistic account of intuitions that provides a plausible explanation of the informativeness of thought experiments, which, in turn, allows thought experiments to be reconstructed as arguments. I also specify criteria for distinguishing (...) bad "intuition pumps" from legitimate thought experiments. These criteria help us to avoid being seduced by the dangerous suggestive power of misleading intuitions. (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 experiments 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 book concludes with chapters on the nature of Einstein's work and on the interpretation of quantum mechanics which stand as a test of the author's central ...

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)

In this paper I argue that (at least many) philosophical thought experiments are unreliable. But I argue that this notion of unreliability has to be understood relative to the goal of thought experiments as knowledge producing. And relative to that goal many thought experiments in science are just as unreliable. But in fact thought experiments in science play a varied role and I will suggest that knowledge production is a goal only under quite limited circumstances. I defend the view that (...) these circumstances can (sometimes) arise in philosophy as well. (shrink)

On the relation between experiment and thought experiment in the natural sciences. To understand the reciprocal autonomy and complementarity of thought and real experiment, it is necessary to distinguish between a ‘positive’ (empirical or formal) and a transcendental perspective. Empirically and formally, real and thought experiments are indistinguishable. However, from a reflexive-transcendental viewpoint thought experiment is at the same time irreducible and complementary to real experiment. This is due to the fact that the hypothetical-anticipatory moment is in principle irreducible to (...) physical reality—even though it refers to physical reality and is bound with the empirical use of our understanding. The presence of counterfactuals is the condition of the possibility for thought experiments to become in principle real ones, by means of a series of technical realisations that gradually approximate the idealisations that they contain. (shrink)

In the present essay, I aim to accentuate an analogy between the patterns of thought articulated by Berkeley's Hylas and those of Nagel in his philosophy of bats and aliens. The comparison has a critical purpose, with Philonous playing a role similar to that of Wittgenstein. I argue that Nagel's central claim comes down to statements that are marked by a peculiar form of emptiness. Towards the end, though, I will concede that this kind of Wittgensteinian criticism runs up against (...) certain limits. The fantasies produced by Hylas or Nagel have as counterparts genuine philosophical expressions of experience, which are not vulnerable to the charges levelled at their theoretical parallels. (shrink)

Recently, philosophers have discovered that they have a lot to learn from, or at least to ponder about, fiction. Many metaphysicians are attracted to fiction as a model for our talk about purported objects and properties, such as numbers, morality, and possible worlds, without embracing a robust Platonist ontology. In addition, a growing group of philosophers of mind are interested in the implications of our engagement with fiction for our understanding of the mind and emotions: If I don’t believe that (...) Anna Karenina exists, can I really pity her, or hope or desire that she extricate herself from her tragic situation? And why is there no “morality fiction,” analogous to science fiction? I suspect that philosophers have been especially comfortable thinking about fiction because it seems, at least prima facie, to employ the imagination in a way that conforms to a standard model of the mind. Specifically, contemporary philosophers tend to think of imagination as a form of mental pretense. Mental pretense can take two main forms: a cognitive attitude of supposing a set of propositions to be true (make-believe) or else an experiential state of imaging a scenario as if it were before one (imaging). Much of our pretense intertwines the cognitive and experiential modalities, of course. But both share a crucial common feature: all of one’s imaginative effort is invested in pretending that certain contents obtain. In this sense, we can understand imagination as the “offline” simulation of actual beliefs and perceptions (and perhaps other attitudes as well), where we analyze these in the normal way, as states individuated by their attitude and representational content. While I share the burgeoning interest in fiction, I want to suggest that we also have a lot to learn from poetry, and in particular from poetic metaphor. I will argue.. (shrink)

