In a 2002 article Stewart Cohen advances the “bootstrapping problem” for what he calls “basic justification theories,” and in a 2010 followup he offers a solution to the problem, exploiting the idea that suppositional reasoning may be used with defeasible as well as with deductive inference rules. To curtail the form of bootstrapping permitted by basic justification theories, Cohen insists that subjects must know their perceptual faculties are reliable before perception can give them knowledge. But how is such (...) knowledge of reliability to be acquired if not through perception itself? Cohen proposes that such knowledge may be acquired a priori through suppositional reasoning. I argue that his strategy runs afoul of a plausible view about how epistemic principles function; in brief, I argue that one must actually satisfy the antecedent of an epistemic principle, not merely suppose that one does, to acquire any justification by its means – even justification for a merely conditional proposition. (shrink)

James Van Cleve raises some objections to my attempt to solve the bootstrapping problem for what I call “basic justification theories.” I argue that given 1 the inference rules endorsed by basic justification theorists, we are a priori (propositionally) justified in believing that perception is reliable. This blocks the bootstrapping result.

Suppositional reasoning can seem spooky. Suppositional reasoners allegedly (e.g.) “extract knowledge from the sheer workings of their own minds” (Rosa), even where the knowledge is synthetic a posteriori. Can literary fiction pull such a rabbit out of its hat? Where P is a work’s fictional ‘premise’, some hold that some works reason declaratively (supposing P, Q), imperatively (supposing P, do Q), or interrogatively (supposing P, Q?), and that this can be a source of knowledge if the (...) class='Hi'>reasoning is good. True, I will argue, although only within the context of judicious critical interpretation. Further evident constraints include that the form of the suppositional reasoning needs to be declarative or imperative, and that the fictional ‘premise’ of the work needs to be a metaphysical counterfactual possibility, not merely a temporal counterfactual and not merely an epistemic possibility or probabilistic supposition. (shrink)

I object to Markos Valaris’s thesis that reasoning requires a belief that your conclusion follows from your premisses. My counter-examples highlight the important but neglected role of suppositional reasoning in the basis of so much of what we know.

Arguments and conditionals are powerful means language provides us to reason about possibilities and to reach conclusions from premises. These two kinds of constructions exhibit several affinities—e.g., they both come in different varieties depending on the mood; they share some of the same connectives (i.e., ‘then’); they allow for similar patterns of modal subordination. In the light of these affinities, it is not surprising that prominent theories of conditionals—old and new suppositionalisms as well as dynamic theories of conditionals—as well as (...) certain reductive theories of arguments tend to semantically assimilate conditionals and arguments. In this paper, I shall marshall some linguistic evidence as well as some theoretical considerations for thinking that, despite these similarities, arguments and conditionals should be given a different semantics and I shall lay out a framework that can capture at least some of their affinities while accounting for their outstanding differences. (shrink)

This paper presents a unifying diagnosis of a number of important problems facing existing models of rational choice under moral uncertainty and proposes a remedy. I argue that the problems of (i) severely limited scope, (ii) intertheoretic comparisons, and (iii) 'swamping’ all stem from the way in which values are assigned to options in decision rules such as Maximisation of Expected Choiceworthiness. By assigning values to options under a given moral theory by asking something like ‘how much do I desire (...) this option, supposing this theory is true?’ rather than ‘how much value does this theory assign to this option?’ these problems can be avoided, while the appealing features of these accounts can be preserved. This amendment provides a role for the preferences, desires, or goals of rational agents that is curiously absent from the existing discussion of what individuals rationally ought to do when they are uncertain about what they morally ought to do. (shrink)

This dissertation is devoted to empirically contrasting the Suppositional Theory of conditionals, which holds that indicative conditionals serve the purpose of engaging in hypothetical thought, and Inferentialism, which holds that indicative conditionals express reason relations. Throughout a series of experiments, probabilistic and truth-conditional variants of Inferentialism are investigated using new stimulus materials, which manipulate previously overlooked relevance conditions. These studies are some of the first published studies to directly investigate the central claims of Inferentialism empirically. In contrast, the (...) class='Hi'>Suppositional Theory of conditionals has an impressive track record through more than a decade of intensive testing. The evidence for the Suppositional Theory encompasses three sources. Firstly, direct investigations of the probability of indicative conditionals, which substantiate “the Equation” (P(if A, then C) = P(C|A)). Secondly, the pattern of results known as “the defective truth table” effect, which corroborates the de Finetti truth table. And thirdly, indirect evidence from the uncertain and-to-if inference task. Through four studies each of these sources of evidence are scrutinized anew under the application of novel stimulus materials that factorially combine all permutations of prior and relevance levels of two conjoined sentences. The results indicate that the Equation only holds under positive relevance (P(C|A) – P(C|¬A) > 0) for indicative conditionals. In the case of irrelevance (P(C|A) – P(C|¬A) = 0), or negative relevance (P(C|A) – P(C|¬A) < 0), the strong relationship between P(if A, then C) and P(C|A) is disrupted. This finding suggests that participants tend to view natural language conditionals as defective under irrelevance and negative relevance (Chapter 2). Furthermore, most of the participants turn out only to be probabilistically coherent above chance levels for the uncertain and-to-if inference in the positive relevance condition, when applying the Equation (Chapter 3). Finally, the results on the truth table task indicate that the de Finetti truth table is at most descriptive for about a third of the participants (Chapter 4). Conversely, strong evidence for a probabilistic implementation of Inferentialism could be obtained from assessments of P(if A, then C) across relevance levels (Chapter 2) and the participants’ performance on the uncertain-and-to-if inference task (Chapter 3). Yet the results from the truth table task suggest that these findings could not be extended to truth-conditional Inferentialism (Chapter 4). On the contrary, strong dissociations could be found between the presence of an effect of the reason relation reading on the probability and acceptability evaluations of indicative conditionals (and connate sentences), and the lack of an effect of the reason relation reading on the truth evaluation of the same sentences. A bird’s eye view on these surprising results is taken in the final chapter and it is discussed which perspectives these results open up for future research. (shrink)

