This paper is inspired by and develops on E. J. Lowe’s work, who writes in his book The Possibility of Metaphysics that ‘metaphysical possibility is an inescapable determinant of actuality’ (1998: 9). Metaphysics deals with possibilities – metaphysical possibilities – but is not able to determine what is actual without the help of empirical research. Accordingly, a delimitation of the space of possibilities is required. The resulting – controversial – picture is that we generally need to know whether (...) something is possible before we can know whether it is actual. In order to appreciate this picture, we need to understand Lowe’s slogan: ‘essence precedes existence’ (Lowe 2008: 40). This slogan has both an ontological and an epistemic reading. The ontological reading is related to the now familiar idea that essence grounds modality, as popularised by Kit Fine. The epistemic reading suggests that we can know the essence of some entity before we know whether or not that entity exists. However, this idea is often met with puzzlement and Lowe himself sadly passed away before he had a chance to clarify this framework. I will present the framework as I understand it, develop it on my own terms, and put forward a qualified defence of it. I will also illustrate how the framework can be put to use with a case study concerning the discovery of transuranic elements. (shrink)

Biological modalities, i.e., biologically possible, impossible, or necessary states of affairs have not received much attention from philosophers. Yet, it is widely agreed that there are biological constraints on physically possible states of affairs, such that not everything that is physically possible is also biologically possible, even if everything that is biologically possible is also physically possible. Furthermore, biologists use concepts that appear to be modal in nature, such as the concept of evolvability in evolutionary developmental biology, or “evo-devo.” The (...) present chapter investigates what kind of modality underlies the concept of evolvability. This concept tries to capture the capacity of an organism or a lineage to sustain genetic changes that enable it to evolve or to evolve adaptively. The basic idea of the proposed approach is to construe evolvability as a kind of accessibility in a modal space. The difficult part is to specify this modal space and the relevant accessibility relation. While there may not be a general way of defining such a relation, there exist model systems for which it is possible, e.g., evolving small RNAs. The modal space in such cases turns out to be quite distinct from those constructed by philosophers, e.g., David Lewis’s similarity metric for possible worlds. Even though the biological case examined here is quite special, attending to the way in which biological possibilities are modeled in this case harbors some general lessons about biological modalities, in particular their dependence on the explanatory goals of the models modeling modality. (shrink)

This essay challenges the widely accepted principle that a person is morally responsible for what he has done only if he could have done otherwise. The author considers situations in which there are sufficient conditions for a certain choice or action to be performed by someone, So that it is impossible for the person to choose or to do otherwise, But in which these conditions do not in any way bring it about that the person chooses or acts as he (...) does. In such situations the person may well be morally responsible for what he chooses or does despite his inability to choose or to do otherwise. Finally the author considers certain suggestions for revising the principle he rejects or for replacing it with a principle of an altogether different kind. (shrink)

This paper was chosen by The Philosopher’s Annual as one of the ten best articles appearing in print in 2000. Reprinted in Volume XXIII of The Philosopher’s Annual. In his very influential book David Chalmers argues that if physicalism is true then every positive truth is a priori entailed by the full physical description – this is called “the a priori entailment thesis – but ascriptions of phenomenal consciousness are not so entailed and he concludes that Physicalism is false. As (...) he puts it, “zombies” are metaphysically possible. I attempt to show that this argument is refuted by considering an analogous argument in the mouth of a zombie. The conclusion of this argument is false so one of the premises is false. I argue at length that this shows that the original conceivability argument also has a false premise and so is invalid. (shrink)

“There are no gaps in logical space,” David Lewis writes, giving voice to sentiment shared by many philosophers. But different natural ways of trying to make this sentiment precise turn out to conflict with one another. One is a *pattern* idea: “Any pattern of instantiation is metaphysically possible.” Another is a *cut and paste* idea: “For any objects in any worlds, there exists a world that contains any number of duplicates of all of those objects.” We use resources from model (...) theory to show the inconsistency of certain packages of combinatorial principles and the consistency of others. (shrink)

