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.

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 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)

Elizabeth Karger has suggested an interpretation of Ockham's theory of the modes of common personal supposition ("TM") according to which the purpose of TM is to provide certain distinctions that Ockham will use in formulating a unified theory of immediate inference among certain kinds of sentences. Karger presents a single, powerful rule of inference that incorporates TM distinctions and that is meant to codify Ockham's theory of immediate inference. I raise an objection to Karger's rule, thereby (...) calling into doubt the interpretation of Ockham that is based on attributing that rule to him. (shrink)

This paper has as its topic two recent philosophical disputes. One of these disputes is internal to the project known as decision theory, and while by now familiar to many, may well seem to be of pressing concern only to specialists. It has been carried on over the last twenty years or so, but by now the two opposing camps are pretty well entrenched in their respective positions, and the situation appears to many observers (as well as to some (...) of the parties involved) to have reached a sort of stalemate. The second of these two disputes is, on the other hand, very much alive. While it has been framed in decision theoretic terms, it is definitely not a dispute internal to that enterprise. It is, rather, a debate about the very coherence of the notion of objective value, and as such touches on issues of central importance to, for example, meta–ethics and moral psychology. (shrink)

In this article, we discuss the notion of merely confused supposition as it arose in the medieval theory of suppositio personalis. The context of our analysis is our formalization of William of Ockham's theory of supposition sketched in Mind 86 (1977), 109-13. The present paper is, however, self-contained, although we assume a basic acquaintance with supposition theory. The detailed aims of the paper are: to look at the tasks that supposition theory took (...) on itself and to use our formalization to relate them to more modern ideas; to explain the notion of merely confused supposition and to defend it against certain criticisms; and to discuss two issues closely related to the idea of merely confused supposition which we could not broach in a shorter article: the mode of supposition of terms in intensional contexts, and the possible existence of a fourth mode, often called suppositio copulatim. (shrink)

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)

Suppositions can be introduced in either the indicative or subjunctive mood. The introduction of either type of supposition initiates judgments that may be either qualitative, binary judgments about whether a given proposition is acceptable or quantitative, numerical ones about how acceptable it is. As such, accounts of qualitative/quantitative judgment under indicative/subjunctive supposition have been developed in the literature. We explore these four different types of theories by systematically explicating the relationships canonical representatives of each. Our representative qualitative accounts (...) of indicative and subjunctive supposition are based on the belief change operations provided by AGM revision and KM update respectively; our representative quantitative ones are offered by conditionalization and imaging. This choice is motivated by the familiar approach of understanding supposition as `provisional belief revision' wherein one temporarily treats the supposition as true and forms judgments by making appropriate changes to their other opinions. To compare the numerical judgments recommended by the quantitative theories with the binary ones recommended by the qualitative accounts, we rely on a suitably adapted version of the Lockean thesis. Ultimately, we establish a number of new results that we interpret as vindicating the often-repeated claim that conditionalization is a probabilistic version of revision, while imaging is a probabilistic version of update. (shrink)

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)

It can often seem like the attitude we hold towards a conditional should be our attitude in the consequent on the supposition of the antecedent. Following by Williamson (Suppose and Tell: The Semantics and Heuristics of Conditionals. Oxford University Press, 2020), we call this The suppositional rule (SR). The Adams-style non-propositional theories of indicatives upholds some key implications of SR, allowing, for instance, our credence in a conditional to be the probability of the consequent given the antecedent. Williamson (Suppose (...) and Tell: The Semantics and Heuristics of Conditionals. Oxford University Press, 2020) has recently provided a series of inconsistency arguments against SR. He thereby intends to undermine non-propositional views as well as other rivals to his favoured material conditional account. I outline a strategy which theorists of all stripes can employ to avoid Williamson’s arguments. I then show how non-propositionalists can implement this strategy. I show how they can uphold SR when it is intuitively compelling, whilst allowing it to fail when it is not. (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)

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.

