Popular two-factor accounts of thought insertion hold that this symptom of psychosis is caused by two elements working in tandem: an anomalous experience of some kind (the first factor) and a reasoning deficit or bias (the second factor). This chapter develops a very different alternative to explaining and treating thought insertion—one that views thought insertion as a form persecutory delusion. If this thesis is correct, clinical interventions for persecutory delusions may be successful for thought insertion as (...) well. The chapter begins by presenting several difficulties for two-factor accounts of thought insertion and for two-factor accounts of delusions more generally. It then discusses positive reasons for seeing thought insertion as a form of persecutory delusion. The positive case begins with reflection on first-person descriptions of thought insertion gleaned from online discussion forums. It continues by considering ways in which clinical diagnostic tools may create the appearance of deep differences between symptoms such as thought insertion and persecutory delusions where there are none. This case is bolstered by evidence for considerable variability in the content of delusions patients present with over time. Implications for the treatment of thought insertion are then considered. (shrink)

Recent third person approaches to thought experiments and conceptual analysis through the method of surveys are motivated by and motivate skepticism about the traditional first person method. I argue that such surveys give no good ground for skepticism, that they have some utility, but that they do not represent a fundamentally new way of doing philosophy, that they are liable to considerable methodological difficulties, and that they cannot be substituted for the first person method, since the a priori knowledge (...) which is our object in conceptual analysis can be acquired only from the first person standpoint. (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)

When one thinks—knows, believes, imagines—that something is the case, one’s thought has a topic: it is about something, towards which one’s mind is directed. What is the logic of thought, so understood? This book begins to explore the idea that, to answer the question, we should take topics seriously. It proposes a hyperintensional account of the propositional contents of thought, arguing that these are individuated not only by the set of possible worlds at which they are true, (...) but also by their topic: what they are about. The book then builds epistemic, doxastic, probabilistic, and conditional logics based on this view. It applies them to issues ranging from dogmatism, scepticism, and epistemic fallibilism, to imagination and suppositional reasoning, belief revision, framing effects, and the acceptability of indicative conditionals. (shrink)

Thought experiments play a role in science and in some central parts of contemporary philosophy. They used to play a larger role in philosophy of science, but have been largely abandoned as part of the field’s “practice turn”. This chapter discusses possible roles for thought experimentation within a practice-oriented philosophy of science. Some of these roles are uncontroversial, such as exemplification and aiding discovery. A more controversial role is the reliance on thought experiments to justify philosophical claims. (...) It is proposed that if we adopt an underlying empiricist view of concepts, then thought experiments can be seen as affording us contact with scientific practice, despite their seemingly a priori character. The advantages and drawbacks of thought experiments are discussed via comparison with case studies, on the one, and simulations on the other hand. The chapter closes with some remarks on how to combine thought experiments with other methods. (shrink)

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)

Our understanding of what exactly needs protected against in order to safeguard a plausible construal of our ‘freedom of thought’ is changing. And this is because the recent influx of cognitive offloading and outsourcing—and the fast-evolving technologies that enable this—generate radical new possibilities for freedom-of-thought violating thought manipulation. This paper does three main things. First, I briefly overview how recent thinking in the philosophy of mind and cognitive science recognises—contrary to traditional Cartesian ‘internalist’ assumptions—ways in which our (...) cognitive faculties, and even our beliefs, can be materially realised by as well as stored non-biologically and extracranially. Second, and taking brain-computer interface technologies (BCIs) and the associated possibility of ‘extended’ beliefs as a reference point, I propose and defend a sufficient condition on freedom-of-thought violating (extended) thought manipulation. On the view proposed, the right not to have one’s thoughts or opinions manipulated is violated if one is (i) caused to acquire non-autonomous propositional attitudes (acquisition manipulation) or (ii) caused to have otherwise autonomous propositional attitudes non-autonomously eradicated (eradication manipulation). The implications of this view are then illustrated through four thought experiments, which map on to four distinct ways—what I call Type 1-Type 4 manipulation—in which, and with reference to the view defended, one’s freedom of thought is plausibly violated. (shrink)

