Suppose you are at the gym trying to see some naked beauties by peeping through a hole in the wall. A policeman happens by, he asks you what you are doing, and you honestly tell him. He then arrests you for voyeurism. Are you guilty? We don’t know yet because there is one more fact to be considered: while you honestly thought that a locker room was on the other side of the wall, it was actually a squash court. Are (...) you guilty now? -/- Probably. You might argue that your scopophiliac ambition was impossible to satisfy given that you were peeping into a squash court, not a locker room. But this “Impossibility Defense” would fail because most jurisdictions follow the very influential Model Penal Code (MPC), which says that what is important about attempt is not the likelihood of success but rather what was going on in your head. You tried to peer into a locker room with the intention of seeing some nudity; that is enough for culpability. The fact that you were mistaken about the location does not exonerate you. -/- But now suppose that the particular jurisdiction you are in does not criminalize voyeurism. While most people think that voyeurism is just plain wrong, if not disgusting, the legislature just never got around to drafting a statute against it. Are you guilty now? The answer is no. But you might just be out of luck and convicted anyway. -/- The reason for this strange conclusion is that most jurisdictions have followed the Model Penal Code in yet another respect: along with the MPC’s “subjectivist” emphasis on what is in your head, they have followed the MPC’s lead in abolishing the Impossibility Defense entirely. As a result, people who believe that they are breaking laws when they really are not may still be subject to arrest, prosecution, and conviction respectively by police, prosecutors, and judges/juries merely if all three parties regard your conduct — especially your trying to violate a law that you mistakenly believed in — as morally reprehensible. The best, if not only, defense against this charge is the Impossibility Defense, but — again — most jurisdictions have decided to make this defense unavailable to defendants. -/- Depriving eligible defendants of the Impossibility Defense is unjust. It violates one of the most basic principles of criminal justice: the legality principle. The legality principle says that there cannot be just punishment without a crime, and there should not be a crime without an explicit law designating it as such. So you cannot be charged with, and convicted of, attempted voyeurism if voyeurism, reprehensible as it may be, was not explicitly prohibited at the time that you made the attempt. -/- If we believe in the legality principle, then we must restore the Impossibility Defense. Without the latter, too many defendants are being — and will continue to be — punished for attempts to perform acts that were not themselves illegal but which various parties in the criminal justice system (except the legislature) thought should be illegal based on their extralegal, moral prejudices. -/- In addition to the MPC, the principal obstacle to resurrecting the Impossibility Defense is a good deal of conceptual confusion that permeates relevant cases and scholarship. Too many courts and academics have conflated “factual impossibility” with “legal impossibility” and have fallaciously inferred “hybrid impossibility” from “hybrid mistakes” (that is, legal mistakes that derive from factual mistakes). One of the principal goals of this Article, then, is to clear up all of this confusion. I will explicate in the simplest possible terms (a) the difference between factual impossibility and legal impossibility, (b) why only legal impossibility qualifies as exculpatory, and (c) why hybrid impossibility simply does not exist. (shrink)

Riker (1982) famously argued that Arrow’s impossibility theorem undermined the logical foundations of “populism”, the view that in a democracy, laws and policies ought to express “the will of the people”. In response, his critics have questioned the use of Arrow’s theorem on the grounds that not all configurations of preferences are likely to occur in practice; the critics allege, in particular, that majority preference cycles, whose possibility the theorem exploits, rarely happen. In this essay, I argue that the (...) critics’ rejoinder to Riker misses the mark even if its factual claim about preferences is correct: Arrow’s theorem and related results threaten the populist’s principle of democratic legitimacy even if majority preference cycles never occur. In this particular context, the assumption of an unrestricted domain is justified irrespective of the preferences citizens are likely to have. (shrink)

This article examines the effect of material evidence upon historiographic hypotheses. Through a series of successive Bayesian conditionalizations, I analyze the extended competition among several hypotheses that offered different accounts of the transition between the Bronze Age and the Iron Age in Palestine and in particular to the “emergence of Israel”. The model reconstructs, with low sensitivity to initial assumptions, the actual outcomes including a complete alteration of the scientific consensus. Several known issues of Bayesian confirmation, including the problem of (...) old evidence, the introduction and confirmation of novel theories and the sensitivity of convergence to uncertain and disputed evidence are discussed in relation to the model’s result and the actual historical process. The most important result is that convergence of probabilities and of scientific opinion is indeed possible when advocates of rival hypotheses hold similar judgment about the factual content of evidence, even if they differ sharply in their historiographic interpretation. This speaks against the contention that understanding of present remains is so irrevocably biased by theoretical and cultural presumptions as to make an objective assessment impossible. (shrink)

