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)

The traditional possible-worlds model of belief describes agents as ‘logically omniscient’ in the sense that they believe all logical consequences of what they believe, including all logical truths. This is widely considered a problem if we want to reason about the epistemic lives of non-ideal agents who—much like ordinary human beings—are logically competent, but not logically omniscient. A popular strategy for avoiding logical omniscience centers around the use of impossible worlds: worlds that, in one way or another, violate the (...) laws of logic. In this paper, we argue that existing impossible-worlds models of belief fail to describe agents who are both logically non-omniscient and logically competent. To model such agents, we argue, we need to ‘dynamize’ the impossible-worlds framework in a way that allows us to capture not only what agents believe, but also what they are able to infer from what they believe. In light of this diagnosis, we go on to develop the formal details of a dynamic impossible-worlds framework, and show that it successfully models agents who are both logically non-omniscient and logically competent. (shrink)

Some philosophers advance the claim that the phenomena of logical omniscience and of the indiscernibility of metaphysical statements, which arise in (certain) interpretations of normal modal logic, provide strong reasons in favour of impossible world approaches. These two specific lines of argument will be presented and discussed in this paper. Contrary to the recent much-held view that the characteristics of these two phenomena provide us with strong reasons to adopt impossible world approaches, the view defended here is that no (...) such ‘knock-down arguments’ do emanate on those grounds. This is not to rule out that there cannot be any other good reasons for assuming impossible world semantics. However, the discussion of a further argument for impossible worlds will suggest that different attempts to argue for them likely present intertwined problems. (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)

A survey of logical problems for the concept of omniscience.

A simple argument against Lewisian modal realism as portrayed in On the Plurality of World arises from its treatment of doxastic modalities. It is easily shown that if it is true, it is impossible to doubt the theory on ontological grounds, or, that, if it is possible to maintain doubt about modal realism’s existential postulate, it has to be false. The argument hinges on the fact that modal realism’s main ontological hypothesis, if true, is necessarily true.

The article analyzes and criticizes the assumptions of Peter Van Inwagen’s argument for the alleged contradiction of the foreknowledge of God and human freedom. The argument is based on the sine qua non condition of human freedom defined as access to possible worlds containing such a continuation of the present in which the agent implements a different action than will be realized de facto in the future. The condition also contains that in every possible continuation of the present state of (...) affairs, the same propositions about the ‘present past’ (the past before the present moment) are true as are true in the present state of affairs. The paper argues that Van Inwagen’s reasoning is inconclusive, it contains the type of mistake of confusing conditional impossibility with unconditional and presents a methodologically wrong method of solving a philosophical problem. It is because in the very construction of the problem determining the available solution. The article points to the possibility that the human freedom of some action is not excluded by the fact that specific past facts logically entail that this event will occur. (shrink)

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.

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 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)

Typical puzzles for de se attitudes by Perry and Lewis are laid out and contrasted with the original version of Jackson's Knowledge Argument. It is argued, from an epistemic perspective, that de se attitudes can be explained by looking at the way internal/introspective knowledge is formed without resorting to acquaintance or making assumptions about the Mind/Body problem.

A probability aggregation rule assigns to each profile of probability functions across a group of individuals (representing their individual probability assignments to some propositions) a collective probability function (representing the group's probability assignment). The rule is “non-manipulable” if no group member can manipulate the collective probability for any proposition in the direction of his or her own probability by misrepresenting his or her probability function (“strategic voting”). We show that, except in trivial cases, no probability aggregation rule satisfying two mild (...) conditions (non-dictatorship and consensus preservation) is non-manipulable. (shrink)

We present a framework for epistemic logic, modeling the logical aspects of System 1 and System 2 cognitive processes, as per dual process theories of reasoning. The framework combines non-normal worlds semantics with the techniques of Dynamic Epistemic Logic. It models non-logically-omniscient, but moderately rational agents: their System 1 makes fast sense of incoming information by integrating it on the basis of their background knowledge and beliefs. Their System 2 allows them to slowly, step-wise unpack some of the logical consequences (...) of such knowledge and beliefs, by paying a cognitive cost. The framework is applied to three instances of limited rationality, widely discussed in cognitive psychology: Stereotypical Thinking, the Framing Effect, and the Anchoring Effect. (shrink)

A Cantorian argument that there is no set of all truths. There is, for the same reason, no possible world as a maximal set of propositions. And omniscience is logically impossible.