Inspired by Castañeda (1966, 1968), Perry (1979) and Lewis (1979) showed that a specific variety of singular thoughts, thoughts about oneself “as oneself” – de se thoughts, as Lewis called them – raise special issues, and they advanced rival accounts. Their suggestive examples raise the problem of de se thought – to wit, how to characterize it so as to give an accurate account of the data, tracing its relations to singular thoughts in general. After rehearsing the main tenets (...) of two contrasting accounts – a Lewisian one and a Perrian one – in the first section of this paper, in the second I will present a proposal of my own, which is a specific elaboration of the Perrian account. In the first section I will indicate some weaknesses of Perry’s presentation of his view; the proposal I will articulate in the second overcomes them. I will conclude with a brief discussion of reasons for preferring one or another account, in particular regarding the issue of the communication of de se thoughts. (shrink)

This work investigates intuitions' nature, demonstrating how philosophers can best use them in epistemology. First, the author considers several paradigmatic thought experiments in epistemology that depict the appeal to intuition. He then argues that the nature of thought experiment-generated intuitions is not best explained by an a priori Platonism. Second, the book instead develops and argues for a thin conception of epistemic intuitions. The account maintains that intuition is neither a priori nor a posteriori but multi-dimensional. It is (...) an intentional but non-propositional mental state that is also non-conceptual and non-phenomenal in nature. Moreover, this state is individuated by its progenitor, namely, the relevant thought experiment. Third, the author provides an argument for the evidential status of intuitions based on the correct account of the nature of epistemic intuition. The suggestion is the fitting-ness approach: intuition alone has no epistemic status. Rather, intuition has evidentiary value as long as it fits well with other pieces into a whole, namely, the pertinent thought experiment. Finally, the book addresses the key challenges raised by supporters of anti-centrality, according to which philosophers do not regard intuition as central evidence in philosophy. To that end, the author responds to them, showing that they fail to affect the account of intuition developed in this book. This text appeals to students and researchers working in epistemology. (shrink)

To a large extent, the evidential base of claims in the philosophy of science has switched from thought experiments to case studies. We argue that abandoning thought experiments was a wrong turn, since they can effectively complement case studies. We make our argument via an analogy with the relationship between experiments and observations within science. Just as experiments and ‘natural’ observations can together evidence claims in science, each mitigating the downsides of the other, so too can thought (...) experiments and case studies be mutually supporting. After presenting the main argument, we look at potential concerns about thought experiments, suggesting that a judiciously applied mixed-methods approach can overcome them. (shrink)

In my dissertation, I develop a novel approach to thought experiments and literary learning. It’s novel primarily because, unlike many prominent approaches, it has us refrain from advancing theories, from giving logical analyses, and from explicating. We are, instead, to proceed in a way inspired by Wittgenstein’s writings. We are, that is, to clarify words that give rise to problems and to clear those problems away. To clarify words, we may compare language games in which figure terms like “ (...) class='Hi'>thought experiment.” Thereby, we might see that the concept these terms express has a family resemblance character. To clear away problems, we may describe how such a concept, if not illuminated, yields philosophical problems about thought experiments and literary learning. -/- After I develop this approach, I bring it to bear on two problems, and I achieve two main results. One problem concerns the nature of thought experiments. It is: Why do we have trouble explaining what we know them to be? I find that, despite appearances, we have no such trouble. Central to this result are two claims about thought experiments. One is that imaginings aren’t common to them. The other is that our unreflective concept of them has a family resemblance character. -/- The other problem concerns stories in works of literary fiction. It is: How could we possibly learn about the world from them? To solve it, you might claim that we learn by performing thought experiments, and then appeal to a theory of them. I find that you’d risk explaining the wrong thing. That is, you may well explain only how we learn—not how we do so from literature itself. Central to this result are three claims, which concern how these stories differ from thought experiments. They differ, I claim, (i) in how we count imaginings as experiences of them, (ii) in how free we are to interpret them, and (iii) in how complex they may be. This done, I’ve twice taken my novel approach and achieved results. (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)

A singular thought can be characterized as a thought which is directed at just one object. The term ‘thought’ can apply to episodes of thinking, or to the content of the episode (what is thought). This paper argues that episodes of thinking can be just as singular, in the above sense, when they are directed at things that do not exist as when they are directed at things that do exist. In this sense, then, singular thoughts (...) are not object-dependent. (shrink)