Nearly thirty years ago, Robert Alexy in his book The Concept and Validity of Law as well as in other early articles raised non-positivistic arguments in the Continental European tradition against legal positivism in general, which was assumed to be held by, among others, John Austin, Hans Kelsen and H.L.A. Hart. The core thesis of legal positivism that was being discussed among contemporary German jurists, just as with their Anglo- American counterparts, is the claim that there is no necessary connection (...) between law and morality. Robert Alexy has argued, however, that the law, besides consisting conceptually of elements of authoritative issuance and social efficacy, necessarily lays a claim to substantial correctness, which is derived from analytical arguments. Furthermore, if this claim to substantial correctness necessarily requires the incorporation of moral elements into law, then the ‘necessary connection thesis’, as defended by non-positivism, can be justified. Some of the most significant objections to this sort of claim, stemming from the Anglo-American world, are those introduced by Joseph Raz. In his ‘Reply’ to Robert Alexy, Raz raises at least three interesting criticisms, including, first, the ambiguity of ‘legal theory in the positivistic tradition’, second, the indeterminate formulations of the ‘separation thesis’, and, third, the necessary claim of law to legitimate authority as a moral claim. As a point of departure, I will argue that Raz’s three criticisms are misleading. For they do not enhance our understanding of the genuine compatibility or incompatibility between legal positivism and non-positivism. Despite the frequently reformulated theses of legal positivism and the various kinds of opponents responding thereto, the essential divergence between legal positivism and non-positivism was and remains the answer to the question of the relation between law and morality. Furthermore, I will clarify that in the strictest sense there can be three and only three logically possible positions concerning the relation between law and morality: the connection between them is either necessary, or impossible (i. e. they are necessarily separate), or contingent (i. e. they are neither necessarily connected nor necessarily separate). The first position is non-positivistic, while the latter two positions are, indeed, both positivistic, but in different forms: one may be called ‘exclusive’ legal positivism, the other ‘inclusive’ legal positivism. I will continue by showing that these three positions stand to one another in the relation of contraries, not contradictories, and that, taken together, they exhaust the logically possible positions concerning the relation between law and morality, never mind the tradition or authority from which these positions are derived. Raz mentions, however, many changeable formulations of the separation thesis, which even leads him to acknowledge ‘necessary connections between law and morality’. One who is trying to understand legal positivism would no doubt be puzzled by this claim. Nevertheless, I will argue that this is an alternative strategy of legal positivism, and it points to naturalistically oriented view. Although this necessary separation between law and morality, understood naturalistically, strikes one as strengthening the separation, in the end it leads to a weakened notion of necessity. This weakened necessary separation thesis, however, cannot be justified through the so-called claim of the law to legitimate authority, defended by Raz, for it is difficult to answer the question of whether a normally justified but factual authority can gain legitimate authority. Finally, the necessary connection between law and morality in a strong sense can still be justified by the claim of law to correctness, as per Alexy’s argument. (shrink)

The objective of this work is to present Ludwig Wittgenstein's perspective on the impossibility of the existence of philosophical problems, to then reflect on the implications of such a perspective based on Popper's thought. For that, Wittgenstein's perspective, as exposed in his work Tractatus logico-philosophicus, is contrasted with Karl Popper's perspective presented in “The nature of philosophical problems and their scientific roots” (in Conjectures and refutations). The example of the problem faced by Kant in his work Critique of pure (...) reason will also be considered for the analysis of Wittgenstein's argument. According to Wittgenstein, philosophical problems are pseudo-problems because they have no solution. However, despite admitting the existence of pseudo-problems, Popper argues that factual, logical, or hybrid problems, under certain circumstances, can be philosophical. Thus, the aim is to contrast these two perspectives in order to emphasize how not all philosophical problems are pseudo-problems. (shrink)

The debate concerning the proper way of understanding, and hence solving, the “is-ought problem” produced two mutually exclusive positions. One position claims that it is entirely impossible to deduce an imperative statement from a set of factual statements. The other position holds a contrary view to the effect that one can naturally derive an imperative statement from a set of factual statements under certain conditions. Although these two positions have opposing views concerning the problem, it should be evident (...) that they both accept that the “is-ought problem” is concerned with the deducibility of imperative statements from factual statements. Later I will argue that this should not be our concern when we try to make sense of the way we reason about morality. (shrink)