A is for Alice and astronomers arguing about acceleration -- B is for Bernard's body-exchange machine -- C is for the Catholic cannibal -- D is for Maxwell's demon -- E is for evolution (and an embarrassing problem with it) -- F is for the forms lost forever to the prisoners of the cave -- G is for Galileo's gravitational balls -- H is for Hume's shades -- I is for the identity of indiscernibles -- J is for Henri Poincaré (...) and alternative geometries -- K is for the Kritik and Kant's kind of thought experiments -- L is for Lucretius' spear -- M is for Mach's motionless chain -- N is for Newton's bucket -- O is for Olbers' paradox -- P is for Parfit's person -- Q is for the questions raised by thought experiments quotidiennes -- R is for the rule-ruled room -- S is for Salvatius' ship, sailing along its own space-time line -- T is for the time-travelling twins -- U is for the universe, and Einstein's attempts to understand it -- V is for the vexed case of the violinist -- W is for Wittgenstein's beetle -- X is for xenophanes and thinking by examples -- Y is for counterfactuals and a backwards approach to history -- Z is for Zeno and the mysteries of infinity. (shrink)

In their paper, ‘When are thought experiments poor ones?’ (Peijnenburg and Atkinson 2003), Jeanne Peijnenburg and David Atkinson argue that most, if not all, philosophical thought experiments are “poor” ones with “disastrous consequences” and that they share the property of being poor with some (but not all) scientific thought experiments. Noting that unlike philosophy, the sciences have the resources to avoid the disastrous consequences, Peijnenburg and Atkinson come to the conclusion that the use of thought experiments in science is in (...) general more successful than in philosophy and that instead of concocting more “recherché” thought experiments, philosophy should try to be more empirical. (shrink)

Egal was der heutige Tag auch bringen mag, der 1. April 2063 wird zumindest als der Tag in die Geschichte des Wissenschaftsjournalismus eingehen, der die bisher aufwändigste Berichterstattung erfahren hat. So viele Kamerateams, wie hier vor den Toren der Australian National University in Canberra, hat bisher kein wissenschaftliches Experiment anziehen können. Selbst der Knüller des Vorjahres, als es einer 48jährigen Hausfrau in einem Vorort von London gelang, mit einfachsten Küchenutensilien einen kleinen Kalte-Fusion-Reaktor herzustellen, der den Staubsauger und die Mikrowelle zuverlässig (...) mit sauberer Energie versorgte, hatte bei weitem nicht ein solches Echo in der Wissenschaftspresse erfahren. Es war zwar noch nichts über den Experimentausgang zu erfahren, trotzdem wurde freilich seit drei Tagen ununterbrochen live auf fast allen Kanälen aus Canberra darüber berichtet, dass nun zwar noch nichts zu erfahren sei, dass es aber ja sehr bald soweit sein müsse. Das Experiment, dessen Ausgang man hier so gespannt erwartete, war schon im Vorfeld hitzig diskutiert worden und überhaupt nur durch einen Sonderbeschluss der Vereinten Nationen zustande gekommen. Immerhin läuft die Vorbereitung bereits seit fast 30 Jahren, als sich mehrere Philosophen und Bürgerinitiativen zusammenschlossen, die UNO um eine endgültige Klärung einer der ältesten Fragen der Menschheit zu bitten: Was ist Bewusstsein? Und insbesondere: Ist Bewusstsein etwas anderes als physikalisch beschreibbare Zustände unseres Gehirns, oder sind alle Tatsachen letztlich physikalische Tatsachen? Dass diese Fragen trotz ihres Ehrfurcht einflößenden Alters zunehmend auf den Nägeln brannten, hatte nicht zuletzt die jüngste Entwicklung der Computertechnologie befördert. Nachdem die KI in den letzten Jahrzehnten einen großen Schritt vorwärts gemacht hatte, war man in Sorge, dass ohne endgültige begriffliche Klärung dieser Fragen unser zukünftiger Umgang mit unseren elektronischen Helfern auf moralisch unsicherem Boden stehen könne. Man hatte sich daher nach langer Abwägung der ethischen Aspekte dieses Experiments dazu entschieden, ein gerade neugeborenes Waisenkind in einem völlig schwarz-weiß-grauen Raum groß werden zu lassen, sorgsam darum bemüht, dass die kleine Mary (so hatte man das Mädchen in Anlehnung an die Protagonistin einer fiktiven philosophischen Geschichte genannt) keine Farben zu Gesicht bekommt.. (shrink)