*These notes were folded into the published paper "Probability and nonclassical logic*. Revising semantics and logic has consequences for the theory of mind. Standard formal treatments of rational belief and desire make classical assumptions. If we are to challenge the presuppositions, we indicate what is kind of theory is going to take their place. Consider probability theory interpreted as an account of ideal partial belief. But if some propositions are neither true nor false, or are half true, (...) or whatever—then it’s far from clear that our degrees of belief in it and its negation should sum to 1, as classical probability theory requires (?, cf.). There are extant proposals in the literature for generalizing (categorical) probability theory to a non-classical setting, and we will use these below. But subjective probabilities themselves stand in functional relations to other mental states, and we need to trace the knock-on consequences of revisionism for this interrelationship (arguably, degrees of belief only count as kinds of belief in virtue of standing in these functional relationships). (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)

I assess the thesis that counterfactual asymmetries are explained by an asymmetry of the global entropy at the temporal boundaries of the universe, by developing a method of evaluating counterfactuals that includes, as a background assumption, the low entropy of the early universe. The resulting theory attempts to vindicate the common practice of holding the past mostly fixed under counterfactual supposition while at the same time allowing the counterfactual's antecedent to obtain by a natural physical development. Although the (...) theory has some success in evaluating a wide variety of ordinary counterfactuals, it fails as an explanation of counterfactual asymmetry. (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)

The supposition that Wittgenstein's Tractatus advances a certain metaphysics has given rise to a controversy over the ontological status of his Tractarian objects. It has been debated, for instance, whether these objects consist only of particulars or of both particulars and universals; whether they are physical, phenomenal, or phenomenological entities; and whether they correspond to Russell's objects of acquaintance or Kant's phenomena and substance. In this essay, I endorse Ishiguro's view that these objects, being formal concepts, are ontologically neutral (...) and thus are not identifiable with any ontological kind of entities. I elaborate on the coherence of this view with the propositional dependence of the meaning of Tractarian names. After showing why some arguments for ascribing a Russellian theory of meaning to these names do not work, I demonstrate why Ishiguro's account of Tractarian objects and names provides a better explanation of the unalterability of these objects. (shrink)

A popular view has it that the mental representations underlying human pretense are not beliefs, but are “belief-like” in important ways. This view typically posits a distinctive cognitive attitude (a “DCA”) called “imagination” that is taken toward the propositions entertained during pretense, along with correspondingly distinct elements of cognitive architecture. This paper argues that the characteristics of pretense motivating such views of imagination can be explained without positing a DCA, or other cognitive architectural features beyond those regulating normal belief and (...) desire. On the present “Single Attitude” account of imagination, propositional imagining just is a form of believing. The Single Attitude account is also distinguished from “metarepresentational” accounts of pretense, which hold that both pretending and recognizing pretense in others require one to have concepts of mental states. It is argued, to the contrary, that pretending and recognizing pretense require neither a DCA nor possession of mental state concepts. (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)

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)

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)