Applying good inductive rules inside the scope of suppositions leads to implausible results. I argue it is a mistake to think that inductive rules of inference behave anything like 'inference rules' in natural deduction systems. And this implies that it isn't always true that good arguments can be run 'off-line' to gain a priori knowledge of conditional conclusions.

Williamson has argued against scepticism concerning our metaphysically modal knowledge, by arguing that standard patterns of suppositional reasoning to counterfactual conclusions provide reliable sources of correct ascriptions of possibility and necessity. The paper argues that, while Williamson’s claims relating to necessity may well be right, he has not provided adequate reasons for thinking that the familiar modes of counterfactual reasoning to which he points generalise to provide a decent route to ascriptions of possibility. The paper also explores (...) another path to ascriptions of possibility that may be extracted from Williamson’s ideas, before briefly considering the general status of counterfactual reasoning in relation to our knowledge of possibilities. (shrink)

In this paper I deal with epistemological issues that stem from the hypothesis that reasoning is not only a means of transmitting knowledge from premise-beliefs to conclusion-beliefs, but also a primary source of knowledge in its own right. The idea is that one can gain new knowledge on the basis of suppositional reasoning. After making some preliminary distinctions, I argue that there are no good reasons to think that purported examples of knowledge grounded on pure reasoning (...) are just examples of premise-based inferences in disguise. Next, I establish what kinds of true propositions can to a first approximation be known on the basis of pure reasoning. Finally, I argue that beliefs that are competently formed on the basis of suppositional reasoning satisfy both externalist and internalist criteria of justification. (shrink)

Our understanding of folk and scientific psychology often informs the law’s conclusions regarding questions about the voluntariness of a defendant’s action. The field of psychology plays a direct role in the law’s conclusions about a defendant’s guilt, innocence, and term of incarceration. However, physical sciences such as neuroscience increasingly deny the intuitions behind psychology. This paper examines contemporary biases against the autonomy of psychology and responds with considerations that cast doubt upon the legitimacy of those biases. The upshot is that (...) if reasonable doubt is established regarding whether psychology’s role in the law should be displaced, then there is room for future work to be done with respect to the truth of psychology’s conclusions about criminal responsibility. (shrink)

An organizing theme of the dissertation is the issue of how to make philosophical theories useful for scientific purposes. An argument for the contention is presented that it doesn’t suffice merely to theoretically motivate one’s theories, and make them compatible with existing data, but that philosophers having this aim should ideally contribute to identifying unique and hard to vary predictions of their theories. This methodological recommendation is applied to the ranking-theoretic approach to conditionals, which emphasizes the epistemic relevance and the (...) expression of reason relations as part of the semantics of the natural language conditional. As a first step, this approach is theoretically motivated in a comparative discussion of other alternatives in psychology of reasoning, like the suppositional theory of conditionals, and novel approaches to the problems of compositionality and accounting for the objective purport of indicative conditionals are presented. In a second step, a formal model is formulated, which allows us to derive quantitative predictions from the ranking-theoretic approach, and it is investigated which novel avenues of empirical research that this model opens up for. Finally, a treatment is given of the problem of logical omniscience as it concerns the issue of whether ranking theory (and other similar approaches) makes too idealized assumptions about rationality to allow for interesting applications in psychology of reasoning. Building on the work of Robert Brandom, a novel solution to this problem is presented, which both opens up for new perspectives in psychology of reasoning and appears to be capable of satisfying a range of constraints on bridge principles between logic and norms of reasoning, which would otherwise stand in a tension. (shrink)