In their paper, 'When are thought experiments poor ones?' (Peijnenburg and Atkinson, 2003, Journal of General Philosophy of Science 34, 305-322), Jeanne Peijnenburg and David Atkinson argue that most, if not all, philosophical thought experiments are "poor" ones with "disastrous consequences" and that they share the property of being poor with some (but not all) scientific thought experiments. Noting that unlike philosophy, the sciences have the resources to avoid the disastrous consequences, Peijnenburg and Atkinson come to the conclusion that the (...) use of thought experiments in science is in general more successful than in philosophy and that instead of concocting more "recherché" thought experiments, philosophy should try to be more empirical. In this comment I will argue that Peijnenburg's and Atkinson's view on thought experiments is based on a misleading characterization of both, the dialectical situation in philosophy as well as the history of physics. By giving an adequate account of what the Discussion in contemporary philosophy is about, we will arrive at a considerably different evaluation of philosophical thought experiments. (shrink)

One of the most basic methods of philosophy is, and has always been, the consideration of counterfactual cases and imaginary scenarios. One purpose of doing so obviously is to test our theories against such counterfactual cases. Although this method is widespread, it is far from being commonly accepted. Especially during the last two decades it has been confronted with criticism ranging from complete dismissal to denying only its critical powers to a cautious defense of the use of thought experiments as (...) counterexamples. One of the strongest criticisms of the method of thought experimentation is "modal skepticism" as explicated and defended by Peter van Inwagen. Van Inwagen argues that the philosopher's notion of logical possibility is confused and that its epistemology is dubious. I argue that van Inwagen's skepticism is unwarranted. There is a sufficiently clear notion of logical possibility and a sufficiently straightforward way of getting to know what is logically possible. In the remainder of the paper I show how that connects with the methodology of thought experimentation in philosophy. (shrink)

Sie halten gerade ein Buch in Ihren H¨anden. Vielleicht liegt es auch auf dem Tisch vor Ihnen, w¨ahrend Sie diese Worte lesen. Aber woher wissen Sie, dass Sie ein Buch vor sich haben? Nun, Sie sehen es nat¨urlich mit eigenen Augen. Vermutlich f¨uhlen Sie auch das Gewicht des Buches, das gegen Ihre Haut dr¨uckt, w¨ahrend sie es in H¨anden halten, und h¨oren das Rascheln der Seiten, wenn Sie umbl¨attern. Dar¨uber hinaus sind Sie wach und (so vermuten wir mal) einigermaßen n¨uchtern, (...) also in einem Zustand, in dem Sie f¨ur gew¨ohnlich Ihren Sinnen vertrauen. Da Sie von diesen zuverl¨assigen Quellen, die Sie st¨andig ¨uber Sie und Ihre Umgebung auf dem Laufenden halten, mit diesen Informationen ¨ubersch¨uttet werden und da diese zuverl¨assigen Quellen Ihnen nun mitteilen, dass Sie ein Buch in H¨anden halten, hegen Sie dar¨uber nicht den geringsten Zweifel. (shrink)

Practitioners of the new ‘experimental philosophy’ have collected data that appear to show that some philosophical intuitions are culturally variable. Many experimental philosophers take this to pose a problem for a more traditional, ‘armchair’ style of philosophizing. It is argued that this is a mistake that derives from a false assumption about the character of philosophical methods; neither philosophy nor its methods have anything to fear from cultural variability in philosophical intuitions.

In their delightfully provocative paper, “Semantics, Cross-Cultural Style,” Edouard Machery, Ron Mallon, Shaun Nichols, and Stephen Stich (2004),[1] make several striking claims about theories of reference. First, they claim: (I) Philosophical views about reference “are assessed by consulting one’s intuitions about the reference of terms in hypothetical situations” (p. B1). This claim is prompted by their observations of the role of intuitions in Saul Kripke’s refutation of the descriptivist view of proper names in favor of a causal-historical view (1980). The (...) particular intuitions they attend to are those aired in discussing Kripke’s cases of Gödel and Jonah. This prompts the next claim: (II) Those particular cases are “central” to Kripke’s refutation (p. B1). Indeed, Machery et al describe these cases as “some of the most influential thought experiments in the philosophy of reference” (p. B8). Inspired by recent work in psychology (e.g., Nisbett et al 2001) that shows “systematic cognitive differences between East Asians and Westerners” (p. B1), Machery et al predicted that there would be cultural differences in referential intuitions. They conducted some ingenious experiments on Gödel and Jonah cases to test this predication. The results in the Gödel cases, although not in the Jonah cases, confirmed their prediction, leading them to conclude: “Westerners are more likely than East Asians to report intuitions that are consistent with the causal-historical view” (p. B1). And, implicitly, they claim: (III) These results raise serious doubts about Kripke’s refutation, which relies solely on the intuitions of Westerners. They are explicit about the following bolder claim: (IV) The fact of these cultural differences “raises questions about the nature of the philosophical enterprise of developing a theory of reference” (p. B1); it points to “significant philosophical conclusions” (p.. (shrink)