David Lewis holds that a single possible world can provide more than one way things could be. But what are possible worlds good for if they come apart from ways things could be? We can make sense of this if we go in for a metaphysical understanding of what the world is. The world does not include everything that is the case—only the genuine facts. Understood this way, Lewis's “cheap haecceitism” amounts to a kind of metaphysical anti-haecceitism: it says there (...) aren't any genuine facts about individuals over and above their qualitative roles. (shrink)

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)

Many epistemologists call themselves ‘fallibilists’. But many philosophers of language hold that the meaning of epistemic usages of ‘possible’ ensures a close knowledge- possibility link : a subject’s utterance of ‘it’s possible that not-p’ is true only if the subject does not know that p. This seems to suggest that whatever the core insight behind fallibilism is, it can’t be that a subject could have knowledge which is, for them, possibly false. I argue that, on the contrary, subjects can (...) have such possibly false knowledge. My ultimate aim, then, is to vindicate a very robust form of fallibilism. Uniquely, however, the account I offer does this while also allowing that concessive knowledge attributions – sentences of the form “I know that p, but it’s possible that not-p” – are not only infelicitous but actually false whenever uttered. The account predicts this result without conceding KPL. I argue that my account has the resources to explain some related cases for which the KPL account yields the wrong predictions. Taken as a whole, the linguistic data not only do not support the proposal that subjects cannot have possibly false knowledge, but indeed positively favor the proposal that they can. (shrink)

We ordinarily think that we human beings have agency: we have control over our choices and make a difference to our environments. Yet it is not obvious how agency can fit into a physical world that is governed by exceptionless laws of nature. In particular, it is unclear how agency is possible if those laws are deterministic and the universe functions like a mechanical clockwork. In this short paper, I first explain the apparent conflict between agency and physical determinism (referring (...) to recent work by Helen Steward on "agency incompatibilism"), then review some salient responses one might give to this conflict, and finally sketch a response that rests on a distinction between “physical” and “agential possibilities.” Agency, I suggest, is a higher-level phenomenon, which comes with its own level-specific notion of possibility, and it cannot be adequately analyzed in physical terms alone or just through the lens of physical possibility. (The paper was written as an informal position paper for a symposium on "Possibilities".). (shrink)

In this chapter, I survey what I call Lewisian approaches to modality: approaches that analyze modality in terms of concrete possible worlds and their parts. I take the following four theses to be characteristic of Lewisian approaches to modality. (1) There is no primitive modality. (2) There exists a plurality of concrete possible worlds. (3) Actuality is an indexical concept. (4) Modality de re is to be analyzed in terms of counterparts, not transworld identity. After an introductory section in which (...) I motivate analyzing modality in terms of possible worlds, I devote one section to each of these four theses. For each thesis, I take Lewis’s interpretation and defense as my starting point. I then consider and endorse alternative ways of accepting the thesis, some of which disagree substantially with Lewis’s interpretation or defense. There is more than one way to be a Lewisian about modality. (shrink)

In the history of modern philosophy systematic connections were assumed to hold between the modal concepts of logical possibility and necessity and the concept of conceivability. However, in the eyes of many contemporary philosophers, insuperable objections face any attempt to analyze the modal concepts in terms of conceivability. It is important to keep in mind that a philosophical explanation of modality does not have to take the form of a reductive analysis. In this paper I attempt to provide a (...) response-dependent account of the modal concepts in terms of conceivability along the lines of a nonreductive model of explanation. (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.

Necessity, but not possibility, is typically thought to be rare and suspicion-worthy. This manifests in an asymmetry in the burden of proof incurred by modal claims. In general, claims to the effect that some proposition is impossible/necessary require significant argumentative support and, in general, claims to the effect that some proposition is possible/contingent are thought to be justified freely or by default. Call this the possibility bias. In this paper, I argue that the possibility bias is not (...) epistemically justified. We should regard possibility with at least as much suspicion, that is to say as incurring at least as much of an explanatory demand, as necessity. In fact, I suggest that we might even be justified in reversing the burden of proof asymmetry and adopting a necessity bias. This has quite radical implications for philosophical methodology and hence for many first-order philosophical concerns. (shrink)