The Quality of Thought develops and defends the thesis that thinking is a kind of experience, characterized by a sui generis (“cognitive”) phenomenology, determinates of which are thought contents—what I call the phenomenal intentionality of thought thesis. It draws out the implications of this thesis for issues in philosophy of mind, philosophy of language and metaphysics. The view defended is radically internalist and intensionalist, and thus goes against received doctrines in philosophy of mind (externalism) and language (extensionalism). (...) It also advocates for a metaphysically neutral, non-naturalistic approach to the philosophical study of mind—what I call “Analytic Phenomenology”—in combination with agnosticism about the nature of the relationship between consciousness and physical reality. -/- The book identifies persistent problems with Dretske-inspired causal-informational-teleological theories of conceptual content, and diagnoses them as due to leaving out what it’s like to think a thought—to entertain or grasp a propositional (conceptual) content. It is thus a contribution to the increasingly influential Phenomenal Intentionality Research Program. It includes refutations of classic externalism (Putnam and Burge) and arguments that standard motivations for direct reference theories of names (Kripke), indexicals and demonstratives (Kaplan) are not inevitable, and alternative accounts of their (and their conceptual equivalents’) semantics. It also addresses outstanding challenges to the phenomenal intentionalist view of thought content, including the existence of unconscious thought, the elusiveness of conceptual phenomenology, the matching content problem, phenomenal compositionality, and the determination of conceptual reference. (shrink)

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

Does the capacity to think require the capacity to sense? A lively debate on this topic runs throughout the history of philosophy and now animates discussions of artificial intelligence. Many have argued that AI systems such as large language models cannot think and understand if they lack sensory grounding. I argue that thought does not require sensory grounding: there can be pure thinkers who can think without any sensory capacities. As a result, the absence of sensory grounding does not (...) entail that large language models cannot think or understand. I also consider to what extent quasi-sensory grounding can at least boost the performance of a language model. (shrink)

Thought experiments figure prominently in contemporary epistemology. Beyond that humdrum observation, controversy abounds. The aim of this paper is to make progress on two fronts. On the descriptive front, the aim is to illuminate what the practice of using thought experiments involves. On the normative front, the aim is to illuminate what the practice of using thought experiments should involve. Thought experiments result in judgments that are passed on to further philosophical reasoning. What are these judgments? (...) What is the point of making them? What basis do we have for making them? A conception of thought experiments includes answers to these three questions. My thesis is that epistemologists should use thought experiments in accordance with a conception of them organized around the idea of explanation. My case for endorsing the thesis rests on the fruitfulness of the interventions in current debates about the content, point, and basis of thought experiment judgments that it suggests. (shrink)

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)

‘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)

This paper defends a version of the old empiricist claim that to think about unobservable physical properties a subject must be able to think perception-based thoughts about observable properties. The central argument builds upon foundations laid down by G. E. M. Anscombe and P. F. Strawson. It bridges the gap separating these foundations and the target claim by exploiting a neglected connection between thought about properties and our grasp of causation. This way of bridging the gap promises to introduce (...) substantive constraints on right accounts of perception and perception-based thought. (shrink)

This challenging paper presents an ingenious argument for a functionalist theory of mind. Part of the argument: My visual cortex at the back of my brain processes the stimulation to my eyes and then causes other parts of the brain - like the speech centre and the areas involved in thought and movement - to be properly responsive to vision. According to functionalism the whole mental character of vision - the whole of how things look - is fixed purely (...) in the pattern of responses to vision and not in any of the initial processing of vision in the visual cortex. That this functionalist theory of vision is true can be proved with alarming ease. Imagine that just the left side of my visual cortex is replaced by a gadget that has precisely the same input/output relationship to the rest of the brain as the left visual cortex had. According to any view but functionalism, the character of my vision on the right side of my visual field (normally processed by the left visual cortex) would change radically with this change in all the intrinsic properties involved in the visual cortex, with this preservation of nothing but its functional role in bringing about my responses to vision. But, say I, we have enough here to be sure that in such a case there could be no change in the character of my vision. For we know by the stipulation of sameness of output that my responses in speech, thought and movement to the right side of my visual field will be precisely the same as they would have been with the natural left visual cortex and will harmonise just as they would have done with my responses to the other side of my vision. But if half my vision had disappeared or changed I’d be speaking, thinking and acting like someone with problems on the right side of his vision. It is impossible to separate my responses to vision from the character of my vision. The character of my vision is logically determined by the pattern of responses - by nothing but the functional role of my vision. (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 (...) class='Hi'>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)

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)