Frank Jackson has argued that only if we have a priori knowledge of the extension-fixers for many of our terms can we vindicate the methodological practice of relying on intuitions to decide between philosophical theories. While there has been much discussion of Jackson's claim that we have such knowledge, there has been comparatively little discussion of this most powerful argument for that claim. Here I defend an alternative explanation of our intuitions about possible cases, one that does not rely on (...) a priori extension-fixers. This alternative explanation provides a vindication of our reliance on intuitions, while blocking Jackson's abductive argument for a priori semantic knowledge. In brief, I argue that we should regard our armchair intuitions as providing an important, a priori source of evidence for hypotheses about the contents of our implicit referential policies with regard to our terms. But all such hypotheses have a potential falsifier that is only discoverable empirically. In other words, gold-standard evidence for such hypotheses is always empirical. (shrink)

Thought experiments are employed for a number of reasons and in many different disciplines. This paper explores the work of Novalis in relation to the method of thought experiments in theology, with a special focus on the encounter between Christianity and the science of his day. In a first step I revisit the ongoing philosophical discussion on thought experiments in order to highlight the lack of interest in the literary features of thought experiments. Step two is dedicated to a discussion (...) of the work of Novalis as far as his metaphysics of phantasy and imagination is concerned as it plays out in his romantic poetry. Building on the results of this discussion, in a third step I discuss the relationship (a) between thought experiments in theology and other disciplines, (b) between current discussions of thought experiments and previous periods of philosophical investigation into the ‘laboratory of the mind’, (c) between Christianity and science, and (d) between literary fiction and cognition. (shrink)

Thought experiments play an important cognitive role in many fields of inquiry, especially in physics and philosophy. Do they also matter in revealed theology? In addressing this question, I will argue first why it is important to do so, then elaborate on the characteristic features of such thought experiments in revealed theology, and finally discuss two instances of thought experimenting in Augustine.

The ontological argument is one of the most intriguing lines of reasoning in Western thought. Leaving behind debates over the proper relation between science and religion, it makes a simple move from conceptual analysis to existence in order to prove the existence of god. The ontological argument will be reviewed against the background of the contemporary debate on thought experiments. Assuming that the ontological argument fails as a philosophical proof, I will argue that its move from concept to existence might (...) best be understood as a thought experiment of revealed theology (a theology based on revelation – unlike philosophical theology/natural theology). Viewed from this perspective it makes sense that Anselm of Canterbury offered his versions of the ontological argument in the form of a prayer, which, presupposing the existence of god, seems to run counter to a proof of god's existence. (shrink)

Suppose that you had always had a physical twin, Chris, who on a different planet went through life having physical characteristics, sensory experiences, utterances, and brain processes exactly the same as yours in every physical and sensory respect. Chris.

It is a commonplace that contemplation of an imaginary particular may have cognitive and motivational effects that differ from those evoked by an abstract description of an otherwise similar state of affairs. In his Treatise on Human Nature, Hume ([1739] 1978) writes forcefully of this.

Contemplating imaginary scenarios that evoke certain sorts of quasi‐sensory intuitions may bring us to new beliefs about contingent features of the natural world. These beliefs may be produced quasi‐observationally; the presence of a mental image may play a crucial cognitive role in the formation of the belief in question. And this albeit fallible quasi‐observational belief‐forming mechanism may, in certain contexts, be sufficiently reliable to count as a source of justification. This sheds light on the central puzzle surrounding scientific thought experiment, (...) which is how contemplation of an imaginary scenario can lead to new knowledge about contingent features of the natural world. (shrink)

It is of great use to the sailor to know the length of his line, though he cannot with it fathom all the depths of the ocean. It is well he knows that it is long enough to reach the bottom at such places as are necessary to direct his voyage, and caution him against running upon shoals that may ruin him.