Let us start by some general definitions of the concept of complexity. We take a complex system to be one composed by a large number of parts, and whose properties are not fully explained by an understanding of its components parts. Studies of complex systems recognized the importance of “wholeness”, defined as problems of organization (and of regulation), phenomena non resolvable into local events, dynamics interactions in the difference of behaviour of parts when isolated or in higher configuration, etc., in (...) short, systems of various orders (or levels) not understandable by investigation of their respective parts in isolation. In a complex system it is essential to distinguish between ‘global’ and ‘local’ properties. Theoretical physicists in the last two decades have discovered that the collective behaviour of a macro-system, i.e. a system composed of many objects, does not change qualitatively when the behaviour of single components are modified slightly. Conversely, it has been also found that the behaviour of single components does change when the overall behaviour of the system is modified. There are many universal classes which describe the collective behaviour of the system, and each class has its own characteristics; the universal classes do not change when we perturb the system. The most interesting and rewarding work consists in finding these universal classes and in spelling out their properties. This conception has been followed in studies done in the last twenty years on second order phase transitions. The objective, which has been mostly achieved, was to classify all possible types of phase transitions in different universality classes and to compute the parameters that control the behaviour of the system near the transition (or critical or bifurcation) point as a function of the universality class. This point of view is not very different from the one expressed by Thom in the introduction of Structural Stability and Morphogenesis (1975). It differs from Thom’s program because there is no a priori idea of the mathematical framework which should be used. Indeed Thom considers only a restricted class of models (ordinary differential equations in low dimensional spaces) while we do not have any prejudice regarding which models should be accepted. One of the most interesting and surprising results obtained by studying complex systems is the possibility of classifying the configurations of the system taxonomically. It is well-known that a well founded taxonomy is possible only if the objects we want to classify have some unique properties, i.e. species may be introduced in an objective way only if it is impossible to go continuously from one specie to another; in a more mathematical language, we say that objects must have the property of ultrametricity. More precisely, it was discovered that there are conditions under which a class of complex systems may only exist in configurations that have the ultrametricity property and consequently they can be classified in a hierarchical way. Indeed, it has been found that only this ultrametricity property is shared by the near-optimal solutions of many optimization problems of complex functions, i.e. corrugated landscapes in Kauffman’s language. These results are derived from the study of spin glass model, but they have wider implications. It is possible that the kind of structures that arise in these cases is present in many other apparently unrelated problems. Before to go on with our considerations, we have to pick in mind two main complementary ideas about complexity. (i) According to the prevalent and usual point of view, the essence of complex systems lies in the emergence of complex structures from the non-linear interaction of many simple elements that obey simple rules. Typically, these rules consist of 0–1 alternatives selected in response to the input received, as in many prototypes like cellular automata, Boolean networks, spin systems, etc. Quite intricate patterns and structures can occur in such systems. However, what can be also said is that these are toy systems, and the systems occurring in reality rather consist of elements that individually are quite complex themselves. (ii) So, this bring a new aspect that seems essential and indispensable to the emergence and functioning of complex systems, namely the coordination of individual agents or elements that themselves are complex at their own scale of operation. This coordination dramatically reduces the degree of freedom of those participating agents. Even the constituents of molecules, i.e. the atoms, are rather complicated conglomerations of subatomic particles, perhaps ultimately excitations of patterns of superstrings. Genes, the elementary biochemical coding units, are very complex macromolecular strings, as are the metabolic units, the proteins. Neurons, the basic elements of cognitive networks, themselves are cells. In those mentioned and in other complex systems, it is an important feature that the potential complexity of the behaviour of the individual agents gets dramatically simplified through the global interactions within the system. The individual degrees of freedom are drastically reduced, or, in a more formal terminology, the factual space of the system is much smaller than the product of the state space of the individual elements. That is one key aspect. The other one is that on this basis, that is utilizing the coordination between the activities of its members, the system then becomes able to develop and express a coherent structure at a higher level, that is, an emergent behaviour (and emergent properties) that transcends what each element is individually capable of. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Literature 25.2 (2001) 215-232 [Access article in PDF] Eighteenth-Century Print Culture and the "Truth" of Fictional Narrative Lisa Zunshine As a session entitled "Truth" at a recent Modern Language Association of America annual convention has demonstrated, the obsession with the epistemologies of truth is alive and well. Our "familiar ways of thinking and talking about truth," as one of the speakers, Barbara Herrnstein Smith, observed, remain "theoretically (...) elusive, discursively slippery, and hard or perhaps impossible to articulate clearly in relation to other current concepts and ideas" 1 --an irresistible invitation to further thinking and talking on the subject. My essay enters this conversation by attempting to contemplate truth not as a stable attribute but as a ongoing attribution, that is, not as an inherent property but rather as a dynamic process predicated upon functional idiosyncrasies of our evolved cognitive architecture. The broad question posed here is this: What if our never-ending quest for truth is itself cognitively constructed and the various forms that this quest takes manifest the (not necessarily harmonious) interaction between our evolved cognitive capacities and the ever-changing specifics of our cultural environment?Consider just one of the forms of such an interaction, namely, our age-long preoccupation with the "truth" of literary narrative. In many respects, this preoccupation is counterproductive: the most "fantastic" story contains a number of contingently useful "truths" about the world, whereas the most "factual" narrative manipulates facts by virtue of being a narrative or a subjective arrangementof information. Still, we persevere in wanting to put the label "fiction" or "nonfiction" onto any story that comes our way. As I will argue, the bookstore's organization of its sections satisfies this species of "cognitive" craving as well as [End Page 215] reinforces it, making it seem culturally inevitable. Viewed from this perspective, our culture appears to be a multifaceted feedback mechanism engaged in the process of satisfying, reinforcing, struggling with, and manipulating our cognitive predispositions.The cultural manipulation of our cognitive predispositions is the topic of the present essay, which discusses several examples of such manipulation that respond to our desire to assign a certain "truth-value" to a given narrative, i.e., to attach a label to it announcing its "factuality" or "fictionality." "Truth-value" is a loaded term, resisting definition, and liable to lead me into trouble. Imperfect as it is, however, I need it in order to shuffle between two scholarly discourses that do not (yet) have much vocabulary in common: literary criticism and cognitive science. The reason for turning to cognitive science in my discussion of literary narrative is that cognitive anthropologists and psychologists frequently engage the same problems that we do when we ask, What is "Fiction"? How is it different from "History"? How do we decide whether what we are reading is "true?" The key difference between the two approaches is, however, that whereas the literary critic focuses on specific texts produced and read in specific cultural circumstances, the cognitive anthropologist pays attention to the cross-cultural insistence with which people wish to and often claim to distinguish "truth" from "fiction" and inquires into the possible evolutionary history of the cognitive architecture implicated in our never-ending quest for "truth." The latter perspective can thus be useful for literary studies because, by suggesting that our evolved cognitive architecture often "encourages" us to construe the world as a negotiation of "truths" and "nontruths," this perspective begins to account--at least on some level--for the fact that people may approach a complex cultural artifact, such as a novel, with a "truth"/"non-truth" binary in mind that is ultimately not very productive. 2 Evolutionary psychologists and anthropologists frequently point to disjunctions between the tasks that our brain evolved to solve and the tasks that we have to deal with in the modern environment; our vexed insistence on determining the truth-value of the 500-page printed narrative--not an object one would come across in the Pleistocene--can be seen as yet another instance of such a disjunction.Thus, I suggest that, on the... (shrink)

This article maintains that the so-called theory-practice divide in legal education is not only factually false but semantically impossible. -/- As to the divide's falsity, practitioners have of course performed excellent scholarship and academics have excelled in practice. As to the divide's semantic impossibility, this article examines, among other things: -/- (1) the essential role of experience in meaning, -/- (2) the resulting inseparability of theory and practice in the world of experience, -/- (3) problems the divide shares in (...) common with debunked Cartesian dualism, and -/- (4) modern cognitive psychology’s notions of embodied meaning which further underscore the semantic impossibility of separating theory from practice in the world of experience. -/- Using insights from such examinations, this article also explores implications of a debunked theory-practice divide for, among other things, law school curriculums and law school faculty hiring standards. -/- Keywords: legal education, legal writing, semantics, theory, practice, experience, Charles Sanders Peirce, embodied meaning, cognitive psychology, Cartesian dualism, affordance knowledge, metaphor, George Lakoff, category, humanities, Langdell, pragmatism, semiotics, philosophy. (shrink)

The possibility of testing contradictory statements about the factual world has been suggested but barely discussed in the relevant literature. Here I argue that if we assume that there are contradictory observation sentences, it would be logically impossible to falsify them. Accordingly, the extension of the dialetheist programme into empirical science would be non-advisable, for it would introduce logically unfalsifiable claims.