In this manuscript we study individual variation in the interpretation of conditionals by establishing individual profiles of the participants based on their behavioral responses and reflective attitudes. To investigate the participants’ reflective attitudes we introduce a new experimental paradigm called the Scorekeeping Task, and a Bayesian mixture model tailored to analyze the data. The goal is thereby to identify the participants who follow the Suppositional Theory of conditionals and Inferentialism and to investigate their performance on the uncertain and-to-if inference (...) task. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Philosophy 42.2 (2004) 219-220 [Access article in PDF] Jack Zupko. John Buridan: Portrait of a Fourteenth-Century Arts Master. Notre Dame: University of Notre Dame Press, 2003. Pp. xix + 446. Cloth, $70.00. Paper, $40.00. What does the name "John Buridan" call to mind? For many, including medievalists, not much at all—at best, perhaps, a set of apparently unrelated ideas: nominalism; an impetus theory (...) of projectile motion; and a peculiar account of the will (although "Buridan's ass," the indecisive donkey caught between two equally appetizing bales of hay, is not found in Buridan's writing). In correcting this ignorance—an injustice to arguably the most famous and influential philosopher of the early-to-mid-fourteenth century—the temptation might have been to articulate Buridan's "positions" on "the big questions," allowing readers to fit Buridan into received categories. Thankfully, the present work, the first book-length study of Buridan in any language, resists this temptation. The John Buridan that emerges from Jack Zupko's skillful "exercise in philosophical portraiture" doesn't serve to simply fill gaps in our awareness of the historical record, but to enlighten and challenge our understanding of the practice of philosophy and the study of its history.Zupko emphasizes throughout that Buridan was a teacher, a master of arts in Paris. Buridan's pedagogical concerns help make sense of his central work in logic. As the basis for his arts lectures, Buridan chose Peter of Spain's Summulae Logicales, but in commenting on Peter, Buridan moves beyond creative exegisis to comprehensive renovation. Buridan (c. 1300-c. 1361) naturally wanted to accommodate terminist or via moderna supposition theory; but more importantly, he wanted a logic text that would set out a general plan of philosophical inquiry, "a compendium of methods, a 'how-to' book for the philosopher" (135). Buridan thus designed his own Summulae de Dialectica as a new authoritative logic text, and Zupko persuasively argues that its "nominalism" should be understood as less a set of doctrines in theoretical logic, than a program of logical practice, an education in logic as the ars artium, the universal intellectual tool.Zupko's portrait of "Buridan's vision of the philosophical enterprise" is thus appropriately divided into two parts. The first summarizes Buridan's method as described in the individual treatises of his Summulae. The second displays the method in practice, rehearsing and evaluating some of Buridan's arguments on various subjects. Many scholars will gravitate first to the latter part, where Zupko offers important interpretations and clarifications of Buridan's views. In these chapters, Zupko helps us to appreciate, among other things: how the problem of universals served to help Buridan define the scope of philosophy (ch. 10); the philosophical modesty of Buridan's account of the intellectual soul's presence in the body (ch. 11); the relationship between Buridan's epistemology and the skepticism of his Parisian contemporary Nicholas of Autrecourt (ch. 12); the sense in which Buridan is an "empiricist," viz an epistemic naturalist and reliabilist (ch. 13); how Buridan regarded moral psychology as applied physics, treating virtue as a kind of impetus (ch. 14); how Buridan's account of freedom can be regarded as a "perfection" of Thomistic intellectualism (ch. 15).Throughout these discussions, Zupko always keeps in sight his larger purpose of illustrating Buridan's conception of philosophical inquiry. Zupko makes much of the fact that [End Page 219] Buridan never wrote as a theologian, remaining his entire career in the arts faculty, where he wanted logic to organize secular inquiry. As Zupko notes, in this way Buridan's scholastic project seems to prefigure the "modern." But Buridan seems modern in another way as well. As Zupko points out in his "Introduction," though a cleric, Buridan never joined a religious order, so that his ideas developed independently of the Franciscan and Dominican traditions. He was, then, a teacher without a tradition—at least without deliberate allegiance to tradition, although he was in many ways the product of traditional scholastic intellectual discipline.Perhaps this... (shrink)

In a series of articles, David Barnett (2006, 2009, 2010) has developed a general theory of conditionals. The grand aim is to reconcile the two main rivals: a suppositional and a truth-conditional view (Barnett 2006, 521). While I confine my critical discussion to counterfactuals, I will give some hints how they might spell trouble for his suppositional view in general.

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)

My topic is how to make decisions when you possess foreknowledge of the consequences of your choice. Many have thought that these kinds of decisions pose a distinctive and novel problem for causal decision theory (CDT). My thesis is that foreknowledge poses no new problems for CDT. Some of the purported problems are not problems. Others are problems, but they are not problems for CDT. Rather, they are problems for our theories of subjunctive supposition. Others are problems, but (...) they are not new problems. They are old problems transposed into a new key. Nonetheless, decisions made with foreknowledge illustrate important lessons about the instrumental value of our choices. Once we've appreciated these lessons, we are left with a version of CDT which faces no novel threats from foreknowledge. (shrink)