ABSTRACT This part of the series has a dual purpose. In the first place we will discuss two kinds of theories of proof. The first kind will be called a theory of linear proof. The second has been called a theory of suppositional proof. The term "natural deduction" has often and correctly been used to refer to the second kind of theory, but I shall not do so here because many of the theories so-called are not of the second (...) kind--they must be thought of either as disguised linear theories or theories of a third kind (see postscript below). The second purpose of this part is 25 to develop some of the main ideas needed in constructing a comprehensive theory of proof. The reason for choosing the linear and suppositional theories for this purpose is because the linear theory includes only rules of a very simple nature, and the suppositional theory can be seen as the result of making the linear theory more comprehensive. CORRECTION: At the time these articles were written the word ‘proof’ especially in the phrase ‘proof from hypotheses’ was widely used to refer to what were earlier and are now called deductions. I ask your forgiveness. I have forgiven Church and Henkin who misled me. (shrink)

We explore new connections between the epistemologies of mental rehearsal and suppositional reasoning to offer a novel perspective on skilled behavior and its relationship to practical knowledge. We argue that practical knowledge is "easy" in the sense that, by manifesting one's skills, one has a priori propositional justification for certain beliefs about what one is doing as one does it. This proposal has wider consequences for debates about intentional action and knowledge: first, because agents sometimes act intentionally in (...) epistemically hazardous environments, these justified beliefs do not always rise to the level of (practical) knowledge. Second, practical knowledge is more intimately related to basic knowledge than has been appreciated. Third, an attractive "middle way" opens between the Anscombian tradition of defending a necessary connection between intentional action and practical knowledge and the more recent tradition of explaining away substantive epistemic conditions on intentional action. (shrink)

In this paper, I explore a question about deductive reasoning: why am I in a position to immediately infer some deductive consequences of what I know, but not others? I show why the question cannot be answered in the most natural ways of answering it, in particular in Descartes’s way of answering it. I then go on to introduce a new approach to answering the question, an approach inspired by Hume’s view of inductive reasoning.

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)

We offer a model of moral reform and regeneration that involves a wrong-doer making two movements: on the one hand, he identifies with himself as the one who did the act, while he also intentionally moves away from that self (or set of desires and intentions) and moves toward a transformed identity. We see this model at work in the formal practice of contrition and reform in Christian and Buddhist rites. This paper is part of a broader project we are (...) undertaking on the philosophy of forgiveness. (shrink)

In contemporary discussions of the Ramsey Test for conditionals, it is commonly held that (i) supposing the antecedent of a conditional is adopting a potential state of full belief, and (ii) Modus Ponens is a valid rule of inference. I argue on the basis of Thomason Conditionals (such as ' If Sally is deceiving, I do not believe it') and Moore's Paradox that both claims are wrong. I then develop a double-indexed Update Semantics for conditionals which takes these two results (...) into account while doing justice to the key intuitions underlying the Ramsey Test. The semantics is extended to cover some further phenomena, including the recent observation that epistemic modal operators give rise to something very like, but also very unlike, Moore's Paradox. (shrink)

We argue that relating to myself as me provides, as such, a reason to care about myself: grasping that an event involves me, instead of another, makes it matter in a special way. Further, this self-concern is not simply a matter of seeing in myself some instrumental value for other ends. We use as our foil a recent skeptical challenge to this view offered in Setiya 2015. We think the case against self-concern is powered by unwarrantedly narrow construals of three (...) key notions. One is the notion of a first-personal way of relating to oneself. A narrow account of the first person in terms of special epistemic relations to oneself makes it easy to overlook a source of non-instrumental reasons of self-concern, located in the special relation a subject has to herself as agent. Two is the notion of what it is to be a reason. And, three, is the notion of self-concern itself. We show that the skeptical case rests in part on a slide towards neighbouring but distinct notions of egoism and selfishness. We also argue that Setiya’s notion of self-love, offered to capture the pre-theoretical intuition of self-concern, cannot do it justice. (shrink)

Conceptual engineering involves revising our concepts. It can be pursued as a specific philosophical methodology, but is also common in ordinary, non-philosophical, contexts. How does our capacity for conceptual engineering fit into human cognitive life more broadly? I hold that conceptual engineering is best understood alongside practices of conceptual exploration, examples of which include conceptual supposition (i.e., suppositional reasoning about alternative concepts), and conceptual comparison (i.e., comparisons between possible concept choices). Whereas in conceptual engineering we aim to change (...) the concepts we use, in conceptual exploration, we reason about conceptual possibilities. I approach conceptual exploration via the linguistic tools we use to communicate about concepts, using metalinguistic negotiation, convention-shifting conditionals, and metalinguistic comparatives as my key examples. I present a linguistic framework incorporating conventions that can account for this communication in a unified way. Furthermore, I argue that conceptual exploration helps undermine skepticism about conceptual engineering itself. (shrink)

Some believe that all arguments make an implicit “inference claim” that the conclusion is inferable from the premises (e.g., Bermejo-Luque, Grennan, the Groarkes, Hitchcock, Scriven). I try to show that this is confused. An act of arguing arises because an inference can be attributed to us, not a meta-level “inference claim” that would make the argument self-referential and regressive. I develop six (other) possible explanations of the popularity of the doctrine that similarly identify confusions.