We provide a new perspective on the relation between the space of description of an object and the appearance of novelties. One of the aims of this perspective is to facilitate the interaction between mathematics and historical sciences. The definition of novelties is paradoxical: if one can define in advance the possibles, then they are not genuinely new. By analyzing the situation in set theory, we show that defining generic (i.e., shared) and specific (i.e., individual) properties of elements of a (...) set are radically different notions. As a result, generic and specific definitions of possibilities cannot be conflated. We argue that genuinely stating possibilities requires that their meaning has to be made explicit. For example, in physics, properties playing theoretical roles are generic; then, generic reasoning is sufficient to define possibilities. By contrast, in music, we argue that specific properties matter, and generic definitions become insufficient. Then, the notion of new possibilities becomes relevant and irreducible. In biology, among other examples, the generic definition of the space of DNA sequences is insufficient to state phenotypic possibilities even if we assume complete genetic determinism. The generic properties of this space are relevant for sequencing or DNA duplication, but they are inadequate to understand phenotypes. We develop a strong concept of biological novelties which justifies the notion of new possibilities and is more robust than the notion of changing description spaces. These biological novelties are not generic outcomes from an initial situation. They are specific and this specificity is associated with biological functions, that is to say, with a specific causal structure. Thus, we think that in contrast with physics, the concept of new possibilities is necessary for biology. (shrink)

The new …eld of judgment aggregation aims to …nd collective judgments on logically interconnected propositions. Recent impossibility results establish limitations on the possibility to vote independently on the propositions. I show that, fortunately, the impossibility results do not apply to a wide class of realistic agendas once propositions like “if a then b” are adequately modelled, namely as subjunctive implications rather than material implications. For these agendas, consistent and complete collective judgments can be reached through appropriate quota rules (which (...) decide propositions using acceptance thresholds). I characterise the class of these quota rules. I also prove an abstract result that characterises consistent aggregation for arbitrary agendas in a general logic. (shrink)

This argument demonstrates that within an infinite framework of possibilities, the existence of God—a necessary, omnipotent, omniscient, and perfectly good being—is not only logically possible but metaphysically inevitable. By grounding its premises in logical coherence, probabilistic reasoning, and metaphysical necessity, the argument provides a profound exploration of existence, divinity, and humanity's role in infinite potential. It offers implications for ethical striving, collective responsibility, and the divine foundation of reality. -/- .

Among the most remarkable developments in metaphysics since the 1950’s is the explosion of philosophical interest in possible worlds. This paper proposes an explanation of what possible worlds are, and argues that this proposal, the interpreted models conception, should be attractive to anyone who thinks that modal facts are primitive, and so not to be explained in terms of some non-modal notion of “possible world.” I articulate three constraints on any acceptable primitivist explanation of the nature of possible worlds, and (...) show that the interpreted models conception meets the three constraints. (shrink)

A common view of how-possibly explanations in biology treats them as explanatorily incomplete. In addition to this interpretation of how-possibly explanation, I argue that there is another interpretation, one which features what I term “explanatory strategies.” This strategy-centered interpretation of how-possibly explanation centers on there being a different explanatory context within which how-possibly explanations are offered. I contend that, in conditions where this strategy context is recognized, how-possibly explanations can be understood as complete explanations. I defend this alternative interpretation by (...) analyzing the explanatory value of simple physical models the nineteenth century developmental biologist Wilhelm His constructed for animal development. (shrink)

This chapter provides an introduction to possible worlds semantics in both logic and the philosophy of language, including a discussion of some of the advantages and challenges for possible worlds semantics.