At first glance there seem to be many similarities between Thomas S. Kuhn’s and Ludwik Fleck’s accounts of the development of scientific knowledge. Notably, both pay attention to the role played by the scientific community in the development of scientific knowledge. But putting first impressions aside, one can criticise some philosophers for being too hasty in their attempt to find supposed similarities in the works of the two men. Having acknowledged that Fleck anticipated some of Kuhn’s later theses, there seems (...) to be a temptation in more recent research to equate both theories in important respects. Because of this approach, one has to deal with the problem of comparing the most notable technical terms of both philosophers, namely ‘‘thought style’’ and ‘‘paradigm’’. This paper aims at a more thorough comparison between Ludwik Fleck’s concept of thought style and Thomas Kuhn’s concept of paradigm. Although some philosophers suggest that these two concepts are essentially equal in content, a closer examination reveals that this is not the case. This thesis of inequality will be defended in detail, also taking into account some of the alleged similarities which may be responsible for losing sight of the differences between these theories. (shrink)

In his book The Things We Mean, Stephen Schiffer advances a subtle defence of what he calls the ‘face-value’ analysis of attributions of belief and reports of speech. Under this analysis, ‘Harold believes that there is life on Venus’ expresses a relation between Harold and a certain abstract object, the proposition that there is life on Venus. The present essay first proposes an improvement to Schiffer’s ‘pleonastic’ theory of propositions. It then challenges the face-value analysis. There will be such things (...) as propositions only if they possess conditions of identity and distinctness. By analyzing Frege’s theory of propositions (Gedanken), I argue that such conditions may be found for the special case of beliefs and sayings advanced as premises and conclusions of deductive arguments. These conditions, however, are not applicable to most ordinary beliefs and sayings. Ordinary attributions and reports, then, do not place thinkers and speakers in relations to propositions. A bonus is exposure of the fallacy in the Putnam-Taschek objection to Frege’s theory of sense and reference. (shrink)

Influential work on proper names, most centrally associated with Kripke (1980), has had a significant influence in the literature on singular thought. The dominant position among contemporary singularists is that we can think singular thoughts about any object we can refer to by name and that, given the range of cases in which it is possible to refer using a name, name use in fact enables singular thought about a name's referent. I call this the extended name-based (...) class='Hi'>thought thesis (extended-NBT). This chapter outlines the reasoning and presumptions of theorists who adopt extended NBT, and also outlines a set of reasons to resist it. The piece is distinctive in approaching the question of the relation between names and singular thought by focusing on the function of names and what this function entails (or doesn’t) about the kinds of thoughts (singular or descriptive) we have when we use names to communicate. In short, thinking about the function of names tells against the claim that name-use enables singular thought. (shrink)

In this paper I aim to illuminate the significance of thought insertion for debates about the first-person concept. My starting point is the often-voiced contention that thought insertion might challenge the thesis that introspection-based self-ascriptions of psychological properties are immune to error through misidentification relative to the first-person concept. In the first part of the paper I explain what a thought insertion-based counterexample to this immunity thesis should be like. I then argue that various thought insertion-involving (...) scenarios do not give rise to successful counterexamples to the immunity of the target class of self-ascriptions. In the second part of the paper I turn to defend a Metasemantic Explanation of why the immunity thesis holds. The Metasemantic Explanation rests on a reference-fixing story about the mental ‘I’ whose key contention is that introspective impressions play an essential role in fixing its reference. It is part of my argument in favour of the proposed reference-fixing story, as well as of the Metasemantic Explanation, that they respect the paradigmatic features of self-ascriptions of inserted thoughts. (shrink)

In his account of the Persian Wars, the 5th century historian Herodotus reports an exchange between the Persian monarch Xerxes and a deposed Spartan king, Demaratus, who became what Lattimore later classified as a “tragic warner” to Xerxes. On the eve of the battle of Thermopylae, Xerxes asks how a small number of free Spartiates can stand up against the massive ranks of soldiers that Xerxes has assembled. Herodotus has Demaratus reply: So is it with the Lacedaemonians; fighting singly they (...) are as brave as any man living, and together they are the best warriors on earth. Free they are, yet not wholly free; for law is their master (ἐλεύθεροι γὰρ ἐόντες οὐ πάντα ἐλεύθεροι εἰσί· ἔπεστι γάρ σφι δεσπότης νόμος), whom they fear much more than your men fear you. This is my proof—what their law bids them, that they do; and its bidding is ever the same, that they must never flee from the battle before whatsoever odds, but abide at their post and there conquer or die. (Hdt. 7.104) As the outcome of Thermopylae makes clear, Demaratus is hardly guilty of boasting. But Greek political theorists were not only fascinated by the Spartans who fought at the battle of Thermopylae in 480; they also wondered how slightly more than a century later Sparta was ignobly defeated by Thebes at the battle of Leuctra in 371, after which Spartan hegemony collapsed. How did Sparta field citizen-soldiers in the 5th century who were without parallel in their bravery and military prowess? And why did Sparta, predominantly under the same political organization, collapse just over a century later? Such are the main questions that Xenophon, Plato, Aristotle, and Plutarch—what Cartledge (1999, 313–14) has characterized as “political-theoretical” laconophiles—seek to answer in their writings about Sparta. (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)