The subject of this article is Modal-Epistemic Arithmetic (MEA), a theory introduced by Horsten to interpret Epistemic Arithmetic (EA), which in turn was introduced by Shapiro to interpret Heyting Arithmetic. I will show how to interpret MEA in EA such that one can prove that the interpretation of EA is MEA is faithful. Moreover, I will show that one can get rid of a particular Platonist assumption. Then I will discuss models for MEA in light of the problems of logical (...) omniscience and logical competence. Awareness models, impossible worlds models and syntactical models have been introduced to deal with the first problem. Certain conditions on the accessibility relations are needed to deal with the second problem. I go on to argue that those models are subject to the problem of quantifying in, for which I will provide a solution. (shrink)

It is sometimes argued that autonomous decision-making requires that the decision-maker’s desires are authentic, i.e., “genuine,” “truly her own,” “not out of character,” or similar. In this article, it is argued that a method to reliably determine the authenticity (or inauthenticity) of a desire cannot be developed. A taxonomy of characteristics displayed by different theories of authenticity is introduced and applied to evaluate such theories categorically, in contrast to the prior approach of treating them individually. The conclusion is drawn that, (...) in practice, the authenticity of desires cannot be reliably determined. It is suggested that authenticity should therefore not be employed in informed consent practices in healthcare. (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)

One set of neglected problems consists of paradoxes of omniscience clearly recognizable as forms of the Liar, and these I have never seen raised at all. Other neglected problems are difficulties for omniscience posed by recent work on belief de se and essential indexicals. These have not yet been given the attention they deserve.

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)

According to Jago (2014a), logical omniscience is really part of a deeper paradox. Jago develops an epistemic logic with principles of indeterminate closure to solve this paradox, but his official semantics is difficult to navigate, it is motivated in part by substantive metaphysics, and the logic is not axiomatized. In this paper, I simplify this epistemic logic by adapting the hyperintensional semantic framework of Sedlár (2021). My first goal is metaphysical neutrality. The solution to the epistemic paradox should not (...) require appeal to a metaphysics of truth-makers, situations, or impossible worlds, by contrast with Jago’s official semantics. My second goal is to elaborate on the proof theory. I show how to axiomatize a family of logics with principles of indeterminate epistemic closure. (shrink)

According to global skepticism, we know nothing. According to local skepticism, we know nothing in some particular area or domain of discourse. Unlike their global counterparts, local skeptics think they can contain our invincible ignorance within limited bounds. I argue that they are mistaken. Local skepticism, particularly the kinds that most often get defended, cannot stay local: if there are domains whose truths we cannot know, then there must be claims outside those domains that we cannot know even if they (...) are true. My argument focuses on one popular form of local skepticism, ethical skepticism, but I believe that the argument generalizes to cover other forms as well. (shrink)

Charging others with hypocrisy often acts as a way of rejecting the practical reasons they attempt to give (Herstein, 2017). There are some merits to a practice of rejecting reasons. To accept others’ provided reasons as valid is to affirm their authority in the relevant normative domain (Isserow and Klein, 2017). Conversely, to reject these reasons as invalid is to undermine the reason-givers’ authority in the domain. However, this practice can be rife with abuse—if we allow charges of ‘Hypocrite!’ to (...) take hold too broadly, we risk compromising the entire enterprise of reason-giving. I propose that one form of such abuse has already entered into our normative vocabulary with the concept of ‘hypocritical advice.’ At best, this term plays a superfluous role in our normative vocabulary; at worst, its vagueness perpetuates a vicious practice of reason-rejecting. Regardless of the severity of its impact on normative discourse, I will argue herein that we should do away with talk of ‘hypocritical advice.’ -/- I begin by echoing a standard distinction between second- and third-personal reasons and the corresponding types of authority that ground agents’ abilities to give reasons of each kind (sec. 2). After briefly discussing the connection between authority and hypocrisy (sec. 3), I argue that most purported cases of hypocritical advice-giving rest on a confusion between an utterance as communicating second- or third-personal reasons (sec. 4). Against recent suggestions that reasons given unambiguously as advice can be hypocritical, I demonstrate that the basis for rejecting third-personal reasons given in hypocritical advice is an interestingly different one than for rejecting second-personal reasons given through blame (sec. 5). I close with some final considerations against keeping ‘hypocritical advice’ in our normative vocabulary. (shrink)