This paper encapsulates the debate as to whether or not tarka is an additional source of knowledge. In this regard, Jaina thinkers opine that they are, unlike Buddhists and Nyāya thinkers, an additional source of knowledge, for what we come to know through tarka is not known through any other means of knowledge. En route, Jaina’s understanding of tarka is put forth, thereafter their criticism of others’ understanding is supplied. Eventually, some recent discussions over this debate are intimated that seem (...) to go in support of Jaina understanding of tarka. These recent discussions hint at the direction in which Jaina thinkers need to advance their stand. (shrink)

ABSTRACT: In this paper I argue (i) that the hypothetical arguments about which the Stoic Chrysippus wrote numerous books (DL 7.196) are not to be confused with the so-called hypothetical syllogisms" but are the same hypothetical arguments as those mentioned five times in Epictetus (e.g. Diss. 1.25.11-12); and (ii) that these hypothetical arguments are formed by replacing in a non-hypothetical argument one (or more) of the premisses by a Stoic "hypothesis" or supposition. Such "hypotheses" or suppositions differ from propositions in (...) that they have a specific logical form and no truth-value. The reason for the introduction of a distinct class of hypothetical arguments can be found in the context of dialectical argumentation. The paper concludes with the discussion of some evidence for the use of Stoic hypothetical arguments in ancient texts. (shrink)

In natural language, conditionals are frequently used for giving explanations. Thus the antecedent of a conditional is typically understood as being connected to, being relevant for, or providing evidential support for the conditional's consequent. This aspect has not been adequately mirrored by the logics that are usually offered for the reasoning with conditionals: neither in the logic of the material conditional or the strict conditional, nor in the plethora of logics for suppositional conditionals that have been produced over (...) the past 50 years. In this paper I survey some recent attempts to come to terms with the problem of encoding evidential support or relevance in the logic of conditionals. I present models in a qualitative-modal and in a quantitative-probabilistic setting. Focussing on some particular examples, I show that no perfect match between the two kinds of settings has been achieved yet. (shrink)

Suppose that two competing norms, N1 and N2, can be identified such that a given person’s response can be interpreted as correct according to N1 but incorrect according to N2. Which of these two norms, if any, should one use to interpret such a response? In this paper we seek to address this fundamental problem by studying individual variation in the interpretation of conditionals by establishing individual profiles of the participants based on their case judgments and reflective attitudes. To investigate (...) the participants’ reflective attitudes we introduce a new experimental paradigm called the Scorekeeping Task. As a case study, we identify the participants who follow the Suppositional Theory of conditionals (N1) versus Inferentialism (N2) and investigate to what extent internally consistent competence models can be reconstructed for the participants on this basis. After extensive empirical investigations, an apparent reasoning error with and-to-if inferences was found in one of these two groups. The implications of this case study for debates on the proper role of normative considerations in psychology are discussed. (shrink)

Agency is an amazing thing: it transduces cognitivity into causality, it makes thought real. How it does so has been a matter of considerable dispute, the resolution of which has been hampered by moral complications. The supposition of a rational basis for morality can play an essential role in clarifying agency by providing a ground for legitimizing the objects of desire and the motivation they provide. The four-stage model of agency presented here – deliberation, calculation, intention, and enactment – emerges (...) when the moral concerns regarding desire have been detoxified. A crucial distinction is between the cognitive and causal aspects of desire, between the estimation of desirability (preference) and the actual motivation it may initiate (desire). Failure to recognize desire’s cognitive aspect preemptively disables its participation in practical reasoning. (shrink)

The fallacy fallacy is either the misdiagnosis of fallacy or the supposition that the conclusion of a fallacy must be a falsehood. This paper explores the relevance of these and related errors of reasoning for the appraisal of arguments, especially within virtue theories of argumentation. In particular, the fallacy fallacy exemplifies the Owl of Minerva problem, whereby tools devised to understand a norm make possible new ways of violating the norm. Fallacies are such tools and so are vices. Hence (...) a similar problem arises with argumentative vices. Fortunately, both instances of the problem have a common remedy. (shrink)

Recently several papers have reported relevance effects on the cognitive assessments of indicative conditionals, which pose an explanatory challenge to the Suppositional Theory of conditionals advanced by David Over, which is influential in the psychology of reasoning. Some of these results concern the “Equation” (P(if A, then C) = P(C|A)), others the de Finetti truth table, and yet others the uncertain and-to-inference task. The purpose of this chapter is to take a Birdseye view on the debate and investigate (...) some of the open theoretical issues posed by the empirical results. Central among these is whether to count these effects as belonging to pragmatics or semantics. (shrink)