By carefully examining one of the most famous thought experiments in the history of science—that by which Galileo is said to have refuted the Aristotelian theory that heavier bodies fall faster than lighter ones—I attempt to show that thought experiments play a distinctive role in scientific inquiry. Reasoning about particular entities within the context of an imaginary scenario can lead to rationally justified concluusions that—given the same initial information—would not be rationally justifiable on the basis of a straightforward argument.

The capacity to represent things to ourselves as possible plays a crucial role both in everyday thinking and in philosophical reasoning; this volume offers much-needed philosophical illumination of conceivability, possibility, and the relations between them.

To what extent and how is conceivability a guide to possibility? This essay explores general philosophical issues raised by this question, and critically surveys responses to it by Descartes, Hume, Kripke and "two-dimensionalists.".

Kripkean examples of necessary a posteriori truths clearly provide a challenge to attempts to connect facts about possibility to facts about what people can conceive. The paper argues for a general principle connecting imaginability under certain special circumstances to possibility; it also discusses some of the issues raised by the resulting position.

Part I : how does that go? : the limits of philosophical argument -- Quine's "Two dogmas" : argument or imagination? -- Argument and intuition in Kripke's Naming and necessity -- The rise and fall of counterexamples : Gettier, Goldman, and Lewis -- Reflection : pictures, intuitions, and philosophical knowledge -- Part II : arguments and convictions -- Turning the tables : Plantinga and the rise of philosophy of religion -- Materialism and compatibilism : two dogmas of analytic philosophy? -- (...) Was there a Kuhnian revolution? : convictions in the philosophy of science -- Conviction and argument in Rawls' A theory of justice -- Part III : philosophical truth and knowledge -- Rorty against the world : philosophy, truth, and objectivity -- Philosophical knowledge : conclusions and an application. (shrink)

Recent debates about thought experiments have focused on a perceived epistemological problem: how do thought experiments manage to provide knowledge when they yield no new empirical data? A bold answer to this question is provided by James Robert Brown’s platonisrn, according to which a certain class of thought experiments allow a sort of intellectual perception of laws of nature, understood as relations between universals. I suggest that there are three main problems with platonism. First, it is restricted to a very (...) small class of thought experiments; hence, it largely fails to address the general epistemological problem. Second, it is not quite clear what it is supposed to explain. Third, its explanatory value in any case seems dubious, since the mechanisms it postulates (i) appear to raise issues more ditficult than what they would explain, and (ii) seem to obviate the very need for conducting thought experiments. I also argue that it fails to give an accurate account of Brown’s flagship example, Galileo’s thought experiment on falling bodies. In conclusion, I suggest that although platonism about thought experiments is an exciting thesis, it is at present unconvincing. (shrink)

Keith DeRose has argued that context shifting experiments should be designed in a specific way in order to accommodate what he calls a ‘truth/falsity asymmetry’. I explain and critique DeRose's reasons for proposing this modification to contextualist methodology, drawing on recent experimental studies of DeRose's bank cases as well as experimental findings about the verification of affirmative and negative statements. While DeRose's arguments for his particular modification to contextualist methodology fail, the lesson of his proposal is that there is good (...) reason to pay close attention to several subtle aspects of the design of context shifting experiments. (shrink)

Recently, a new movement of philosophers, called 'experimental philosophy', has suggested that the philosophers' favored armchair is in flames. In order to assess some of their claims, it is helpful to provide a theoretical background against which we can discuss whether certain facts are, or could be, evidence for or against a certain view about how philosophical intuitions work and how good they are. In this paper, I will be mostly concerned with providing such a theoretical background, and I will (...) start discussing in which way experimental philosophy challenges the reliability of philosophical intuitions and how its challenge fits into some more theoretical considerations that also point towards a reliability problem for intuitions. The paper attempts to argue that a certain account of intuitions—the imaginationist account—is available which is well-suited for explicating the expertise reply to the challenge of experimental philosophy. (shrink)