Sensibility, in any of its myriad realms – moral, physical, aesthetic, medical and so on – seems to be a paramount case of a higher-level, intentional property, not a basic property. Diderot famously made the bold and attributive move of postulating that matter itself senses, or that sensibility (perhaps better translated ‘sensitivity’ here) is a general or universal property of matter, even if he at times took a step back from this claim and called it a “supposition.” Crucially, sensibility (...) is here playing the role of a ‘booster’: it enables materialism to provide a full and rich account of the phenomena of conscious, sentient life, contrary to what its opponents hold: for if matter can sense, and sensibility is not a merely mechanical process, then the loftiest cognitive plateaus are accessible to materialist analysis, or at least belong to one and the same world as the rest of matter. This was noted by the astute anti-materialist critic, the Abbé Lelarge de Lignac, who, in his 1751 Lettres à un Amériquain, criticized Buffon for “granting to the body [la machine, a common term for the body at the time] a quality which is essential to minds, namely sensibility.” This view, here attributed to Buffon and definitely held by Diderot, was comparatively rare. If we look for the sources of this concept, the most notable ones are physiological and medical treatises by prominent figures such as Robert Whytt, Albrecht von Haller and the Montpellier vitalist Théophile de Bordeu. We then have, or so I shall try to sketch out, an intellectual landscape in which new – or newly articulated – properties such as irritability and sensibility are presented either as an experimental property of muscle fibers, that can be understood mechanistically (Hallerian irritability, as studied recently by Hubert Steinke and Dominique Boury) or a property of matter itself (whether specifically living matter as in Bordeu and his fellow montpelliérains Ménuret and Fouquet, or matter in general, as in Diderot). I am by no means convinced that it is one and the same ‘sensibility’ that is at issue in debates between these figures (as when Bordeu attacks Haller’s distinction between irritability and sensibility and claims that ‘his own’ property of sensibility is both more correct and more fundamental in organic beings), but I am interested in mapping out a topography of the problem of sensibility as property of matter or as vital force in mid-eighteenth-century debates – not an exhaustive cartography of all possible positions or theories, but an attempt to understand the ‘triangulation’ of three views: a vitalist view in which sensibility is fundamental, matching up with a conception of the organism as the sum of parts conceived as little lives (Bordeu et al.); a mechanist, or ‘enhanced mechanist’ view in which one can work upwards, step by step from the basic property of irritability to the higher-level property of sensibility (Haller); and, more eclectic, a materialist view which seeks to combine the mechanistic, componential rigour and explanatory power of the Hallerian approach, with the monistic and metaphysically explosive potential of the vitalist approach (Diderot). It is my hope that examining Diderot in the context of this triangulated topography of sensibility as property sheds light on his famous proclamation regarding sensibility as a universal property of matter. (shrink)

Leading cosmological theories engender a controversial puzzle which has prompted philosophers to propose competing epistemological solutions and physicists to propose methodological changes to cosmology. The puzzle arises from the prediction that every brain on Earth will eventually be vastly outnumbered by physical duplicates formed by random collisions of particles in outer space. Supposing that this prediction is correct, shouldn't you believe that your brain is probably one of these vastly more typical extraterrestrial brains, since you cannot infer your brain's origin (...) from your experiential state? But supposing that your brain is one of these extraterrestrial brains, why be confident in the cosmological theories, since you never actually received testimony supporting these theories? Proposals in the literature either deny the rationality of believing theories that make the prediction or deny the typicality of your brain among its duplicates. This paper argues that these proposals are not entirely satisfactory. Instead, one should be confident in theories making the prediction on the supposition that your brain is one of the extraterrestrial brains. The upshots include that it may be rational to believe that your brain is probably an extraterrestrial brain and that cosmologists should not alter their methodology in response to the puzzle. (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)