For some contemporary liberal philosophers, a huge concern is liberal neutrality, which is the idea that the state should be neutral among competing conceptions of the moral good pursued by the people. In The Morality of Freedom, Joseph Raz argues that we can neither achieve nor even approximate such neutrality. He shows that neutrality and fairness are different ideas. His notion of neutrality is stricter than John Rawls's and Ronald Dworkin's. Raz shows that both helping and not helping can be (...) neutral or non-neutral, thus neutrality is chimerical. Wojciech Sadurski's appeal to rational expectations does not necessarily tell us which action is neutral. Distinguishing between comprehensive and narrow neutrality, Raz also claims that only the former is a proper response to conflicts. Sadurski criticizes it, claiming that conflicts are comprehensive in a sense which does not deny the adequacy of the narrow neutrality. In reality, however, it is almost impossible to achieve even the narrow neutrality. A theory is presented to explain why political neutrality is almost impossible to achieve. Philosophically, there is no neutral ground for neutral politics. (shrink)

In the debate about Christian attitudes to other religions, a threefold typology has emerged depicting differing Christian responses: pluralism, inclusivism and exclusivism. (This typology is not restricted to the Christian debate alone.) Traditionally, pluralism is opposed to exclusivism, the former claiming that it is arrogant and untenable to make exclusive truth claims, and that all religions are potentially equal paths to salvation and truth. In contrast, I argue that pluralism must always logically be a form of exclusivism and that nothing (...) called pluralism really exists. The main purpose of my paper is to show that there is no high-ground in the pluralist position, for in principle its logic is no different from the exclusivist position. If this is established, then the debate can proceed with more substantial issues regarding the justification and clarification of truth claims. (shrink)

The paper that follows continues a discussion with Tomis Kapitan in the pages of this journal over the compatibility of divine agency with divine foreknowledge. I had earlier argued against two premises in Kapitan's case for omniscient impotence: (i) that intentionally A-ing presupposes prior acquisition of the intention to A, and (ii) that acquiring the intention to A presupposes prior ignorance whether one will A. In response to my criticisms, Kapitan has recently offered new defences for these two premises. I (...) show in reply why neither defence succeeds in rehabilitating the case against omniscient agency. (Note that the very first sentence of the published version has a misprint: instead of "To claim that divine foreknowledge is inconsistent with divine agency has been pressed with increasing frequency of late . . .", it should read, "_The_ claim . . ."!). (shrink)

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.

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)

I argue that relations between non-collocated spatial entities, between non-identical topological spaces, and between non-identical basic building blocks of space, do not exist. If any spatially located entities are not at the same spatial location, or if any topological spaces or basic building blocks of space are non-identical, I will argue that there are no relations between or among them. The arguments I present are arguments that I have not seen in the literature.

The historical sensibility of Western modernity is best captured by the phrase “acting upon a story that we can believe.” Whereas the most famous stories of historians facilitated nation-building processes, philosophers of history told the largest possible story to act upon: history itself. When the rise of an overwhelming postwar skepticism about the modern idea of history discredited the entire enterprise, the historical sensibility of “acting upon a story that we can believe” fell apart to its constituents: action, story form, (...) and belief in a feasible future outcome. Its constituent parts are nevertheless still hold, either separately or in paired arrangements. First, believable stories are still told, but without an equally believable future outcome to facilitate. Second, in the shape of what I call the prospect of unprecedented change, there still is a feasible vision of a future (in prospects of technology and the Anthropocene), but it defies story form. And third, it is even possible to upon that feasible future, but such action aims at avoiding worst case scenarios instead of facilitating best outcomes. These are, I believe, features of an emerging postwar historical sensibility that the theory and philosophy of history is yet to understand. (shrink)