In this paper, I offer reasons for thinking that two prominent sceptical arguments in the literature – the underdetermination-based sceptical argument and the closure-based sceptical argument – are less philosophically interesting than is commonly supposed. The underdetermination-based argument begs the question against a non-sceptic and can be dismissed with little fanfare. The closure-based argument, though perhaps not question-begging per se, does rest upon contentious assumptions that a non-sceptic is under no pressure to accept.

In the modern period, the most original and influential theories about law and politics were developed in connection with a set of far-reaching, interrelated questions about the definition of law, the purpose of law, the relationship between law and morality, and the existence of natural law and natural rights. In this entry I summarize the contributions of Charles-Louis de Secondat, Baron de La Brède et de Montesquieu; William Blackstone; Jeremy Bentham; and Immanuel Kant as exemplars of the history of modern (...) thought on law and politics. (shrink)

In contemporary philosophy of mind and psychiatry, schizophrenic thought insertion is often used as a validating or invalidating counterexample in various theories about how we experience ourselves. Recent work has taken cases of thought insertion to provide an invalidating counterexample to the Humean denial of self-experience, arguing that deficiencies of agency in thought insertion suggest that we normally experience ourselves as the agent of our thoughts. In this paper, I argue that appealing to a breakdown in the (...) sense of agency to explain thought insertion is problematic, and that rather than following the prevailing binary approach which holds that certain features of consciousness go missing while others remain wholly intact, a better explanation involves construing thought insertion as a disturbing or disrupting of the subjectivity (for-me-ness) of experience. The result is that experiencing ourselves as the subject of our thoughts is where future research should be directed, given the robust persistence of this form of self-experience across psychopathological and non-psychopathological cases alike. (shrink)

It is widely supposed that if there is to be a plausible connection between the truth of a de re attitude report about a subject and that subject’s possession of a singular thought, then ‘acquaintance’-style requirements on singular thought must be rejected. I show that this belief rests on poorly motivated claims about how we talk about the attitudes. I offer a framework for propositional attitude reports which provides both attractive solutions to recalcitrant puzzle cases and the key (...) to preserving acquaintance constraints. The upshot is that there is an independently motivated response to the principal argument against acquaintance. (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)

In this paper, I investigate in detail one theoretical approach to the symptom of thought insertion. This approach suggests that patients are lead to disown certain thoughts they are subjected to because they lack a sense of active participation in the occurrence of those thoughts. I examine one reading of this claim, according to which the patients’ anomalous experiences arise from a breakdown of cognitive mechanisms tracking the production of occurrent thoughts, before sketching an alternative reading, according to which (...) their experiences have to be explained in terms of a withdrawal, on the part of the patients themselves, from certain forms of active engagement in reasoning. I conclude with a discussion of the relationship between this view and the idea that patients’ reports of thought insertion reflect a situation in which the boundaries between the self and the world have become uncertain. (shrink)

What would happen if lightning struck a tree in a swamp and transformed it into The Swampman, or if saving billions of lives required sacrificing millions first? The first is a philosophical thought experiment devised by Donald Davidson, the second a theme from a comic written by Alan Moore. I argue that that comics can be read as containing thought experiments and that such philosophical devises should be shared with students of all ages.

(1) Content properties are nonrelational, that is, having a content property does not entail the existence of any contingent object not identical with the thinker or a part of the thinker.2 (2) We have noninferential knowledge of our conscious thoughts, that is, for any of our..