Ce n'est pas en pensant que nous créons des mondes. C'est en comprenant le monde que nous apprenons à penser. La cosmovision est un terme qui devrait désigner un ensemble de fondements d'où émerge une compréhension systémique de l'Univers, de ses composantes comme la vie, le monde dans lequel nous vivons, la nature, le phénomène humain et leurs relations. C'est donc un champ de la philosophie analytique nourri par les sciences, dont l'objectif est cette connaissance agrégée et épistémologiquement soutenable de (...) tout ce que nous sommes et contenons, qui nous entoure, et qui nous concerne de quelques manières que ce soit. C'est quelque chose d'aussi vieux que la pensée humaine et, en plus d'utiliser des éléments de la cosmologie scientifique, il englobe tout ce qui, dans la philosophie et la science, se réfère à l'univers et à la vie. Une cosmovision n'est pas un ensemble d'idées, d'hypothèses et de suppositions, mais un système établi sur l'observation, l'analyse, la preuve et la démonstration. Aucune cosmovision n'entend définir, établir ou proposer, mais seulement comprendre, analyser et interpréter. Chacun de nous construit et transporte sa cosmovision tout au long de sa vie, sans établir de forme, comme toile de fond de nos pensées et de nos comportements. Linguistiquement, le terme « cosmovision » dériverait de l'allemand, équivalent au concept de « Weltanschauung », tel qu'il a été utilisé par plusieurs philosophes. Cependant, cette relation linguistique n'est pas applicable, car elle contredit ce que nous proposons comme cosmovision. Ce mot allemand fait référence à une vision prélogique ou proto-expérimentale de la réalité, avec un contexte intuitif et loin des connaissances critiques encore inexistantes au moment de sa formulation. Sans aucun doute, les cosmovisions, au sens où nous les entendons, abritent et utilisent ces éléments proto-expérimentaux ou prélogiques qui incluent l'histoire, l'inconscient collectif et tous les archétypes que nous portons. Or, dans le concept que nous appliquons ici, la cosmovision va bien au-delà de ce contenu, d'abord en le soumettant constamment à la pensée critique actuelle et enfin en faisant de l'expérience analytique (et non de la pensée elle-même ou de l'intuition) son univers réel. António Lopes expose l'étendue de ce contenu : [ ] « Les cosmovisions ne sont pas le produit de la pensée. Ils ne naissent pas du simple désir de savoir. L'appréhension de la réalité est un moment important dans sa configuration, mais, néanmoins, ce n'en est qu'un. Elle vient de la conduite vitale, de l'expérience de la vie, de la structure de notre totalité psychique. L'élévation de la vie à la conscience dans la connaissance de la réalité, dans l'évaluation de la vie et dans la réalité volitive est le travail lent et ardu que l'humanité a fait dans le développement des conceptions de la vie. (W.Dilthey, 1992 [1911] : 120). Dans cet ouvrage, nous cherchons à esquisser une cosmovision fondée sur les réalités que la science offre aujourd'hui. Nous ne proposons, à aucun moment, de faire de la science ; ou théoriser la philosophie, mais nous chercherons toujours à être soutenus par eux ou, du moins, protégés par eux des distorsions cognitives que nous portons habituellement. -/- . (shrink)

Ramseyan humility is the thesis that we cannot know which properties realize the roles specified by the laws of completed physics. Lewis seems to offer a sceptical argument for this conclusion. Humean fundamental properties can be permuted as to their causal roles and distribution throughout spacetime, yielding alternative possible worlds with the same fundamental structure as actuality, but at which the totality of available evidence is the same. On the assumption that empirical knowledge requires evidence, we cannot know which of (...) these worlds is actual. However, Lewis also appeals to a range of familiar semantic principles when framing his argument, which leads some authors to suppose that he can also plausibly be interpreted as offering a purely semantic argument for humility in addition. In this paper I grant that these arguments are Lewisian, but argue that Lewis is also committed to a theory of mind that licenses a purely metaphysical argument for humility based on the idea that mental properties supervene on fundamental structure. Given that knowing which x is the F requires knowing that a is the F, the supposition that we could come to know which properties actually occupy the fundamental roles entails differences in mental properties between worlds with the same fundamental structure, violating supervenience. Humility follows right away, without any further epistemic or semantic principles. This argument is immune to almost every way of rebutting the sceptical and semantic arguments; conversely, almost every way of rebutting the metaphysical argument tells equally against the others. (shrink)

This paper provides an account of what it is to have faith in a proposition p, in both religious and mundane contexts. It is argued that faith in p doesn’t require adopting a degree of belief that isn’t supported by one’s evidence but rather it requires terminating one’s search for further evidence and acting on the supposition that p. It is then shown, by responding to a formal result due to I.J. Good, that doing so can be rational in (...) a number of circumstances. If expected utility theory is the correct account of practical rationality, then having faith can be both epistemically and practically rational if the costs associated with gathering further evidence or postponing the decision are high. If a more permissive framework is adopted, then having faith can be rational even when there are no costs associated with gathering further evidence. (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)