Fictionalists propose that some apparently fact-stating discourses do not aim to convey factual information about the world, but rather allow us to engage in a fiction or pretense without incurring ontological commitments. Some philosophers have suggested that using mathematical, modal, or moral discourse, for example, need not commit us to the existence of mathematical objects, possible worlds, or moral facts. The mental fictionalist applies this reasoning to our mental discourse, suggesting that we can use ‘belief’ and ‘desire’ talk without (...) committing to the existence of beliefs and desires as mental entities. Most arguments for mental fictionalism are based on two key suppositions: first, that there are ontological concerns about mental entities; and second, that these ontological concerns justify a fictionalist interpretation of mental discourse. This paper challenges both suppositions and argues that the standard arguments for mental fictionalism are substantially weaker than arguments for other forms of fictionalism in the philosophical literature. (shrink)

The problem of probabilities of conditionals is one of the long-standing puzzles in philosophy of language. We defend and update Adams' solution to the puzzle: the probability of an epistemic conditional is not the probability of a proposition, but a probability under a supposition. -/- Close inspection of how a triviality result unfolds in a concrete scenario does not provide counterexamples to the view that probabilities of conditionals are conditional probabilities: instead, it supports the conclusion that probabilities of conditionals violate (...) standard probability theory. -/- This does not call into question probability theory per se; rather, it calls for a more careful understanding of its role: probability theory is a theory of probabilities of propositions; but as conditionals do not express propositions, their probabilities are not subject to the standard laws. -/- We argue that both conditional probabilities and probabilities of conditionals are best understood in terms of the dynamics of supposing, modeled as a restriction operation on a probability space. This version of the suppositionalist view allows us to connect Adams' Thesis to the widely held restrictor view of the semantics of conditionals. -/- We address two common objections to Adams' view: that the relevant probabilities are ‘probabilities only in name’, and that giving up conditional propositions puts us at a disadvantage when it comes to interpreting compounds. -/- Finally, we argue that some putative counterexamples to Adams' Thesis can be diagnosed as fallacies of probabilistic reasoning: they arise from applying to conditionals laws of standard probability theory which are invalid for them. (shrink)

Why are conditional degrees of belief in an observation E, given a statistical hypothesis H, aligned with the objective probabilities expressed by H? After showing that standard replies are not satisfactory, I develop a suppositional analysis of conditional degree of belief, transferring Ramsey’s classical proposal to statistical inference. The analysis saves the alignment, explains the role of chance-credence coordination, and rebuts the charge of arbitrary assessment of evidence in Bayesian inference. Finally, I explore the implications of this analysis for (...) Bayesian reasoning with idealized models in science. (shrink)

This paper argues that a necessary condition on inferential knowledge is that one knows all the propositions that knowledge depends on. That is, I will argue in support of a principle I call the Knowledge from Knowledge principle: (KFK) S knows that p via inference or reasoning only if S knows all the propositions on which p depends. KFK meshes well with the natural idea that (at least with respect to deductively valid or induc- tively strong arguments) the epistemic (...) status of one’s belief in the conclusion of an argument is a function of the epistemic status of the attitudes one has to the premises of that argument. One gets what one puts in: S’s belief in the conclusion C of an argument A has epistemic status E for S only if S’s belief in each of the premises C depends on also has epistemic status E.1 This is compatible, of course, with the epistemic status of S’s conclusion being greater than the epistemic status of the premises on which the conclusion of her reasoning depends. Furthermore, even though KFK applies more straightforwardly to non-suppositional inferences, we can also plausibly apply the principle to sup- positional reasoning if we treat S’s assuming for the sake of argument that p,2 as S assuming for the sake of argument that she knows that p.3 Although extremely plausible, philosophers have failed to present a concerted case in support of KFK. Most of their energy goes to articulating and/or defending some form of closure principle for knowledge.4 What is more, recently versions of this principle have been dismissed as problematic but I think without the reasons in its support been fully appreciated. This paper is an e fort to change the current state of affairs. Its focus is positive, however: my goal is to make the best case I can in support of KFK.5 To that end, the paper presents the reasons we have to accept KFK (§1), consid- ers an objection to the principle (§2), and situates the principle in the broader normative context of knowledge norms (§3). (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)

This article defends three claims. First, that collection and division in the Phaedrus are described as procedures that underlie human speaking and thinking in general, as well as philosophical inquiry, and are not identified with either. Second, that what sets the dialectical use of these procedures apart from their ordinary use are philosophical suppositions independent of the procedures of collection and division themselves; for that reason, collection and division cannot be identified with dialectic as such. Third, that the second part (...) of the Phaedrus is concerned with the broader question how noble or beautiful speaking, in general, may be said to depend on dialectic as much as it is concerned with the question how rhetoric, as a kind of expertise, is related to dialectic. (shrink)