Preface: This volume originated in a conference on "The Place of Thought Experiments in Science and Philosophy" which was organized by us and held at the Center for Philosophy of Science at the University of Pittsburgh, April 18-20, 1986. The idea behind this conference was to encourage philosophers and scientists to talk to each other about the role of thought experiments in their various disciplines. These papers were either written for the conference, or were written after it by commentators and (...) other participants.... We hope that this volume will be of use to other philosophers and scientists who are interested in thought experiments, as well as inspire more work in this area. (shrink)

In this paper, I am going to offer a reconstruction of a challenge to intuition-based armchair philosophy that has been put forward by experimental philosophers of a restrictionist stripe, which I will call the 'master argument'. I will then discuss a number of popular objections to this argument and explain why they either fail to cast doubt on its first, empirical premise or do not go deep enough to make for a lasting rebuttal. Next, I will consider two more promising (...) objections, the grounding objection and the expertise objection, which aim at the second, epistemic premise of the argument. Against this background, I will then suggest what I call 'conservative restrictionism' as the most reasonable default reaction to the experimentalist challenge, which is a combination of the two views of local restrictionism and methodological conservativism. (shrink)

Experimental philosophy is one of the most recent and controversial developments in philosophy. Its basic idea is rather simple: to test philosophical thought experiments and philosophers’ intuitions about them with scientific methods, mostly taken from psychology and the social sciences. The ensuing experimental results, such as the cultural relativity of certain philosophical intuitions, has engaged – and at times infuriated – many more traditionally minded "armchair" philosophers since then. In this volume, the metaphilosophical reflection on experimental philosophy is brought yet (...) another step forward by engaging some of its most renowned proponents and critics in a lively and controversial debate. In addition to that, the volume also contains original experimental research on personal identity and philosophical temperament, as well as state-of-the-art essays on central metaphilosophical issues, like thought experiments, the nature of intuitions, or the status of philosophical expertise. -/- This book was originally published as a special issue of Philosophical Psychology. (shrink)

In this brief introduction, we would first like to explain how these two special issues of Philosophical Psychology ( 23.3 and 23.4 ) actually came about. In addition, we will provide an outline of their overall structure and shortly summarize the featured papers.

I criticize Timothy Williamson's characterization of thought experiments on which the central judgments are judgments of contingent counterfactuals. The fragility of these counterfactuals makes them too easily false, and too difficult to know.

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)

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.

The scales across which physical properties exist are vast and subtle in their effects on particular systems placed locally on such scales. For example, human experiential access is restricted only to partial segments of the mass density, size, and temperature scales of the universe. I argue that philosophers must learn to appreciate better the effects of physical scales. Specifically, thought experiments in philosophy should be more sensitive to physical scale effects, because the conclusion of a thought experiment may be undermined (...) by unintentionally ignored scale effects, and the changes required to obtain the foreground state of affairs in a thought experiment might require unacknowledged scale-spanning changes to the contextual background. I discuss four philosophical thought experiments: Putnam's Twin Earth and Brain in a Vat, Searle's Chinese Room, and Chalmers's Zombies Without Qualia. I close by briefly defending the greater interest and importance of physical possibility over logical possibility. (shrink)

The main concern of this paper is to show that understanding mental variation may prove to be relevant to inquiry into thought experiments. First, I examine why Ernst Mach considered the ability to vary the contents of one's thoughts the principal requirement for thought experimentation. Second, I illustrate the wide applicability of mental variation in thought experiments. Third, I suggest, following Kathleen Wilkes, that variation is frequently employed in “realistic” thought experiments.

Since there isn't a computer that seems conscious at this time, the idea of machine consciousness is supported by thought experiments. Here's one old chestnut: "What if you replaced your neurons one by one with neuron sized and shaped substitutes made of silicon chips that perfectly mimicked the chemical and electric functions of the originals? If you just replaced one single neuron, surely you'd feel the same. As you proceed, as more and more neurons are replaced, you'd stay conscious. Why (...) wouldn't you still be conscious at the end of the process, when you'd reside in a brain shaped glob of silicon? And why couldn't the resulting replacement brain have been manufactured by some other means?". (shrink)