We simply cannot make sense of Socrates' procedure for cross-examining his interlocutors in the early dialogues if we insist that Socrates uses cross-examination only for the purpose of testing his interlocutor's claim to knowledge. This view of Socratic cross-examination cannot explain the fact that Socrates examines theses that he himself proposes and that neither he nor his interlocutor explicitly endorses. In contrast,the supposition that Socrates is inquiring on these occasions provides a good explanation for his procedure. When one is (...) attempting to gain true belief and knowledge, it is important to consider the cases that can be made for hypotheses that one has never before considered, much less believed to be true. (shrink)

(1) Suppose that you care only about speaking the truth, and are confident that some particular deterministic theory is true. If someone asks you whether that theory is true, are you rationally required to answer "yes"? -/- (2) Suppose that you face a problem in which (as in Newcomb's problem) one of your options---call it "taking two boxes"---causally dominates your only other option. Are you rationally required to take two boxes? -/- Those of us attracted to causal decision (...) theory are under pressure to answer "yes" to both questions. However, it has been shown that many existing decision theories are inconsistent with doing so (Ahmed 2014). A simple proof shows that the same goes for an even wider class of theories: all "suppositional" decision theories. The moral is that causal decision theorists must either answer "no" to one of the above questions, or else abandon suppositional decision theories. (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 note considers the conceptual part of Sen’s «Internal Consistency of Choice». Amongst the various claims this paper features, two are singled out. A first, negative, claim is that no formal condition of choice consistency is normatively compelling without exception. A second, positive, claim, is that a formal condition of choice consistency is normatively compelling only under some assumptions involving preference. Here, the puzzling choices Sen puts forward are scrutinized and it is argued that such a scrutiny leads to question (...) the negative claim, but in a subtle way, so that the positive claim is comforted, even strengthened. -/- Cette note examine la partie conceptuelle d’un article de Sen, «Internal Consistency of Choice». Elle isole deux thèses parmi celles que Sen défend. Une première, négative, est qu’aucune condition formelle de cohérence du choix n’est normativement valable sans exception. Une seconde, positive, est qu’une condition formelle de cohérence du choix n’est normativement valable que sous des suppositions faisant intervenir la préférence. Nous procédons à une analyse détaillée des choix énigmatiques dont Sen prend argument et affirmons que cet examen mène à remettre en cause la thèse négative, mais d’une manière subtile qui confirme — même renforce — la thèse positive. (shrink)

Current debate in the metaphysics of time ordinarily assumes that we should be realists about time. Recently, however, a number of physicists and philosophers of physics have proposed that time will play no role in a completed theory of quantum gravity. This paper defends fictionalism about temporal thought, on the supposition that our world is timeless. We argue that, in the face of timeless physical theories, realism about temporal thought is unsustainable: some kind of anti-realism must be adopted. (...) We go on to provide an argument against eliminativism about temporal thought. While it doesn't follow from this argument that fictionalism about temporal thought is true, we suggest that this nonetheless shows that fictionalism should be regarded as the preferred view. (shrink)

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)