This paper explains a fallacy that often arises in theorizing about human minds. I call it the Factual Belief Fallacy. The Fallacy, roughly, involves drawing conclusions about human psychology that improperly ignore the large backgrounds of mostly accurate factual beliefs people have. The Factual Belief Fallacy has led to significant mistakes in both philosophy of mind and cognitive science of religion. Avoiding it helps us better see the difference between factual belief and religious credence; seeing that (...) difference in turn enables us to pose interesting normative questions about various mental states labeled “belief.”. (shrink)

Impossible worlds are representations of impossible things and impossible happenings. They earn their keep in a semantic or metaphysical theory if they do the right theoretical work for us. As it happens, a worlds-based account provides the best philosophical story about semantic content, knowledge and belief states, cognitive significance and cognitive information, and informative deductive reasoning. A worlds-based story may also provide the best semantics for counterfactuals. But to function well, all these accounts need use of impossible and as well (...) as possible worlds. So what are impossible worlds? Graham Priest claims that any of the usual stories about possible worlds can be told about impossible worlds, too. But far from it. I'll argue that impossible worlds cannot be genuine worlds, of the kind proposed by Lewis, McDaniel or Yagisawa. Nor can they be ersatz worlds on the model proposed by Melia or Sider. Constructing impossible worlds, it turns out, requires novel metaphysical resources. (shrink)

What does it mean for the laws of logic to fail? My task in this paper is to answer this question. I use the resources that Routley/Sylvan developed with his collaborators for the semantics of relevant logics to explain a world where the laws of logic fail. I claim that the non-normal worlds that Routley/Sylvan introduced are exactly such worlds. To disambiguate different kinds of impossible worlds, I call such worlds logically impossible worlds. At a logically impossible world, the laws (...) of logic fail. In this paper, I provide a definition of logically impossible worlds. I then show that there is nothing strange about admitting such worlds. (shrink)

What are the truth conditions of want ascriptions? According to an influential approach, they are intimately connected to the agent’s beliefs: ⌜S wants p⌝ is true iff, within S’s belief set, S prefers the p worlds to the not-p worlds. This approach faces a well-known problem, however: it makes the wrong predictions for what we call (counter)factual want ascriptions, wherein the agent either believes p or believes not-p—for example, ‘I want it to rain tomorrow and that is exactly what (...) is going to happen’ or ‘I want this weekend to last forever, but of course it will end in a few hours’. We solve this problem. The truth conditions for want ascriptions are, we propose, connected to the agent’s conditional beliefs. We substantiate this connection by pursuing a striking parallel between (counter)factual and non-(counter)factual want ascriptions on the one hand and counterfactual and indicative conditionals on the other. (shrink)

Philosophers are divided on whether it is possible to intend believed-impossible outcomes. Several thought experiments in the action theory literature suggest that this is conceptually possible, though they have not been tested in ordinary social cognition. We conducted three experiments to determine whether, on the ordinary view, it is conceptually possible to intend believed-impossible outcomes. Our findings indicate that participants firmly countenance the possibility of intending believed-impossible outcomes, suggesting that it is conceptually possible to intend to do something that one (...) believes is impossible. (shrink)

I want to model a finite, fallible cognitive agent who imagines that p in the sense of mentally representing a scenario—a configuration of objects and properties—correctly described by p. I propose to capture imagination, so understood, via variably strict world quantifiers, in a modal framework including both possible and so-called impossible worlds. The latter secure lack of classical logical closure for the relevant mental states, while the variability of strictness captures how the agent imports information from actuality in the imagined (...) non-actual scenarios. Imagination turns out to be highly hyperintensional, but not logically anarchic. Section 1 sets the stage and impossible worlds are quickly introduced in Sect. 2. Section 3 proposes to model imagination via variably strict world quantifiers. Section 4 introduces the formal semantics. Section 5 argues that imagination has a minimal mereological structure validating some logical inferences. Section 6 deals with how imagination under-determines the represented contents. Section 7 proposes additional constraints on the semantics, validating further inferences. Section 8 describes some welcome invalidities. Section 9 examines the effects of importing false beliefs into the imagined scenarios. Finally, Sect. 10 hints at possible developments of the theory in the direction of two-dimensional semantics. (shrink)

In this paper, we argue that a distinction ought to be drawn between two ways in which a given world might be logically impossible. First, a world w might be impossible because the laws that hold at w are different from those that hold at some other world (say the actual world). Second, a world w might be impossible because the laws of logic that hold in some world (say the actual world) are violated at w. We develop a novel (...) way of modelling logical possibility that makes room for both kinds of logical impossibility. Doing so has interesting implications for the relationship between logical possibility and other kinds of possibility (for example, metaphysical possibility) and implications for the necessity or contingency of the laws of logic. (shrink)

Accounts of propositions as sets of possible worlds have been criticized for conflating distinct impossible propositions. In response to this problem, some have proposed to introduce impossible worlds to represent distinct impossibilities, endorsing the thesis that impossible worlds must be of the same kind; this has been called the parity thesis. I show that this thesis faces problems, and propose a hybrid account which rejects it: possible worlds are taken as concrete Lewisian worlds, and impossibilities are represented as set-theoretic constructions (...) out of them. This hybrid account (1) distinguishes many intuitively distinct impossible propositions; (2) identifies impossible propositions with extensional constructions; (3) avoids resorting to primitive modality, at least so far as Lewisian modal realism does. (shrink)