As research on mind wandering has accelerated, the construct’s defining features have expanded and researchers have begun to examine different dimensions of mind wandering. Recently, Christoff and colleagues have argued for the importance of investigating a hitherto neglected variety of mind wandering: “unconstrained thought,” or, thought that is relatively unguided by executive-control processes. To date, with only a handful of studies investigating unconstrained thought, little is known about this intriguing type of mind wandering. Across two experiments, we (...) examined, for the first time, whether changes in task demand influence rates of constrained versus unconstrained thoughts. In both experiments, participants completed either an easy (0-back) or hard (2-back) task and responded to intermittently presented thought probes that gauged thought constraint throughout the task. In Experiment 1, we found that participants completing the easy task engaged in unconstrained thoughts more frequently than those completing the difficult task. In Experiment 2, we replicated this result and further demonstrated manipulations of unconstrained thought while also measuring task-relatedness (a common dimension of mind wandering). Finally, exploratory analyses showed associations between constrained thought and age, verbal intelligence, and an assessment of flow (‘deep effortless concentration’), thereby adding further evidence to indicate a dissociation between task-relatedness and constraint. We discuss the methodological and theoretical applications of our findings to the burgeoning field of research on unconstrained thought. (shrink)

There are a number of conflicting accounts of thought insertion, the delusion that the thoughts of another are inserted into one’s own mind. These accounts share the common assumption of realism: that the subject of thought insertion has a thought corresponding to the description of her thought insertion episode. I challenge the assumption by arguing for an anti-realist treatment of first-person reports of thought insertion. I then offer an alternative account, simulationism, according to which sufferers (...) merely simulate having a thought inserted into their heads. By rejecting realism, the paper undermines a widespread explanatory framework that unites otherwise competing cognitive models of thought insertion. (shrink)

Although formal thought disorder (FTD) has been for long a clinical label in the assessment of some psychiatric disorders, in particular of schizophrenia, it remains a source of controversy, mostly because it is hard to say what exactly the “formal” in FTD refers to. We see anomalous processing of terminological knowledge, a core construct of human knowledge in general, behind FTD symptoms and we approach this anomaly from a strictly formal perspective. More specifically, we present here a symbolic computational (...) model of storage in, and activation of, a human semantic network, or semantic memory, whose core element is logical form; this is normalized by description logic (DL), namely by CL, a DL-based language – Conception Language – designed to formalize conceptualization from the viewpoint of individual cognitive agency. In this model, disruptions in the rule-based implementation of the logical form account for the apparently semantic anomalies symptomatic of FTD, which are detected by means of a CL-based algorithmic assessment. (shrink)

Various psychopathologies of self-awareness, such as somatoparaphrenia and thought insertion in schizophrenia, might seem to threaten the viability of the higher-order thought (HOT) theory of consciousness since it requires a HOT about one’s own mental state to accompany every conscious state. The HOT theory of consciousness says that what makes a mental state a conscious mental state is that there is a HOT to the effect that “I am in mental state M” (Rosenthal 2005, Gennaro 2012). In a (...) previous publication (Gennaro 2015), I argued that a HOT theorist can adequately respond to this concern with respect to somatoparaphrenia. Somatoparaphrenia is a “depersonalization disorder” which is characterized by the sense of alienation from parts of one’s body. It is a bizarre type of body delusion where one denies ownership of a limb or an entire side of one’s body. My focus in the chapter, however, is on “inserted thoughts” which is a common symptom of schizophrenia, although it will also be useful to contrast it with somatoparaphrenia. Schizophrenia is a mental disorder which most commonly manifests itself through auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking. Thought insertion is the delusion that some thoughts are not “one’s own” in some sense or are somehow being inserted into one’s mind by someone else. Graham and Stephens (2000), for example, have suggested that thought insertion should be understood as alienated self-consciousness or meta-representation. I argue that HOT theory has nothing to fear from this phenomenon either and can consistently explain what happens in this admittedly unusual case. (shrink)

I argue that Leibniz's rejection of the hypothesis of thinking matter on grounds of unintelligibility conflicts with his position on sensible qualities such as color. In the former case, he argues that thought must be a modification of something immaterial because we cannot explain thought in mechanical terms. In the latter case, however, he (rightly) grants that we cannot explain sensible qualities in mechanical terms, that is, cannot explain why a certain complex mechanical quality gives rise to the (...) appearance of a certain sensible quality, even while insisting that sensible qualities are modifications of bodies. I argue that the two cases are analogous in the relevant respects, and that Leibniz's (plausible) position on sensible qualities should have thrown his Principle of Intelligibility into doubt. (shrink)