This paper seeks to explain and evaluate, by an analytic method, the conflict between determinism and free will from the viewpoint of two physicalist reductionist philosophers, namely, Daniel Dennett and Sam Harris. Dennett is a compatibilist philosopher who tries to show compatibility between determinism and free will, while Sam Harris is a non-compatibilist philosopher who turns to determinism with the thesis that our thoughts and actions have been pre-determined by the neurobiological events associated with them, and thus, considers free will (...) to be an illusion. Therefore according to him, we are not the authors of our thoughts and actions. However, Dennett tries to establish the existence of free will through the use of concepts like control and deliberation and defends ‘free will worth wanting’. Therefore, if we take the agency of the agent and the absence of determinism as two criteria for free will, Dennett accepts both and Harris denies them; since there is neurobiological determinism, and all of Dennett’s deliberations, etc. are also determined neurobiologically. Between the two conditions of free will, Dennett accepts that the origin of action must be in the agent; however, he refutes the condition of alternate possibilities, establishing his view based on a causal theory. As a Neo-Darwinist, he explains human beings’ physical and mental phenomena based on evolution theory and despite accepting causal determinism, he shows how the agent can still have agency in decisions and actions. As a result, he does not consider determinism to requisite compulsion. In his philosophical system, one can change the future that has not yet taken place. This decision-making regarding the future takes place through the process of deliberation, which has a special place in Dennett’s view. On the other hand, by adhering to Libet’s neurological experiments, Harris refutes both conditions of free will and considers the cause of all human being actions to arise from activities of the brain and concludes that one cannot have any conscious control over one’s actions. As a result, he emerges as a non-compatibilist determinist. In both his works, The Moral Landscape and Free Will, Harris addresses the topic of free will. In Free Will, he criticizes the view of compatibilists like Dennett, who responds to those criticisms in his article, ‘Reflections on Free Will, Review of Sam Harris’ Free Will’. Like Harris, Dennett too addresses free will in his two important books, Elbow Room and Freedom Evolves. Following an analysis of the views of Dennett and Harris and explaining the criticisms of the two regarding each other, the present article will show that neither Dennett, considering the rest of the elements of his philosophical views in philosophy of mind and philosophy of action can well justify compatibilism, nor can Harris, considering his neurological approach defend his determinist idea. The conflict that is present in Dennett’s views causes his explanation of the agent being the origin of his action to also be indefensible. Furthermore, due to the incompatibility of the different elements of his view and the vagueness of his idea regarding the effect of unconscious intentions on action, Harris too is placed in a weak position. In contrast to Harris’ supposition, a human is not “a puppet [who] is free as long as he loves his strings”; rather, a human chooses, makes decisions and acts according to his own will. As a result, despite the objections that apply to both philosophers, Dennett’s view is more acceptable than Harris’ in terms of the effort to justify free will; even though neither have been apparently successful in defending their own ideas. (shrink)

Is Rousseau an advocate of natural law or not? The purpose of Rehm’s paper is to suggest a positive answer to this controversially discussed question. On the one hand, Rousseau presents a critical history of traditional natural law theory which in his view is based on flawed suppositions: not upon natural, but on artificial qualities of man, and even rationality and sociability are counted among the latter. On the other hand he presents the self-confident manifesto for a fresh start (...) in natural law theory, founded on what to Rousseau’s mind is the true idea of human nature. The paper intends to show that the only natural qualities which can be seen as anthropological constants are those that keep man flexible, namely perfectibility and freedom of will. It is argued that these are exactly the qualities which according to Rousseau serve as the standard of natural law for the system of politics and its laws: Only a state based upon the free consent of individuals can do justice to man’s perfectibility and freedom of will. Rehm stresses that because of perfectibility and freedom of will, this self-commitment has to be revisable, which is why the republic of the “Social Contract” should not have a constitution, or any law that the citizens cannot alter. It is demonstrated that in Rousseau’s view, this republic is the enabling condition of natural liberty. -/- . (shrink)

The paper shows that it is possible to obtain a "slingshot" result in Gödel's theory of positiveness in the presence of the theorem of the necessary existence of God. In the context of the reconstruction of Gödel's original "slingshot" argument on the suppositions of non-Fregean logic, this is a natural result. The "slingshot" result occurs in sufficiently strong non-Fregean theories accepting the necessary existence of some entities. However, this feature of a Gödelian theory may be considered not as (...) a trivialisation, but as an intended consequence of Gödel's ontotheological views. (shrink)

Due to his significant role in the development of computer technology and the discipline of artificial intelligence, Alan Turing has supposedly subscribed to the theory of mind that has been greatly inspired by the power of the said technology which has eventually become the dominant framework for current researches in artificial intelligence and cognitive science, namely, computationalism or the computational theory of mind. In this essay, I challenge this supposition. In particular, I will try to show that (...) there is no evidence in Turing’s two seminal works that supports such a supposition. His 1936 paper is all about the notion of computation or computability as it applies to mathematical functions and not to the nature or workings of intelligence. On the other hand, while his 1950 work is about intelligence, it is, however, particularly concerned with the problem of whether intelligence can be attributed to computing machines and not of whether computationality can be attributed to human intelligence or to intelligence in general. (shrink)