What makes democracy valuable? One traditional answer holds that participating in democratic self-government amounts to a kind of autonomy: it enables citizens to be the authors of their political affairs. Many contemporary philosophers, however, are skeptical. We are autonomous, they argue, when important features of our lives are up to us, but in a democracy we merely have a say in a process of collective choice. In this paper, we defend the possibility of democratic autonomy, by advancing a conception (...) of it which is impervious to this objection. At the core of our account is the idea of joint authorship. You are a joint author of something when that thing expresses your joint intentions. Democracy may not make any one of us sole author of our political affairs, but it can make us their joint authors. It is in such joint authorship, we claim, that the intrinsic value of democratic self-government consists. (shrink)

Typically, nudging is a technique for steering the choices of people without giving reasons or using enforcement. In benevolent cases, it is used when people are insufficiently responsive to reason. The nudger triggers automatic cognitive mechanisms – sometimes even biases – in smart ways in order to push irrational people in the right direction. Interestingly, this technique can also be applied to doxastic attitudes. Someone who is doxastically unresponsive to evidence can be nudged into forming true beliefs or doxastic attitudes (...) that are propositionally justified. When doxastic nudging uses non-rational mechanisms, the worry is that nudging cannot result in justified beliefs or knowledge, as the resulting doxastic attitudes lack the right kind of basis. In this paper, I will argue that given the right background views about knowledge, justified beliefs and the relevant processes, epistemic nudging is possible even in these cases. That is, all kinds of nudging can – in appropriate circumstances – produce justified beliefs or knowledge in the nudgee. (shrink)

The necessity of origin suggests that a person’s identity is determined by the particular pair of gametes from which the person originated. An implication is that speculative scenarios concerning how we might otherwise have been had our gametic origins been different are dismissed as being metaphysically impossible. Given, however, that many of these speculations are intelligible and commonplace in the discourses of competent speakers, it is overhasty to dismiss them as mistakes. This paper offers a way of understanding these speculations (...) that does not commit them to incoherence but aims to make the best sense of what they are expressing. Using the philosophical framework of two‐dimensional semantics, it proposes that the speculative scenarios are best analysed as epistemic possibilities, rather than as metaphysical possibilities. It then explores some implications of this analysis for the ethical challenges associated with the non‐identity problem. (shrink)

This article gives two arguments for believing that our society is unknowingly guilty of serious, large-scale wrongdoing. First is an inductive argument: most other societies, in history and in the world today, have been unknowingly guilty of serious wrongdoing, so ours probably is too. Second is a disjunctive argument: there are a large number of distinct ways in which our practices could turn out to be horribly wrong, so even if no particular hypothesized moral mistake strikes us as very likely, (...) the disjunction of all such mistakes should receive significant credence. The article then discusses what our society should do in light of the likelihood that we are doing something seriously wrong: we should regard intellectual progress, of the sort that will allow us to find and correct our moral mistakes as soon as possible, as an urgent moral priority rather than as a mere luxury; and we should also consider it important to save resources and cultivate flexibility, so that when the time comes to change our policies we will be able to do so quickly and smoothly. (shrink)

Realists about possible worlds typically identify possible worlds with abstract objects, such as propositions or properties. However, they face a significant objection due to Lewis (1986), to the effect that there is no way to explain how possible worlds-as-abstract objects represent possibilities. In this paper, I describe a response to this objection on behalf of realists. The response is to identify possible worlds with propositions, but to deny that propositions are abstract objects, or indeed objects at all. Instead, I argue (...) that realists should follow Prior (1971) and others in treating higher-order quantification (e.g. quantification into predicate or sentence position) as a genuine form of quantification in its own right, and so in particular, not to be analysed in terms of first-order quantification over abstract objects. I argue that from this ‘higher-orderist’ perspective, there is a relatively straightforward answer to the question of how possible worlds-as-propositions succeed in representing possibilities. (shrink)

Despite much discussion over the existence of moral facts, metaethicists have largely ignored the related question of their possibility. This paper addresses the issue from the moral error theorist’s perspective, and shows how the arguments that error theorists have produced against the existence of moral facts at this world, if sound, also show that moral facts are impossible, at least at worlds non-morally identical to our own and, on some versions of the error theory, at any world. So error (...) theorists’ arguments warrant a stronger conclusion than has previously been noticed. This may appear to make them vulnerable to counterarguments that take the possibility of moral facts as a premise. However, I show that any such arguments would be question-begging. (shrink)