In this paper, I investigate whether we can use a world-involving framework to model the epistemic states of non-ideal agents. The standard possible-world framework falters in this respect because of a commitment to logical omniscience. A familiar attempt to overcome this problem centers around the use of impossible worlds where the truths of logic can be false. As we shall see, if we admit impossible worlds where “anything goes” in modal space, it is easy to model extremely non-ideal agents that (...) are incapable of performing even the most elementary logical deductions. A much harder, and considerably less investigated challenge is to ensure that the resulting modal space can also be used to model moderately ideal agents that are not logically omniscient but nevertheless logically competent. Intuitively, while such agents may fail to rule out subtly impossible worlds that verify complex logical falsehoods, they are nevertheless able to rule out blatantly impossible worlds that verify obvious logical falsehoods. To model moderately ideal agents, I argue, the job is to construct a modal space that contains only possible and non-trivially impossible worlds where it is not the case that “anything goes”. But I prove that it is impossible to develop an impossible-world framework that can do this job and that satisfies certain standard conditions. Effectively, I show that attempts to model moderately ideal agents in a world-involving framework collapse to modeling either logical omniscient agents, or extremely non-ideal agents. (shrink)

This paper gives a framework for understanding causal counterpossibles, counterfactuals imbued with causal content whose antecedents appeal to metaphysically impossible worlds. Such statements are generated by omissive causal claims that appeal to metaphysically impossible events, such as “If the mathematician had not failed to prove that 2+2=5, the math textbooks would not have remained intact.” After providing an account of impossible omissions, the paper argues for three claims: (i) impossible omissions play a causal role in the actual world, (ii) causal (...) counterpossibles have broad applications in philosophy, and (iii) the truth of causal counterpossibles provides evidence for the nonvacuity of counterpossibles more generally. (shrink)

A thesis (“weak BCP”) nearly universally held among philosophers of probability connects the concepts of objective chance and metaphysical modality: Any prospect (outcome) that has a positive chance of obtaining is metaphysically possible—(nearly) equivalently, any metaphysically impossible prospect has zero chance. Particular counterexamples are provided utilizing the monotonicity of chance, one of them related to the four world paradox. Explanations are offered for the persistent feeling that there cannot be chancy metaphysical necessities or chancy metaphysical impossibilities. Chance is objective but (...) contrary to popular opinion it is also largely epistemic. Chancy necessities are analogous to necessary a posteriori truths. Philosophy and Phenomenological Research, Volume 99, Issue 3, Page 644-662, November 2019. (shrink)

Arrhenius’s impossibility theorems purport to demonstrate that no population axiology can satisfy each of a small number of intuitively compelling adequacy conditions. However, it has recently been pointed out that each theorem depends on a dubious assumption: Finite Fine-Grainedness. This assumption states that there exists a finite sequence of slight welfare differences between any two welfare levels. Denying Finite Fine-Grainedness makes room for a lexical population axiology which satisfies all of the compelling adequacy conditions in each theorem. Therefore, Arrhenius’s (...) theorems fail to prove that there is no satisfactory population axiology. In this paper, I argue that Arrhenius’s theorems can be repurposed. Since all of our population-affecting actions have a non-zero probability of bringing about more than one distinct population, it is population prospect axiologies that are of practical relevance, and amended versions of Arrhenius’s theorems demonstrate that there is no satisfactory population prospect axiology. These impossibility theorems do not depend on Finite Fine-Grainedness, so lexical views do not escape them. (shrink)

Impossible fictions are valuable evidence both for a theory of fiction and for theories of meaning, mind and epistemology. This article focuses on what we can learn about fiction from reflecting on impossible fictions. First, different kinds of impossible fiction are considered, and the question of how much fiction is impossible is addressed. What impossible fiction contributes to our understanding of "truth in fiction" and the logic of fiction will be examined. Finally, our understanding of unreliable narrators and unreliable narration (...) in fiction needs to accommodate stories that, on the face of it, cannot possibly be true. (shrink)

“There is no use in trying,” said Alice; “one can’t believe impossible things.” “I dare say you haven’t had much practice,” said the Queen. “When I was your age, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast”. Lewis Carroll, Through the Looking Glass. -/- It is a rather common view among philosophers that one cannot, properly speaking, be said to believe, conceive, imagine, hope for, or seek (...) what is impossible. -/- Some philosophers, for instance George Berkeley and the early Wittgenstein, thought that logically contradictory propositions lack cognitive meaning (informational content) and cannot, therefore, be thought or believed. Philosophers who do not go as far as Berkeley and Wittgenstein in denying that impossible propositions or states of affairs are thinkable, may still claim that it is impossible to rationally believe an impossible proposition. On a classical “Cartesian” view of belief, belief is a purely mental state of the agent holding true a proposition p that she “grasps” and is directly acquainted with. But if the agent is directly acquainted with an impossible proposition, then, presumably, she must know that it is impossible. But surely no rational agent can hold true a proposition that she knows is impossible. Hence, no rational agent can believe an impossible proposition. Thus it seems that on the Cartesian view of propositional attitudes as inner mental states in which proposition are immediately apprehended by the mind, it is impossible for a rational agent to believe, imagine or conceive an impossible proposition. -/- Ruth Barcan Marcus (1983) has suggested that a belief attribution is defeated once it is discovered that the proposition, or state of affairs that is believed is impossible. According to her intuition, just as knowledge implies truth, belief implies possibility. -/- It is commonplace that people claim to believe propositions that later turn out to be impossible. According to Barcan Marcus, the correct thing to say in such a situation is not: I once believed that A but I don’t believe it any longer since I have come to realize that it is impossible that A. What one should say is instead: It once appeared to me that I believed that A, but I did not, since it is impossible that A. Thus, Barcan Marcus defends what we might call Alice’s thesis: Necessarily, for any proposition p and any subject x, if x believes p, then p is possible. -/- Alice’s thesis that it is impossible to hold impossible beliefs, seems to come into conflict with our ordinary practices of attributing beliefs. Consider a mathematical example. Some mathematicians believe that CH (the continuum hypothesis) is true and others believe that it is false. But if CH is true, then it is necessarily true; and if it is false, then it is necessarily false. Regardless of whether CH is true or false, the conclusion seems to be that there are mathematicians who believe impossible propositions. -/- Examples of apparent beliefs in impossible propositions outside of mathematics are also easy to come by. Consider, for example, Kripke’s (1999) story of the Frenchman Pierre who without realizing it has two different names ‘London’ and ‘Londres’ for the same city, London. After having arrived in London, Pierre may assent to ‘Londres is beautiful and London is not beautiful’ without being in any way irrational. It seems reasonably to infer from this that Pierre believes that Londres is beautiful and London is not beautiful. But since ‘Londres’ and ‘London’ are rigid designators for the same city, it seems to follow from this that Pierre believes the inconsistent proposition that we may express as ‘London is both beautiful and not beautiful’. (shrink)