The aim is to motivate theoretically a relevance approach to conditionals in a comparative discussion of the main alternatives. In particular, it will be argued that a relevance approach to conditionals is better motivated than the suppositional theory currently enjoying wide endorsement. In the course of this discussion, an argument will be presented for why failures of the epistemic relevance of the antecedent for the consequent should be counted as genuine semantic defects. Furthermore, strategies for dealing with compositionality and (...) the perceived objective purport of indicative conditionals will be put forward. (shrink)

Can fictional narration yield knowledge in a way that depends crucially on its being fictional? This is the hard question of literary cognitivism. It is unexceptional that knowledge can be gained from fictional literature in ways that are not dependent on its fictionality (e.g., the science in science fiction). Sometimes fictional narratives are taken to exhibit the structure of suppositional argument, sometimes analogical argument. Of course, neither structure is unique to narratives. The thesis of literary cognitivism would be supported (...) if some novels exhibit a cogent and special argument structure restricted to fictional narratives. I contend that this is the case for a kind of transcendental argument. The reason is the inclusion and pattern of occurrence of the predicate ‘believable’ in the schema. Believability with respect to fictional stories is quite a different thing than it is with respect to nonfictional stories or anything else. (shrink)

The purpose of this paper is to explain and discuss Leibniz’s main objections to the Molinist-Suárezian voluntarist (libertarian) conception of freedom, i.e., the conception involving the supposition of “freedom of indifference” of the will to make contrary choices in exactly the same circumstances. Leibniz’s main objections to the voluntarist conception are the following: (i) it violates the Principle of Sufficient Reason; (ii) it is based on a mistaken picture of the nature of the will.

David Bloor’s thought experiment is taken into consideration to suggest that the rationality of the Other cannot be inferred by way of argument for the reason that it is unavoidably contained as a hidden supposition by any argument engaged in proving it. We are able to understand a different culture only as far as we recognize in it the same kind of rationality that works in our own culture. Another kind of rationality is either impossible, or indiscernible.

Debate between the A- and B-theories has rested on the supposition that there is a clear difference between A- and B-time. I argue that this supposition is mistaken for two reasons. We cannot distinguish the two conceptions of time by means of Bergsonian intuition. Unless we can do so, we cannot distinguish them at all. I defend by imagining various ways to intuit the two kinds of time, and maintaining that none of them works. I defend by showing that the (...) issue is an experiential one, unlike metaphysical issues that are less connected to experience. My conclusion is that no progress will be made in the debate between the two theories until it becomes clear what the difference is between the two kinds of time. (shrink)

In this paper I consider an argument for the possibility of intending at will, and its relationship to an argument about the possibility of believing at will. I argue that although we have good reason to think we sometimes intend at will, we lack good reason to think this in the case of believing. Instead of believing at will, agents like us often suppose at will.

Some consequentialists argue that ordinary individuals are obligated to act in specific, concrete ways to address large-scale harms. For example, they argue that we should each refrain from meat-eating and avoid buying sweatshop-made clothing. The case they advance for such prescriptions can seem intuitive and compelling: by acting in those ways, a person might help prevent serious harms from being produced at little or no personal cost, and so one should act in those ways. But I argue that such (...) class='Hi'>reasoning often relies on an overly simplistic assessment of the costs and benefits of those prescriptions, one that misconstrues or neglects important issues. Indeed, a closer look at those costs and benefits reveals just how little we often know about a number of real-world matters that bear on the expected consequences of the prescribed individual actions. Our predicament is one of radical uncertainty: we currently lack a sound basis for concluding that the relevant actions are more likely to do good than to backfire. I distinguish this empirically grounded objection from others, which are not convincing—including one based on the mere conceivability of the actions in question backfiring and another based on the supposition that such actions cannot make a difference in addressing the massive problems at issue. The upshot is that, at least for now, consequentialist arguments for many specific individual actions aimed at addressing large-scale harms are inconclusive. (shrink)

The argument that follows has a certain air of prestidigitation about it. I attempt to show that, given a couple of innocent-seeming suppositions, it is possible to derive a positive and complete theory of normative ethics from the Humean maxim "You can't get ought from is." This seems, of course, absurd. If the reasoning isn't completely unhinged, you may be sure, the trick has to lie in those "innocent-seeming" props. And, in fact, you are right. But every argument has (...) to begin somewhere, and, however questionable, those suppositions just don't seem to harbor serious normative import. (shrink)

Casting directors are tasked with selecting a suitable actor for a given role. “Suitable” in this context typically means possessing a combination of physical attributes and acting skills. But are there any moral constraints on the choice? I argue that there are. This is an uncommon supposition, and few even entertain the question. In this essay, I discuss the reasons for this omission and attempt to make up for it.