In this paper, a novel experimental task is developed for testing the highly influential, but experimentally underexplored, possible worlds account of conditionals (Stalnaker, 1968; Lewis, 1973). In Experiment 1, this new task is used to test both indicative and subjunctive conditionals. For indicative conditionals, five competing truth tables are compared, including the previously untested, multi-dimensional possible worlds semantics of Bradley (2012). In Experiment 2, these results are replicated and it is shown that they cannot be accounted for by an alternative (...) hypothesis proposed by our reviewers. In Experiment 3, individual variation in truth assignments of indicative conditionals is investigated via Bayesian mixture models that classify participants as following one of several competing models. As a novelty of this study, it is found that a possible worlds semantics of Lewis and Stalnaker is capable of accounting for participants’ aggregate truth value assignments in this task. Applied to indicative conditionals, we show across three experiments, that the theory both captures participants’ truth values at the aggregate level (Experiments 1 and 2) and that it makes up the largest subgroup in the analysis of individual variation in our experimental paradigm (Experiment 3). (shrink)

The Humean view that conceivability entails possibility can be criticized via input from cognitive psychology. A mainstream view here has it that there are two candidate codings for mental representations (one of them being, according to some, reducible to the other): the linguistic and the pictorial, the difference between the two consisting in the degree of arbitrariness of the representation relation. If the conceivability of P at issue for Humeans involves the having of a linguistic mental representation, then it (...) is easy to show that we can conceive the impossible, for impossibilities can be represented by meaningful bits of language. If the conceivability of P amounts to the pictorial imaginability of a situation verifying P, then the question is whether the imagination at issue works purely qualitatively, that is, only by phenomenological resemblance with the imagined scenario. If so, the range of situations imaginable in this way is too limited to have a significant role in modal epistemology. If not, imagination will involve some arbitrary labeling component, which turns out to be sufficient for imagining the impossible. And if the relevant imagination is neither linguistic nor pictorial, Humeans will appear to resort to some representational magic, until they come up with a theory of a ‘third code’ for mental representations. (shrink)

A number of authors, including me, have argued that the output of our most complex climate models, that is, of global climate models and Earth system models, should be assessed possibilistically. Worries about the viability of doing so have also been expressed. I examine the assessment of the output of relatively simple climate models in the context of discovery and point out that this assessment is of epistemic possibilities. At the same time, I show that the concept of epistemic (...) class='Hi'>possibility used in the relevant studies does not fit available analyses of this concept. Moreover, I provide an alternative analysis that does fit the studies and broad climate modelling practices as well as meshes with my existing view that climate model assessment should typically be of real possibilities. On my analysis, to assert that a proposition is epistemically possible is to assert that it is not known to be false and is consistent with at least approximate knowledge of the basic way things are. I, finally, consider some of the implications of my discussion for available possibilistic views of climate model assessment and for worries about such views. I conclude that my view helps to address worries about such assessment and permits using the full range of climate models in it. (shrink)

Natural modalities are often analysed from an abstract point of view where they are associated with putative laws of nature. However, the way possibilities are represented in physics is more complex. Lagrangian mechanics, for instance, involves two different layers of modalities: kinematical and dynamical possibilities. This paper examines the status of these two layers, both in the classical and quantum case. The quantum case is particularly problematic: we identify four possible interpretive options. The upshot is that a close inspection of (...) the way possibilities are represented in physics could lead to new ways of thinking about natural modalities. (shrink)

Possible world semantics has been gradually fine-grained over the years. First, simple extensional semantics was fine-grained by relativizing it to worlds considered as counterfactual, thus generating standard possible-world semantics, which was later further fine-grained by relativizing it to worlds considered as actual, thus generating two-dimensional semantics. However, worlds considered as actual were only considered with respect to the empirical facts obtaining in such worlds. This paper shows that no less of an important role is played by another feature of actual (...) worlds, namely, the criteria of identity that obtain in such worlds. (shrink)

It is natural to assume that every value bearer must be good, bad, or neutral. This paper argues that this assumption is false if value incomparability is possible. More precisely, if value incommensurability is possible, then there is a fourth category of absolute value, in addition to the good, the bad, and the neutral.