This article raises two questions about Robert Myers and Claudine Verheggen's terrific book, Donald Davidson's Triangulation Argument: A Philosophical Inquiry. The first question, concerning the first part of the book, is whether, starting from the assumption that a solitary individual cannot have thought contents, we can show that adding another individual to the picture cannot resolve the problem. The second question, concerning the second part, is whether a more sophisticated, decision-theoretic, Humean about the pro-attitudes can respond to the objections to (...) the simple Humean view, and whether Davidson was not in fact just such a sophisticated decision-theoretic Humean. RÉSUMÉ: Cet article pose deux questions sur le formidable livre de Robert Myers et Claudine Verheggen, Donald Davidson's Triangulation Argument: A Philosophical Inquiry. La première question, qui concerne la première partie du livre, consiste à déterminer si, étant donné la supposition qu'un individu solitaire ne peut pas avoir de contenus mentaux, nous pouvons démontrer qu'ajouter un autre individu ne permet pas de résoudre le problème. La seconde question, qui concerne la deuxième partie du livre, est de savoir si un tenant d'une conception humienne des pro-attitudes plus sophistiquée, adhérant à la théorie de la décision, peut répondre aux objections formulées contre la simple conception humienne, et si Davidson n’était pas en fait un tenant de ce second type de conception humienne. (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)

This paper discusses two notational variance views with respect to indexical singular reference and content: the view that certain forms of Millianism are at bottom notational variants of a Fregean theory of reference, the Fregean Notational Variance Claim; and the view that certain forms of Fregeanism are at bottom notational variants of a direct reference theory, the Millian Notational Variance Claim. While the former claim rests on the supposition that a direct reference theory could be easily (...) turned into a particular version of a neo-Fregean one by showing that it is bound to acknowledge certain senselike entities, the latter claim is based upon the supposition that a neo-Fregean theory could be easily turned into a particular version of a Millian one by showing that De Re senses are theoretically superfluous and hence eliminable. The question how many accounts of singular reference and content are we confronted with here — Two different (and mutually antagonistic) theories? Or just two versions of what is in essence the same theory? — is surely of importance to anyone interested in the topic. And this question should be answered by means of a careful assessment of the soundness of each of the above claims. Before trying to adjudicate between the two accounts, one would naturally want to know whether or not there are indeed two substantially disparate accounts. Grosso modo, if the Fregean Claim were sound then we would have a single general conception of singular reference to deal with, viz. Fregeanism; likewise, if the Millian Claim were sound we would be facing a single general conception of singular reference, viz. Millianism. My view is that both the Fregean Notational Variance Claim and its Millian counterpart are wrong, though naturally on different grounds. I have argued elsewhere that the Fregean Notational Variance Claim - considered in its application to the semantics of propositional-attitude reports involving proper names — is unsound. I intend tosupplement in this paper such a result by trying to show that the Millian Claim - taken in its application to the semantics of indexical expressions — should also be rated as incorrect. I focus on a certain set of arguments for the Millian Claim, arguments which I take as adequately representing the general outlook of the Millian theorist with respect to neo-Fregeanism about indexicals and which involve issues about the cognitive significance of sentences containing indexical terms. (shrink)

*This is a project I hope to come back to one day. It stalled, a bit, on the absence of a positive theory of update I could be satisfied with* When should we believe a indicative conditional, and how much confidence in it should we have? Here’s one proposal: one supposes actual the antecedent; and sees under that supposition what credence attaches to the consequent. Thus we suppose that Oswald did not shot Kennedy; and note that under this (...) assumption, Kennedy was assassinated by someone other than Oswald. Thus we are highly confident in the indicative: if Oswald did not kill Kennedy, someone else did. (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)

Many believe that a suitably programmed computer could act for its own goals and experience feelings. I challenge this view and argue that agency, mental causation and qualia are all founded in the unique, homeostatic nature of living matter. The theory was formulated for coherence with the concept of an agent, neuroscientific data and laws of physics. By this method, I infer that a successful action is homeostatic for its agent and can be caused by a feeling - which (...) does not motivate as a force, but as a control signal. From brain research and the locality principle of physics, I surmise that qualia are a fundamental, biological form of energy generated in specialized neurons. Subjectivity is explained as thermodynamically necessary on the supposition that, by converting action potentials to feelings, the neural cells avert damage from the electrochemical pulses. In exchange for this entropic benefit, phenomenal energy is spent as and where it is produced - which precludes the objective observation of qualia. (shrink)