Possible worlds have found many applications in contemporary philosophy: from theories of possibility and necessity, to accounts of conditionals, to theories of mental and linguistic content, to understanding supervenience relationships, to theories of properties and propositions, among many other applications. Almost as soon as possible worlds started to be used in formal theories in logic, philosophy of language, philosophy of mind, metaphysics, and elsewhere, theorists started to wonder whether impossible worlds should be postulated as well. In many applications, possible worlds (...) face limitations that can be dealt with through postulating impossible worlds as well. This chapter examines some of the uses of impossible worlds, and philosophical challenges theories of impossible worlds face. (shrink)

Within debates concerning responsibility for ignorance the distinction between moral and factual ignorance is often treated as crucial. Many prominent accounts hold that while factual ignorance routinely exculpates, moral ignorance never does so. The view that there is an in-principle distinction between moral and factual ignorance has been referred to as the “Asymmetry Thesis.” This view stands in opposition to the “Parity Thesis,” which holds that moral and factual ignorance are in-principle similar. The Parity Thesis has (...) been closely aligned with volitionist accounts of moral responsibility, whereas the Asymmetry Thesis has been closely aligned with Quality of Will accounts. Two central questions are at work here: how ignorance excuses, and whether it excuses in the same way for both moral and factual ignorance. I will argue that these questions have often been confused in the present debate, and once we have distinguished more clearly between them, it seems that Quality of Will accounts are compatible with the Parity Thesis. And more generally: that the distinction between moral and factual ignorance is far less important in debates about responsibility for ignorance than it has often appeared. (shrink)

Theories of content are at the centre of philosophical semantics. The most successful general theory of content takes contents to be sets of possible worlds. But such contents are very coarse-grained, for they cannot distinguish between logically equivalent contents. They draw intensional but not hyperintensional distinctions. This is often remedied by including impossible as well as possible worlds in the theory of content. Yet it is often claimed that impossible worlds are metaphysically obscure; and it is sometimes claimed that their (...) use results in a trivial theory of content. In this paper, I set out the need for impossible worlds in a theory of content; I briefly sketch a metaphysical account of their nature; I argue that worlds in general must be very fine-grained entities; and, finally, I argue that the resulting conception of impossible worlds is not a trivial one. (shrink)

In this paper, I discuss two different metaethical challenges based on population ethical impossibility results. According to the anti‐realist challenge, the results pose a serious threat to the existence of objective moral facts. According to the skeptical challenge, the results pose a serious threat to the reliability of our moral intuitions. My aim is to systematically explore and evaluate these challenges. In addition to clarifying the issues, I argue that population ethical impossibility results do not in fact support (...) any anti‐realist or skeptical conclusions. (shrink)

Lewisian Genuine Realism about possible worlds is often deemed unable to accommodate impossible worlds and reap the benefits that these bestow to rival theories. This thesis explores two alternative extensions of GR into the terrain of impossible worlds. It is divided in six chapters. Chapter I outlines Lewis’ theory, the motivations for impossible worlds, and the central problem that such worlds present for GR: How can GR even understand the notion of an impossible world, given Lewis’ reductive theoretical framework? Since (...) the desideratum is to incorporate impossible worlds into GR without compromising Lewis’ reductive analysis of modality, Chapter II defends that analysis against objections. The rest of the thesis is devoted to incorporating impossible worlds into GR. Chapter III explores GR-friendly impossible worlds in the form of set-theoretic constructions out of genuine possibilia. Then, Chapters IV-VI venture into concrete impossible worlds. Chapter IV addresses Lewis’ objection against such worlds, to the effect that contradictions true at impossible worlds amount to true contradictions tout court. I argue that even if so, the relevant contradictions are only ever about the non-actual, and that Lewis’ argument relies on a premise that cannot be nonquestion- beggingly upheld in the face of genuine impossible worlds in any case. Chapter V proposes that Lewis’ reductive analysis can be preserved, even in the face of genuine impossibilia, if we differentiate the impossible from the possible by means of accessibility relations, understood non-modally in terms of similarity. Finally, Chapter VI counters objections to the effect that there are certain impossibilities, formulated in Lewis’ theoretical language, which genuine impossibilia should, but cannot, represent. I conclude that Genuine Realism is still very much in the running when the discussion turns to impossible worlds. (shrink)