The standard semantics for counterfactuals ensures that any counterfactual with a true antecedent and true consequent is itself true. There have been many recent attempts to amend the standard semantics to avoid this result. I show that these proposals invalidate a number of further principles of the standard logic of counterfactuals. The case against the automatic truth of counterfactuals with true components does not extend to these further principles, however, so it is not clear that rejecting the latter should be (...) a consequence of rejecting the former. Instead I consider how one might defuse putative counterexamples to the truth of true-true counterfactuals. (shrink)

Despite the notions of possible worlds and substances are very important subjects of contemporary metaphysics, there are relatively few attempts to combine these in a united framework. This paper considers the metaphysical model of the origins and the evolution of possible worlds that occurs from an interaction between substances. I involve Leibniz’s doctrine of the striving possibles that every possibility of substance has its own essence and tendency towards existence. It is supposed that the activities of substances are constantly (...) aimed at using this tendency in all possible ways. Only the consistent and stable interactions between the substances give birth to stable objects in one of many worlds. Thus activity of substances changes from the possible modality of being to the actual modality of being in form of existence of the worlds. I divide substance’s possibility into two aspects—dynamic (possible or virtual history) and static (possible or potential mutual state). Thanks to the summation of virtual histories, in the possible modality of being, the maximal number of virtual histories is combined into the actual history in the actual modality. (shrink)

The article investigates the sceptical challenge from an informationtheoretic perspective. Its main goal is to articulate and defend the view that either informational scepticism is radical, but then it is epistemologically innocuous because redundant; or it is moderate, but then epistemologically beneficial because useful. In order to pursue this cooptation strategy, the article is divided into seven sections. Section 1 sets up the problem. Section 2 introduces Borei numbers as a convenient way to refer uniformly to (the data that individuate) (...) different possible worlds. Section 3 adopts the Hamming distance between Borei numbers as a metric to calculate the distance between possible worlds. In Sects. 4 and 5, radical and moderate informational scepticism are analysed using Borei numbers and Hamming distances, and shown to be either harmless (extreme form) or actually fruitful (moderate form). Section 6 further clarifies the approach by replying to some potential objections. In the conclusion, the Peircean nature of the overall approach is briefly discussed. (shrink)

Traditionally, philosophy has been strictly a human domain, with wide applications in science and ethics. However, with the rapid advancement of natural language processing technologies like ChatGPT, the question of whether artificial intelligence can engage in philosophical thinking is becoming increasingly important. This work first clarifies the meaning of philosophy based on its historical background, then explores the possibility of AI engaging in philosophy. We conclude that AI has reached a stage where it can engage in philosophical inquiry. The (...) study also examines differences between AI and humans in terms of statistical processing, creativity, the frame problem, and intrinsic motivation, assessing whether AI can philosophize in a manner indistinguishable from humans. While AI can imitate many aspects of human philosophical inquiry, the lack of intrinsic motivation remains a significant limitation. Finally, the paper explores the potential for AI to offer unique philosophical insights through its diversity and limitless learning capacity, which could open new avenues for philosophical exploration far beyond conventional human perspectives. (shrink)

In this paper I explore the relationship between the idea of possible worlds and the notion of the beauty of God. I argue that there is a clear contradiction between the idea that God is utterly and completely beautiful on the one hand and the notion that He contains within himself all possible worlds on the other. Since some of the possible worlds residing in the mind of the deity are ugly, their presence seems to compromise God's complete and utter (...) beauty. (shrink)

Metaphysically possible worlds have many uses. Epistemically possible worlds promise to be similarly useful, especially in connection with propositions and propositional attitudes. However, I argue that there is a serious threat to the natural accounts of epistemically possible worlds, from a version of Russell’s paradox. I contrast this threat with David Kaplan’s problem for metaphysical possible world semantics: Kaplan’s problem can be straightforwardly rebutted, the problems I raise cannot. I argue that although there may be coherent accounts of epistemically possible (...) worlds with fruitful applications, any such an account must fundamentally compromise the basic idea behind epistemic possibility. (shrink)