Descartes insists, “[...] there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me. In that case I too undoubtedly exist, if he is deceiving me [...]” (AT-VII, 25; CSM-II, 17). In what way can we draw evidence that our existence can be drawn from our being deceived? The interpretations that the earlier studies have shown is not a monolith. Then I will search for some inherent characteristics of deception, and analyse the construction of the (...) reasoning, “if a deceiver deceives me, I exist.” To be concrete, I show: 1) that it is not “I exist” but “I think” that is concluded from the supposition “a deceiver deceives me/I am deceived by a deceiver”; 2) that the attributions of the self as a thinking thing, i.e. understanding, affirming, and denying (AT-VII, 28; CSM-II, 19), are discovered in the very supposition of a deceiver. (shrink)

Popper's account of refutation is the linchpin of his famous view that the method of science is the method of conjecture and refutation. This thesis critically examines his account of refutation, and in particular the practice he deprecates as avoiding a refutation. I try to explain how he comes to hold the views that he does about these matters; how he seeks to make them plausible; how he has influenced others to accept his mistakes, and how some of the ideas (...) or responses to Popper of such people are thus similarly mistaken. I draw some distinctions necessary to the provision of an adequate account of the so-called practice of avoiding a refutation, and try to rid the debate about this practice of at least one red herring. I analyse one case of 'avoiding' a refutation in detail to show how the rationality of scientific practice eludes both Popper and many of his commentators. Popper's skepticism about contingent knowledge prevents him from providing an acceptable account of contingent refutation, and so his method is really the method of conjecture and conjecture. He cannot do without the concepts of knowledge and refutation, however, if his account of science is to be plausible or persuasive, and so he equivocates between, amongst other things, refutation as disproof and refutation as the weaker notion of discorroboration. I criticise David Stove's account of this matter, in particular to show how he misses this point. An additional advantage Popper would secure from this equivocation is that if refutations were mere discorroborations they would be easier to achieve, and hence more common in science, than is the case. On Popper's weak notion of refutation, it would be possible to refute true theories since corroboration does not entail truth. There are two other related doctrines Popper holds about refutation which, if accepted, make some refutations seem easier to obtain than is the case. I call these doctrines 'Strong Popperian Falsificationism' (SPF) and 'Weak Popperian Falsificationism' (WPF). SPF is the false doctrine that if a prediction from some theory is refuted then that theory is refuted. Popper does not always endorse SPF. In particular, when confronted with a counterexample to it, he retreats to WPF, which is the false doctrine that if a prediction from some theory is refuted then that theory is prima facie refuted. WPF , or even SPF, can seem plausible if one has in mind predictions derived from theories in strong or conclusive tests of those theories, which I suggest Popper characteristically does. v Popper is disposed to describe any such case of predictive failure which does not lead to the refutation of the theory concerned as one in which that refutation has been avoided. To reinforce his portrayal of the refutation, or the attempted refutation, of major scientific theories as the rational core of scientific practice, Popper treats the so-called practice of avoiding a refutation as untypical of science, and much so-called avoidance he dismisses as unscientific or pseudo-scientific. I argue that his notion of avoiding a refutation is incoherent. Popper is further driven to believe that such avoidance is possible, however, because he conflates sentences with propositions and propositions with propositional beliefs. Also, he wishes to avoid being saddled with the relativisim that is a consequence of his weak account of refutation as discorroboration. Popper believes that ad hoc hypotheses are the most important of the unscientific means of avoiding a refutation. I argue that his account of such hypotheses is also incoherent, and that several hypotheses thought to be ad hoc in his sense are not. Such hypotheses appear to be so largely because of Popper's use of rhetoric and partly because these hypotheses are unacceptable for other reasons. I conclude that to know that a hypothesis is ad hoc in Popper's sense does not illuminate scientific practice. Popper has also attempted to explicate ad hocness in terms of some undesirable, or allegedly undesirable, properties of hypotheses or the explanations they would provide. The first such property is circularity, which is undesirable; the second such property is reduction in empirical content, which is not. In the former case I argue that non-circularity is clearly preferable to non-ad hocness as a criterion for a satisfactory explanation or explanans, as the case may be, and in the latter case that Popper is barking up the wrong tree. Some cases of so-called avoidance are obviously not unscientific. The discovery of Neptune from a prediction based on the reasonable belief that there were residual perturbations in the motion of Uranus is an important case in point, and one that is much discussed in the literature. The manifest failure of astronomers to account for Uranus's motion did not lead to the refutation of Newton's law of gravitiation, yet significant scientific progress obviously did result. Retreating to WPF, Popper claims that Newton's law was prima facie refuted. In general, astronomers have never shared this view, and they are correct in not doing so. I argue that the law of gravitation would have been prima facie refuted only if there had been good reason at the time to believe as false what is true, namely, that an unknown trans-Uranian planet was the cause of those Uranian residuals. Knowledge of the trans-Uranian region was then so slight that it was merely a convenient assumption, one which there was little reason to believe was false, that the known influences on Uranus's motion were the only such influences. I conclude that in believing vi or supposing that it was this assumption that was false, rather than the law of gravitation, Leverrier and Adams, the co-predictors of Neptune, were acting rationally and intelligently. Popper's commentators offer a variety of accounts of the alleged practice of avoiding a refutation, and of this case in particular. I analyse a sample of their accounts to show how common is the acceptance of some of Popper's basic mistakes, even amongst those who claim to reject his falsificationism, and to display the effects on their accounts of this acceptance of his mistakes. Many commentators recognize that anomalies are typically dealt with by changes in the boundary conditions or in other of the auxiliary propositions employed. Where many still go wrong, however, is in retaining the presupposition of WPF which encouraged Popper to hold the contradictory view about anomalies in the first place. Thus Imre Lakatos and others, for example, have developed a 'siege mentality' about major scientific theories; they see them as under continual threat of refutation from anomalies, and so come to believe that dogmatism is essential in science if such theories are to survive as they do. I examine various such doomed attempts to reconcile Popper with the history of science. It is a common failure in this literature to conflate or to fail to see the need to distinguish a belief from a supposition, and an epistemic reason from a pragmatic reason. I argue that only if one does draw these distinctions can one give an adequate account of how anomalies are rationally dealt with in science. The other important strand in Popper's thinking about 'avoidance' of refutation which has seriously misled some of his commentators is his unfounded belief in the dangers of ad hoc hypotheses. I examine the accounts that a sample of such commentators provide of the trans-Uranian planet hypotheses of Leverrier and Adams. These commentators imply or assert what Popper only hints at, namely, that there is something fishy about this hypothesis. I provide a further defence of the rationality of entertaining this hypothesis at the time. I conclude with a few remarks about Popper's dilemma in respect of scientific practice and his long standing emphasis on refutations. (shrink)