Standard impossibility theorems on judgment aggregation over logically connected propositions either use a controversial systematicity condition or apply only to agendas of propositions with rich logical connections. Are there any serious impossibilities without these restrictions? We prove an impossibility theorem without requiring systematicity that applies to most standard agendas: Every judgment aggregation function (with rational inputs and outputs) satisfying a condition called unbiasedness is dictatorial (or effectively dictatorial if we remove one of the agenda conditions). Our agenda conditions (...) are tight. When applied illustratively to (strict) preference aggregation represented in our model, the result implies that every unbiased social welfare function with universal domain is effectively dictatorial. (shrink)

One response to the problem of logical omniscience in standard possible worlds models of belief is to extend the space of worlds so as to include impossible worlds. It is natural to think that essentially the same strategy can be applied to probabilistic models of partial belief, for which parallel problems also arise. In this paper, I note a difficulty with the inclusion of impossible worlds into probabilistic models. Under weak assumptions about the space of worlds, most of the propositions (...) which can be constructed from possible and impossible worlds are in an important sense inexpressible; leaving the probabilistic model committed to saying that agents in general have at least as many attitudes towards inexpressible propositions as they do towards expressible propositions. If it is reasonable to think that our attitudes are generally expressible, then a model with such commitments looks problematic. (shrink)

I argue that psychology and epistemology should posit distinct cognitive attitudes of religious credence and factual belief, which have different etiologies and different cognitive and behavioral effects. I support this claim by presenting a range of empirical evidence that religious cognitive attitudes tend to lack properties characteristic of factual belief, just as attitudes like hypothesis, fictional imagining, and assumption for the sake of argument generally lack such properties. Furthermore, religious credences have distinctive properties of their own. To summarize: (...) factual beliefs are practical setting independent, cognitively govern other attitudes, and are evidentially vulnerable. By way of contrast, religious credences have perceived normative orientation, are susceptible to free elaboration, and are vulnerable to special authority. This theory provides a framework for future research in the epistemology and psychology of religious credence. (shrink)

Provides an overview and examples of what impossible figures are, and explains their interest to many different disciplines including philosophy, psychology, art and mathematics.

In their Why Machines Will Never Rule the World, Landgrebe and Smith (2023) argue that it is impossible for artificial general intelligence (AGI) to succeed, on the grounds that it is impossible to perfectly model or emulate the “complex” “human neurocognitive system”. However, they do not show that it is logically impossible; they only show that it is practically impossible using current mathematical techniques. Nor do they prove that there could not be any other kinds of theories than those in (...) current use. Even if perfect theories were impossible or unlikely, perfection may not be needed and may even be unhelpful. (shrink)

The aim of the present article is to investigate the tenability of the principle of compositionality within an impossible worlds framework. To understand how this question is raised, the first section will be devoted to explaining what the principle of compositionality is and how it is compatile with a possible worlds semantics. In the following section, some arguments from hyperintentionality will be provided against such semantics. The third section will introduce the notion of impossible worlds as adequate tools to accommodate (...) such arguments, with particular attention to Berto and Jago’s account (2019). In the fourth section a solution to the compositionality objection towards an impossible worlds semantics will be presented. Finally, the paper will conclude with a possile objection towards such solution. (shrink)

The theory of possible worlds has permeated analytic philosophy in recent decades, and its best versions have a consequence which has gone largely unnoticed: in addition to the panoply of possible worlds, there are a great many impossible worlds. A uniform ontological method alone should bring the friends of possible worlds to adopt impossible worlds, I argue, but the theory's applications also provide strong incentives. In particular, the theory facilitates an account of counterfactuals which avoids several of the implausible results (...) of David Lewis's account, and it paves the way for the analogues of Kripkean semantics for epistemic and relevant logics. On the theories of possible worlds as abstract objects, worlds bear a strong resemblance to propositions. I contend that if there are distinct necessarily false propositions, then there are likewise distinct impossible worlds. However, one who regards possible worlds as concrete objects must not recognize impossible worlds, in part because concrete worlds cannot misrepresent certain features of reality, as some impossible worlds must. Accordingly, I defend and develop a theory of impossible worlds as maximal impossible states of affairs. Impossible worlds perform admirably in the analysis of counterfactuals with impossible antecedents. I argue that, contrary to standard accounts, not all counterpossibles are trivially true, and I develop a Lewis-style semantics which allows this result. The point is crucial, since many views presuppose that some counterpossibles are substantive philosophical truths. Finally, I show that impossible worlds hold great promise for doxastic and relevant logics. Epistemic logic needs a domain of propositions which is not closed under strict implication to avoid the problem of logical omniscience, and relevant logic needs such a domain to avoid the famous paradoxes of implication. In sum, impossible world theory promises natural, elegant solutions to philosophical problems in numerous areas where possible worlds alone flounder. These solutions come to most possible world theorists at no cost, since the existence of impossible worlds is entailed by theses they already hold. (shrink)

There is a theorem that shows that it is impossible for an algorithm to jointly satisfy the statistical fairness criteria of Calibration and Equalised Odds non-trivially. But what about the recently advocated alternative to Calibration, Base Rate Tracking? Here, we show that Base Rate Tracking is strictly weaker than Calibration, and then take up the question of whether it is possible to jointly satisfy Base Rate Tracking and Equalised Odds in non-trivial scenarios. We show that it is not, thereby establishing (...) an even more general impossibility theorem. (shrink)

We present a theory of truth in fiction that improves on Lewis's [1978] ‘Analysis 2’ in two ways. First, we expand Lewis's possible worlds apparatus by adding non-normal or impossible worlds. Second, we model truth in fiction as belief revision via ideas from dynamic epistemic logic. We explain the major objections raised against Lewis's original view and show that our theory overcomes them.

Book Review of Impossible Worlds, by Francesco Berto and Mark Jago. Oxford: Oxford University Press, 2019.