Reconciling the existence of a perfectly good God with the reality of evil in the world seems to be an impossible - or rather an unimaginable endeavour for some scholars. J. L. Mackie, for instance, maintains a logical incompatibility thesis, stating that three of the essential attributes of God, namely: omnipotence, omniscience and omnibenevolence can not be consistently upheld like the theists maintain, in the face of the reality of evil and human suffering in the world. Scholars like William (...) Rowe, David Hume and J. S. Mill also contend that every instance or trace of evil and suffering in the actual human world makes the existence of the creator of the world who is also perfectly good at best, probable. However, some scholars have attempted to explain the compatibility of the existence of a perfectly good God with the reality of evil in the world. This very endeavour is known in philosophy of religion and theology as theodicy. There are four traditional types of theodicy: The Augustinian tradition, the Irananaean tradition, the Hickian Soul making tradition and process theodicy. Using the methods of analysis and critical argumentation, we attempt a critical re-evaluation of these theodicies in this paper. Our critical investigation reveals that these theodicies inhere some weaknesses which render them insufficient in the rationalisation of the compatibility of the existence of a perfectly good God with the reality of evil in the world. The problems with each of the theodicies are meticulously explained in the paper. (shrink)

This note briefly discusses the observation of elapsed time in a flat universe while exploring the argument of past-eternal time versus emergent time in cosmology. A flat universe with an incomplete past forever has a finite age. Despite an infinite number of Planck time coordinates independent of phenomena and endless expansion, a flat universe never develops an age with an infinite number of Planck times. This observation indicates the impossibility of infinitely elapsed time in the future or past, which (...) limits acceptable scientific models of cosmology. (shrink)

John Abbruzzese has recently attempted a defense of omniscience against a series of my attacks. This affords me a welcome occasion to clarify some of the arguments, to pursue some neglected subtleties, and to re-think some important complications. In the end, however, I must insist that at least three of four crucial arguments really do show an omniscient being to be impossible. Abbruzzese sometimes misunderstands the forms of the argument themselves, and quite generally misunderstands their force.

The coherence of independent reports provides a strong reason to believe that the reports are true. This plausible claim has come under attack from recent work in Bayesian epistemology. This work shows that, under certain probabilistic conditions, coherence cannot increase the probability of the target claim. These theorems are taken to demonstrate that epistemic coherentism is untenable. To date no one has investigated how these results bear on different conceptions of coherence. I investigate this situation using Thagard’s ECHO model of (...) explanatory coherence. Thagard’s ECHO model provides a natural representation of the evidential significance of multiple independent reports. (shrink)

A number of examples have been given of physical systems (both classical and quantum mechanical) which when provided with a (continuously variable) computable input will give a non-computable output. It has been suggested that these systems might allow one to design analogue machines which would calculate the values of some number-theoretic non-computable function. Analysis of the examples show that the suggestion is wrong. In Section 4 I claim that given a reasonable definition of analogue machine it will always be wrong. (...) The claim is to be read not so much as a dogmatic assertion, but rather as a challenge. -/- In Sections 1 and 2 I discuss analogue machines, and lay down some conditions which I believe they must satisfy. In Section I discuss the particular forms which a paradigm undecidable problem (or non-computable function) may take. In Sections 5 and 6 I justify any claim for two particular examples lying within the range of classical physics, and in Section 7 I justify it for two (closely connected) examples from quantum mechanics, and discuss, very briefly, other possible quantum mechanical situations. Section 8 contains various remarks and comments. In Section 9 I consider the suggestion made by Penrose that a (future) theory of quantum gravity may predict non-locally-determined, and perhaps non-computable patterns of growth for microsopic structures. My conclusion is that such a theory will have to have non-computability built into it. (shrink)

Aumann’s theorem states that no individual should agree to disagree under a range of assumptions. Political liberalism appears to presuppose these assumptions with the idealized conditions of public reason. We argue Aumann’s theorem demonstrates they nevertheless cannot be simultaneously held with what is arguably political liberalism’s most central tenet. That is, the tenet of reasonable pluralism, which implies we can rationally agree to disagree over conceptions of the good. We finish by elaborating a way of relaxing one of the theorem’s (...) axioms that arguably lends itself to a coherent account of political liberalism, namely the condition of indexical independence. (shrink)

A key premise of the kalam cosmological argument is that the universe began to exist. However, while a number of philosophers have offered powerful criticisms of William Lane Craig’s defense of the premise, J.P. Moreland has also offered a number of unique arguments in support of it, and to date, little attention has been paid to these in the literature. In this paper, I attempt to go some way toward redressing this matter. In particular, I shall argue that Moreland’s philosophical (...) arguments against the possibility of traversing a beginningless past are unsuccessful. (shrink)