Since the early 1990s, Uganda has been cajoled by the IMF and World Bank to pursue a neo-liberal approach to development as opposed to a liberal development modus operandi. However, in theory the World Bank has pursued a liberal, rights based approach to poverty reduction policy but, in practice, it has implemented a neo-liberal, market centric approach to poverty reduction. This is the reason why pro-poor poverty reduction in Uganda is more of rhetorical than practical. This paper critiques the epistemological (...) pre-suppositions characteristic of the ethics of the current pro-poor poverty policy in Uganda. The fundamental premises of this critique are: Can the views of the poor in Uganda influence poverty policies given their asymmetrical disadvantage? Who knows the views of poor? Do the elites interpret the views of the poor as they are or as they think them to be? Do the poor have poverty knowledge or poverty opinion? Are some of the views of the poor simply adaptive preferences? What constitutes poverty knowledge as opposed to poverty opinion? Is it ethical to eradicate poverty using opinion riddled poverty polices? Is it ethically sustainable for poverty policies to persistently aim at integrating women in poverty eradication interventions while largely giving lip service patriarchal power relations that asymmetrically disadvantage them? (shrink)

The scientific study of socio-cultural phenomenon requires a translocation of topics elaborated from the social perspective of the individual to a rationally ordered rendition of processes suitable for comprehension from a scientific perspective. Scholarly curiosity seeded from exposure in the natural setting to economic, political, socio-cultural, evolutionary, processes dictates that study of the self, should be a science with a necessary place in the body of world literatures; yet it has proven difficult to find a perspective to contain discussions of (...) topics in a coherent manner for scientific approach: for example, anthropology, the study of mankind, finds difficulty elaborating definition for the orientation of study; it is a member of the same set that contains it. In this presentation, based on features indigenous to a supposed distant perspective that is exposed employing experiences of history and criteria of common sensory perception, it is conjectured that a civilization lifetime pathology is contemporarily active. Example is taken from philosophical and sociological discourses, modern science theory, medicine in pursuit of international health issues, to capture conceptually a role of motions of external agents occurred within the interval of observation, elaboration of concepts, choice of directions, as a source of paradox and confusion. In supposition that does not escape simple logic, ubiquitously appealing to the experience bound senses for understanding, hidden motions, common to both observer and observed, are hypothesized to render from a sense of familiarity, a continued frustration in attaining an understanding of the self and nature. A psychical seduction is proposed to exist, related to historical behaviors associated with centrism and asceticism, produces eccentric interpretations that are bound modernly to logical circular, centric geometrical reasonings; world conceptualizations are conjectured to acquire an avoidance of a state of ‘motionless’ rather than death within selection processes. Projection by the imagination upon the unknown is conjectured to result in a seduction by an active ‘live-wire” embodied to motions occurred to a distant surface. (shrink)

Suppositional theories of conditionals take apparent similarities between supposition and conditionals as a starting point, appealing to features of the former to provide an account of the latter. This paper develops a novel form of suppositional theory, one which characterizes the relationship at the level of semantics rather than at the level of speech acts. In the course of doing so, it considers a range of novel data which shed additional light on how conditionals and supposition interact.