Jack Spencer has recently argued for the striking thesis that, possibly, an agent is able to do the impossible—that is, perform an action that is metaphysically impossible for that person to perform. Spencer bases his argument on (Simple G), a case in which it is impossible for an agent G to perform some action but, according to Spencer, G is still intuitively able to perform that action. I reply that we would have to give up at least four action-theoretical principles (...) if we accept that G is able to do the impossible. We may be best off retaining the principles and thus rejecting Spencer's intuition that G is able to do the impossible. I then consider an argument for the claim that G is able to do the impossible that goes through the Snapshot Principle. I, however, deny that any true variant of the Snapshot Principle shows that G is able to do the impossible. Moreover, the counterexample to the Snapshot Principle that I develop also suggests that G is unable to do the impossible in (Simple G). The most natural explanation for why an agent is unable to perform some action in this counterexample extends to (Simple G). Next, I develop three error theories for why we might initially share Spencer's intuition that G is able to do the impossible in (Simple G). Finally, I consider a couple other "G-cases" of Spencer's and find them all wanting. Perhaps we are unable to do the impossible. (shrink)

Modal knowledge accounts that are based on standards possible-worlds semantics face well-known problems when it comes to knowledge of necessities. Beliefs in necessities are trivially sensitive and safe and, therefore, trivially constitute knowledge according to these accounts. In this paper, I will first argue that existing solutions to this necessity problem, which accept standard possible-worlds semantics, are unsatisfactory. In order to solve the necessity problem, I will utilize an unorthodox account of counterfactuals, as proposed by Nolan, on which we also (...) consider impossible worlds. Nolan’s account for counterpossibles delivers the intuitively correct result for sensitivity i.e. S’s belief is sensitive in intuitive cases of knowledge of necessities and insensitive in intuitive cases of knowledge failure. However, we acquire the same plausible result for safety only if we reject his strangeness of impossibility condition and accept the modal closeness of impossible worlds. In this case, the necessity problem can be analogously solved for sensitivity and safety. For some, such non-moderate accounts might come at too high a cost. In this respect, sensitivity is better off than safety when it comes to knowing necessities. (shrink)

Amalgamating evidence of different kinds for the same hypothesis into an overall confirmation is analogous, I argue, to amalgamating individuals’ preferences into a group preference. The latter faces well-known impossibility theorems, most famously “Arrow’s Theorem”. Once the analogy between amalgamating evidence and amalgamating preferences is tight, it is obvious that amalgamating evidence might face a theorem similar to Arrow’s. I prove that this is so, and end by discussing the plausibility of the axioms required for the theorem.

The best arguments for possible worlds as states of affairs furnish us with equally good arguments for impossible worlds of the same sort. I argue for a theory of impossible worlds on which the impossible worlds correspond to maximal inconsistent classes of propositions. Three objections are rejected. In the final part of the paper, I present a menu of impossible worlds and explore some of their interesting formal properties.

At first glance, impossible world semantics appear to be useful adaptations of normal modal logic. Proponents of impossible worlds argue, e.g., that in the context of metaphysical disagreement, impossible worlds would provide a key to modelling the respective dispute situation. The same philosophers also argue that we need impossible worlds to model what they consider to be the conceivability of logical impossibilities. With the help of Wittgenstein’s early philosophy, or, better said, with what I believe to be a visualisation of (...) his ideas on nesting models for possibility, I develop some thoughts on the likely shared weaknesses of such arguments for nonnormal world approaches. Said goes hand in hand with the supplementary proposal of rethinking our conventional nesting models for possibility. (shrink)

Review of Chris Mortensen, The Impossible Arises: Oscar Reutersvärd and his Contemporaries, Bloomington: Indiana University Press, 2022, pp. vii + 152, $50.00 (hardback).

Among the most telling atheistic arguments are those to the effect that the existence of any being that meets standard divine specifications is impossible – that there not only is not but could not be any such being.

According to a theorem recently proved in the theory of logical aggregation, any nonconstant social judgment function that satisfies independence of irrelevant alternatives (IIA) is dictatorial. We show that the strong and not very plausible IIA condition can be replaced with a minimal independence assumption plus a Pareto-like condition. This new version of the impossibility theorem likens it to Arrow’s and arguably enhances its paradoxical value.

A standing challenge in the theory of counterfactuals is to solve the “deviation problem”. Consider ordinary counterfactuals involving an antecedent concerning a difference from the actual course of events at a particular time, and a consequent concerning, at least in part, what happens at a later time. In the possible worlds framework, the problem is often put in terms of which are the relevant antecedent worlds. Desiderata for the solution include that the relevant antecedent worlds be governed by the actual (...) laws of nature with no miracles; that the past in those worlds before the antecedent time matches the actual past; that the account is compatible with determinism, and that many of our ordinary counterfactual judgments are correct, and would be correct even given determinism. Many theorists have compromised on one or more of these desiderata, but this paper presents an account employing impossible worlds that satisfies them all. (shrink)

This paper argues for a view of free will that I will call the conceptual impossibility of the truth of free will error theory - the conceptual impossibility thesis. I will argue that given the concept of free will we in fact deploy, it is impossible for our free will judgements - judgements regarding whether some action is free or not - to be systematically false. Since we do judge many of our actions to be free, it follows (...) from the conceptual impossibility thesis that many of our actions are in fact free. Hence it follows that free will error theory - the view that no judgement of the form ‘action A was performed freely’ - is false. I will show taking seriously the conceptual impossibility thesis helps makes good sense of some seemingly inconsistent results in recent experimental philosophy work on determinism and our concept of free will. Further, I will present some reasons why we should expect to find similar results for every other factor we might have thought was important for free will. (shrink)

Modal phenomena in general, and modal claims in particular, present a problem for contemporary philosophers. The truth conditions of modal claims differ from those of nonemodal claims. I discuss a widely accepted strategy that posits possible and impossible worlds in order to analyze modal claims and thus systematize our intuitions about modal reality.