From Descartes to designer babies, The Philosophy Gym poses questions about some of history's most important philosophical issues, ranging in difficulty from pretty easy to very challenging. He brings new perspectives to age-old conundrums while also tackling modern-day dilemmas -- some for the first time. Begin your warm up by contemplating whether a pickled sheep can truly be considered art, or dive right in and tackle the existence of God. In this radically new way of looking at philosophy, Stephen Law (...) illustrates the problem with a story, then lets the argument battle it out in clear, easily digestible and intelligent prose. This perfect little mental health club is sure to give each reader's mind a great workout. (shrink)

There has been a movement recently to bring to bear on the conduct of philosophical thought experiments (henceforth “thought experiments”)1 the empirical techniques of the social sciences, that is, to treat their conduct as in the nature of an anthropological investigation into the application conditions of the concepts of a group of subjects. This is to take a third person, in contrast to the traditional first person, approach to conceptual analysis. This has taken the form of conducting surveys about scenarios (...) used in thought experiments.2 It has been called “experimental philosophy” by its practitioners and has been applied across a range of fields: the philosophy of language, the philosophy of action, the philosophy of mind, epistemology, and ethics.3 The results of these surveys have been used to support conclusions about the application conditions of particular concepts of interest in philosophy. They have also been used to support (and been motivated by) skeptical claims about the traditional approach to conceptual analysis. The.. (shrink)

Abstract: 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.

Roy Sorensen advances an evolutionary explanation of our capacity for thought experiments which doubles as a naturalized epistemological justification. I argue Sorensens explanation fails to satisfy key elements of environmental-selectionist explanations and so fails to carry epistemic force. I then argue that even if Sorensen succeeds in showing the adaptive utility of our capacity, he still fails to establish its reliability and hence epistemic utility. I conclude Sorensens account comes to little more than a just-so story.

It is commonly held that our intuitive judgements about imaginary problem cases are justified a priori, if and when they are justified at all. In this paper I defend this view — ‘rationalism’ — against a recent objection by Timothy Williamson. I argue that his objection fails on multiple grounds, but the reasons why it fails are instructive. Williamson argues from a claim about the semantics of intuitive judgements, to a claim about their psychological underpinnings, to the denial of rationalism. (...) I argue that the psychological claim — that a capacity for mental simulation explains our intuitive judgements — does not, even if true, provide reasons to reject rationalism. (More generally, a simulation hypothesis, about any category of judgements, is very limited in its epistemological implications: it is pitched at a level of explanation that is insensitive to central epistemic distinctions.) I also argue that Williamson’s semantic claim — that intuitive judgements are judgements of counterfactuals — is mistaken; rather, I propose, they are a certain kind of metaphysical possibility judgement. Several other competing proposals are also examined and criticized. (shrink)

When they abandoned the analytic-synthetic distinction, analytic philosophers substituted for it uncritical appeals to thought experiments or conceivability arguments. Although the history of philosophy is replete with thought experiments, medieval and early modern philosophers developed sophisticated theories concerning what governs what happens in thought experiments. By contrast, contemporary philosophers subscribe to the thesis of facile conception according to which casual allegations of conceivability or inconceivability are taken as good evidence of possibility or impossibility. Philosophers need to adopt standards of thought (...) experimentation like those found in science and to ground them in a general theory of conceivability. (shrink)

Thought experiment acquires evidential significance only on particular metaphysical assumptions. These include the thesis that science aims at uncovering "phenomena"universal and stable modes in which the world is articulatedand the thesis that phenomena are revealed imperfectly in actual occurrences. Only on these Platonically inspired assumptions does it make sense to bypass experience of actual occurrences and perform thought experiments. These assumptions are taken to hold in classical physics and other disciplines, but not in sciences that emphasize variety and contingency, such (...) as Aristotelian natural philosophy and some forms of historiography. This explains why thought experiments carry weight in the former but not the latter disciplines. (shrink)