Sebastian Rödl portrays much of his work as attempts at articulating a German idealist view of self-consciousness. Although he rarely engages directly with German idealist texts, his accounts of first-person and second-person knowledge arrive at strikingly Fichtean theses regarding the necessary identity of subject and object in the former and the necessary reciprocity of subject and other in the latter. Despite this affinity, I argue, Rödl's accounts lack a feature that is essential to Fichte's and, indeed, to German idealism's distinctive (...) orientation: the thought of a first principle. I show that while second-person knowledge between subjects is genetically prior to self-consciousness—for Fichte as for Rödl—first-person knowledge of the I as first principle is systematically prior to self-consciousness—a point of architectonic and anti-nihilistic importance for Fichte, but which goes missing on Rödl's accounts, thereby obstructing their intended German idealist articulation. (shrink)

Animalism is prima facie the most plausible view about what we are; it aligns better with science and common sense, and is metaphysically more parsimonious. Thought experiments involving the brain, however, tend to elicit intuitions contrary to animalism. In this paper, I examine two classical thought experiments from the literature, brain transplant and cerebrum transplant, and a new one, cerebrum regeneration. I argue that they are theoretically possible, but that a scientifically informed account of what would actually happen (...) shows that in none of the cases would the person be separated from the animal. Our intuitions in these cases, when adequately informed by neuroscience, do not conflict with animalism – rather, they suggest a correction of the animalist position: the persisting animal should be at least minimally sentient. Sentience animalism is a new formulation of the animalist account of personal identity that allows us to reconcile facts about our biological persistence conditions with the intuition that human persistence should involve some kind of psychological continuity. (shrink)

The contents of our conscious mind can seem unpredictable, whimsical, and free from external control. When instructed to attend to a stimulus in a work setting, for example, one might find oneself thinking about household chores. Conscious content thus appears different in nature from reflex action. Under the appropriate conditions, reflexes occur predictably, reliably, and via external control. Despite these intuitions, theorists have proposed that, under certain conditions, conscious content resembles reflexes and arises reliably via external control. We introduce the (...) Reflexive Imagery Task, a paradigm in which, as a function of external control, conscious content is triggered reliably and unintentionally: When instructed to not subvocalize the name of a stimulus object, participants reliably failed to suppress the set-related imagery. This stimulus-elicited content is considered ‘high-level’ content and, in terms of stages of processing, occurs late in the processing stream. We discuss the implications of this paradigm for consciousness research. (shrink)

De re or singular thoughts are, intuitively, those essentially or constitutively about a particular object or objects; any thought about different objects would be a different thought. How should a philosophical articulation or thematization of their nature look like? In spite of extended discussion of the issue since it was brought to the attention of the philosophical community in the late fifties by Quine (1956), we are far from having a plausible response. Discussing the matter in connection with (...) the status of the Kripkean category of the contingent a priori, Donnellan (1979) argued that what can be properly classified as knowable a priori about utterances like those involving ‘one meter’ or ‘Neptune’ famously proposed by Kripke (1980) cannot be the very same singular content that is contingent he distinguished to that end between knowing a true proposition expressed by an utterance, and knowing that an utterance expresses a true proposition. Evans (1979) replied that, for a very specific sort of cases involving “descriptive names”, a related proto-two-dimensionalist account should be preferred, on which it is not the singular contingent content, but rather a general descriptive one which is knowable a priori. In a series of papers, Robin Jeshion (2000, 2001) has recently attacked Donnellan's proposal, arguing in favour of the most straightforward interpretation of Kripke's claim: in the relevant cases, the very same singular content can be both contingent and knowable a priori. This paper appeals to a generalized version of two-dimensional semantics to advance an account of the Kripkean cases along the lines of Evans's, and argues that Jeshion's compelling arguments against Donnellan's view do not apply to this version. (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.

Call a thought whose expression involves the utterance of an indexical an indexical thought. Thus, my thoughts that I’m annoyed, that now is not the right time, that this is not acceptable, are all indexical thoughts. Such thoughts present a prima facie problem for the thesis that thought contents are phenomenally individuated -- i.e., that each distinct thought type has a proprietarily cognitive phenomenology such that its having that phenomenology makes it the thought that it (...) is -- given the assumption that phenomenology is intrinsically determined. My concern in this paper is to blunt standard intuitions concerning the external individuation of indexical thought contents, and to defend a conception of indexical thought content that is entirely phenomenal and internalist. (shrink)