I use modal logic and transfinite set-theory to define metaphysical foundations for a general theory of computation. A possible universe is a certain kind of situation; a situation is a set of facts. An algorithm is a certain kind of inductively defined property. A machine is a series of situations that instantiates an algorithm in a certain way. There are finite as well as transfinite algorithms and machines of any degree of complexity (e.g., Turing and super-Turing machines and more). There (...) are physically and metaphysically possible machines. There is an iterative hierarchy of logically possible machines in the iterative hierarchy of sets. Some algorithms are such that machines that instantiate them are minds. So there is an iterative hierarchy of finitely and transfinitely complex minds. (shrink)

In response to suspicions concerning the use of possible worlds in philosophy, this brief paper proposes an analysis of possibility that requires only a single world, using a combination of temporal logic and a potentiality operator.

In this paper I propose a formalization, using modal logic, of the notion of possibility that phoneticians use when they judge speech sounds to be possible or impossible. I argue that the most natural candidate for a modal logic of phonetic possibility is the modal system T.

We often ascribe possibility to the scenes that are displayed by mental or nonmental sensory images. The paper presents a novel argument for thinking that we are prima facie justified in ascribing metaphysical possibility to what is displayed by suitable visual images, and it argues that many of our imagery‐based ascriptions of metaphysical possibility are therefore prima facie justified. Some potential objections to the arguments are discussed, and some potential extensions of them, to cover nonvisual forms of (...) imagery and nonmetaphysical forms of possibility, are endorsed. (shrink)

The purpose of this paper is not to show that the answer to the question in the title is ‘no’, but to show that it is ‘probably not’, at least on one particular theory of memory. Assuming that an experience will only be an episodic memory if we are ‘disposed to take the relevant experience into account when judging about the past’ (Debus 2010, p. 25), there are many obstacles to answering the question in the affirmative. If one holds that (...) it is possible to have episodic memories during dreams, they will have to accept more implications than may be palatable. Specifically, they will have to believe, contra Sosa (2007), that we can actually make judgments during dreams and not just imagine doing so; that we retain a fairly high degree of rationality during dreams; and that there is a respectable sense in which we can refer to the past at all when we dream. (shrink)

Conventional wisdom suggests that the power to do otherwise is necessary for being morally responsible. While much of the literature on alternative possibilities has focused on Frankfurt’s argument against this claim, I instead focus on one of Dennett’s (1984) arguments against it. This argument appeals to cases of volitional necessity rather than cases featuring counterfactual interveners. van Inwagen (1989) and Kane (1996) appeal to the notion of ‘character setting’ to argue that these cases do not show that the power to (...) do otherwise is unnecessary for moral responsibility. In this paper, I argue that their character setting response is unsuccessful. (shrink)

I argue that if David Lewis’ modal realism is true, modal realists from different possible worlds can fall in love with each other. I offer a method for uniquely picking out possible people who are in love with us and not with our counterparts. Impossible lovers and trans-world love letters are considered. Anticipating objections, I argue that we can stand in the right kinds of relations to merely possible people to be in love with them and that ending a trans-world (...) relationship to start a relationship with an actual person isn't cruel to one's otherworldly lover. (shrink)

In this paper, I examine the case that has been made for origin essentialism and find it wanting. I focus on the arguments of Nathan Salmon and Graeme Forbes. Like most origin essentialists, Salmon and Forbes have been concerned to respect the intuition that slight variation in the origin of an artifact or organism is possible. But, I argue, both of their arguments fail to respect this intuition. Salmon's argument depends on a sufficiency principle for cross-world identity, which should be (...) rejected, if - as Salmon concedes - a given artifact might have been originally made from slightly different material. Similarly, Forbes's argument succeeds only if essentially the same argument can be used to establish a claim that - by his own admission - is too strong, namely that no variation, however slight, in an organism's origin is possible. (shrink)