Intuitions are funny things. Intuitions would seem to be these fluid, temporary mental states that we form minute by minute. On the face of it, they would seem to have no real value. But, when we ask whether a particular theory is true, we usually turn to our intuitions. This is nowhere more prevalent than in moral theorizing. When we attempt to show that a particular moral theory is mistaken, we usually present cases that yield counterintuitive results for the theory. (...) For example, take the famous Trolley Car example. Suppose a trolley car is traveling down a steep street and is heading straight for a child. Suppose further that you have the means to push a button that will divert the trolley car to a different track thereby missing the child. But, if you push the button to save the one child, you will kill five other children standing on the other track to which the trolley car will be diverted. So the choice is do not push the button and let one child die, or push the button, saving, the one child, but killing five other children. What do you do? Such cases are common in moral theorizing and our intuitions concerning what we would do in such cases are usually taken as evidence for or against a moral theory. In the trolley car case, a utilitarian would say, ceteris paribus, you should not push the button diverting the trolley car. Since an action is morally right if and only if it produces more net good (say, pleasure), diverting the trolley car would result in more pain in the world and hence be the wrong action. But how do our intuitions evidentially fit into the case? Since our goal is to have a moral theory that coincides with our intuitions about cases, if our intuitions fit with the theory, then we have prima facie evidence for the theory. If our intuitions do not fit, then we have prima facie evidence against the theory. Concerning the trolley car case, if our intuitions are that we should not push the button, thus letting the single child die, then our intuitions count as evidence for the correctness of utilitarian moral theory. If we do not share the intuitions of the utilitarians, then it is said to count as evidence against the correctness of utilitarian moral theory. Thus, it is our intuitions that carry the evidential burden. Since most agents take their intuitions to have significant evidential weight, cases (such as the Trolley Car case) usually indicate something problematic with the theory in question. Yet, there has been considerable interest lately in the status of such a practice. This interest has in part surrounded the issue of whether the cases themselves pose a problem for moral theorizing. Such cases are sometimes called intuition pumps. These thought experiment-style cases are usually taken to elicit intuitions that count for or against a moral theory. But many have claimed that the reliance upon such intuition pumps in moral theorizing is unjustified. In this paper I will investigate this claim. First, I lay out what I take to be the problem of intuition pumps. In particular, the problem will surround (1) there always being the possibility of constructing new cases that “pump” people’s intuitions to the other side of a moral debate and (2) there being systematic and patterned disagreement as to what the “correct” intuitive response for a given case is. Next, I give an account of the structure and evidence-conferring status of intuitions. Then, given this account, I illustrate how we can and why we should appeal to the intuitions of experts to solve the problem of intuition pumps. Thus, I hope to show that the problem of intuition pumps is not a problem for moral theorizing. That is, the use of intuition pump-style cases in moral theorizing is prima facie justified. (shrink)

In this paper, I argue that appeals to intuition are strong arguments just in case there is an agreement among the relevant philosophers concerning the intuition in question. Otherwise, appeals to intuition are weak arguments.

An overview is provided of how the concept of the thought experiment has developed and changed for the natural sciences in the course of the 20th century. First, we discuss the existing definitions of the term 'thought experiment' and the origin of the thought experimentation method, identifying it in Greek Presocratics epoch. Second, only in the end of the 19th century showed up the first systematic enquiry on thought experiments by Ernst Mach's work. After the Mach's work, a negative attitude (...) towards thought experiments came in the beginning of the 20th century, which went on until the Thomas Kuhn's and Karl Popper's work on thought experiments. Only from the mid-1980s did thought experiments begin to be considered relevant to scientific enterprise. Finally, we show the existing empirical and 'functional' theories which have developed about the nature and purpose of thought experiments. (shrink)

Canadian Journal of Philosophy, 26, pp. 333-66. 1996.

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)

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.

A characteristic of contemporary analytic philosophy is its ample use of thought experiments. We formulate two features that can lead one to suspect that a given thought experiment is a poor one. Although these features are especially in evidence within the philosophy of mind, they can, surprisingly enough, also be discerned in some celebrated scientific thought experiments. Yet in the latter case the consequences appear to be less disastrous. We conclude that the use of thought experiments is more successful in (...) science than in philosophy. (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)

This entry addresses the nature and epistemological role of intuition by considering the following questions: (1) What are intuitions?, (2) What roles do they serve in philosophical (and other “armchair”) inquiry?, (3) Ought they serve such roles?, (4) What are the implications of the empirical investigation of intuitions for their proper roles?, and (5) What is the content of intuitions prompted by the consideration of hypothetical cases?