A Benacerraf–Field challenge is an argument intended to show that common realist theories of a given domain are untenable: such theories make it impossible to explain how we’ve arrived at the truth in that domain, and insofar as a theory makes our reliability in a domain inexplicable, we must either reject that theory or give up the relevant beliefs. But there’s no consensus about what would count here as a satisfactory explanation of our reliability. It’s sometimes suggested that giving such (...) an explanation would involve showing that our beliefs meet some modal condition, but realists have claimed that this sort of modal interpretation of the challenge deprives it of any force: since the facts in question are metaphysically necessary and so obtain in all possible worlds, it’s trivially easy, even given realism, to show that our beliefs have the relevant modal features. Here I show that this claim is mistaken—what motivates a modal interpretation of the challenge in the first place also motivates an understanding of the relevant features in terms of epistemic possibilities rather than metaphysical possibilities, and there are indeed epistemically possible worlds where the facts in question don’t obtain. (shrink)

_ Source: _Volume 10, Issue 3, pp 441 - 456 Several kinds of historical alternatives are distinguished. Different kinds of historical alternatives are valuable to the practice of history for different reasons. Important uses for historical alternatives include representing different sides of historical disputes; distributing chances of different outcomes over alternatives; and offering explanations of why various alternatives did _not_ in fact happen. Consideration of counterfactuals about what would have happened had things been different in particular ways plays particularly useful (...) roles in reasoning about historical analogues of current conditions; reasoning about causal claims; and in evaluating historical explanations. When evaluating the role of alternative histories in historical thinking, we should keep in mind the uses of historical alternatives that go well beyond the long-term and specific scenarios that are the focus of so-called “counterfactual history”. (shrink)

The moral error theory, it seems, could be true. The mere possibility of its truth might also seem inconsequential. But it is not. For, I argue, there is a sense in which the moral error theory is possible that generates an argument against both non‐cognitivism and moral naturalism. I argue that it is an epistemic possibility that morality is subject to some form of wholesale error of the kind that would make the moral error theory true. Denying this (...) possibility has three unwelcome consequences such that allowing for and explaining it is an adequacy condition on meta‐ethical theories. Non‐cognitivism and moral naturalism, I argue, cannot capture the epistemic possibility of wholesale moral error and so are false. My argument additionally provides independent reason to accept Derek Parfit's claim that if moral non‐naturalism is false then nothing matters. I conclude that whether wholesale moral error is epistemically possible may be, in Richard Rorty's words, ‘one of those issues which puts everything up for grabs at once’ and that even if so, and even if non‐cognitivists and moral naturalists remain unmoved by an argument based upon it, this only helps to highlight the significance of my argument. (shrink)

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

Introduction: -/- Walking, illegally, down main Montreal thoroughfares with students in nightly demonstrations, with neighbors whom I barely knew before, banging pots and pans, and with tens, if not hundreds, of thousands of people on every 22nd of the month since March—this was unimaginable a year ago.1 Unimaginable that the collective and heterogeneous body, which is the “manif [demonstration]”, could feel so much like home, despite its internal differences. Unimaginable that this mutual dependence on one another could enable not only (...) collective protection from traffic and police but the affective strength and audacity to take back the street—a mutual dependence that includes the masked demonstrators ready to help when gassed by police. Unimaginable too that we would be breaking the law daily,2 that blocking traffic and seeing the city from the center of the street would become habit, and that as the “printemps érable” becomes summer, we would be investing our time in neighborhood assemblies, in weaving social bonds, and in sustaining and deepening the mobilization. -/- I say these actions were unimaginable not merely because the context that motivated the enlargement of the student movement into a popular struggle combines a number of unique features. Nor were they simply unimaginable because the Quebec I previously knew was marred by the Islamophobia and cultural racism made visible during the reasonable accommodation debates, a society whose mapping excluded me and for whose sake it would have been difficult to protest.3 Rather, I say these actions were unimaginable because the possibility of this popular and inclusive mobilization had not yet been created. It is this possibility that the Quebec student movement has created, I argue, not only in quantitative terms by engaging so many, but at the level of lived subjectivities and intercorporeal solidarity. The evolution of the movement should be understood, then, both as a swelling of its popular base and as an intensification and qualitative transformation of ways of life. (shrink)