Since the noun phrase `artificial intelligence' (AI) was coined, it has been debated whether humans are able to create intelligence using technology. We shed new light on this question from the point of view of themodynamics and mathematics. First, we define what it is to be an agent (device) that could be the bearer of AI. Then we show that the mainstream definitions of `intelligence' proposed by Hutter and others and still accepted by the AI community are too weak even (...) to capture what is involved when we ascribe intelligence to an insect. We then summarise the highly useful definition of basic (arthropod) intelligence proposed by Rodney Brooks, and we identify the properties that an AI agent would need to possess in order to be the bearer of intelligence by this definition. Finally, we show that, from the perspective of the disciplines needed to create such an agent, namely mathematics and physics, these properties are realisable by neither implicit nor explicit mathematical design nor by setting up an environment in which an AI could evolve spontaneously. (shrink)

One of the central strengths of Salem's analysis of Nasserism is that she recognizes both its world-historical significance as a progressive nationalist movement, and its severe limitations. In the first section of this paper, I discuss Salem's notion of the "afterlives" of the Nasserist project by drawing attention to one of the most debilitating legacies of that project, namely the transformation of Egyptian politics into petty bourgeois politics. In the second section, I argue that while Salem does not explicitly draw (...) on Hegel's understanding of tragedy in her account of Nasserism, her analysis of Nasserism essentially amounts to depicting it as a Hegelian tragedy. By placing Salem's book in conversation with Hegel (and his philosophy of action), we can make explicit what I take to be one of the central claims made by Salem, namely that when passing judgment on past and present national liberation movements we should remember that innocence is "only non-action, like the mere being of a stone" [nur das Nichttun wie das Sein eines Steines] (Hegel 1986, 346). In the third section of this paper, I raise some critical points about Salem's characterization of the nationalism that was associated with the Nasserist project, as well as about the deployment of the concept of modernity in her analysis. I argue that her account of modernity in the book does not distinguish between the concept of modernity as it refers to a certain kind of normative philosophical discourse, and modernization theory qua theory of development. Finally, I draw on Salem's use of the concept of hegemony in order to pose a question regarding the political significance of the contemporary cultural hegemony of Islamist movements in Egypt. (shrink)

Diana Pérez (2005) criticizes Davidson’s argument for the thesis that there is no thought without language, and offers an alternative defense of that thesis on the basis of empirical studies on developmental psychology. In this comment I argue that more recent studies do not seem to affect Davidson’s argument in the way Pérez suggests, and that her alternative defense of the thesis that there is no thought without language is insufficient. At the end, I offer a sketch of how a (...) weaker and more tenable version of the argument could be articulated. (shrink)

In this article, I argue that it is impossible to complete infinitely many tasks in a finite time. A key premise in my argument is that the only way to get to 0 tasks remaining is from 1 task remaining, when tasks are done 1-by-1. I suggest that the only way to deny this premise is by begging the question, that is, by assuming that supertasks are possible. I go on to present one reason why this conclusion (that supertasks are (...) impossible) is important, namely that it implies a new verdict on a decision puzzle propounded by Jeffrey Barrett and Frank Arntzenius. (shrink)

Agents know some but not all logical consequences of what they know. Agents seem to be neither logically omniscient nor logically incompetent. Yet finding an intermediate standard of minimal rationality has proven difficult. In this paper, I take suggestions found in the literature (Lewis, 1988; Hawke, Özgün and Berto, 2020; Plebani and Spolaore, 2021) and join the forces of subject matter and impossible worlds approaches to devise a new solution to this quandary. I do so by combining a space of (...) FDE worlds (Berto and Jago, 2019) with a Lewisian (1988) understanding of subject matters as partitions. By doing so, I show how subject matters impose some order in the anarchic space of FDE worlds, while the worlds allow for distinctions between contents which would not otherwise be available. Combining the two approaches, then, brings us closer to the desired closure principles for knowledge of minimally rational agents. (shrink)

Adam Smith argued that the ideal moral judge is both well-informed and impartial. As non-ideal moral agents, we tend only to be truly well-informed about those with whom we frequently interact. These are also those with whom we tend to have the closest affective bonds. Hence, those who are well-informed, like our friends, tend to make for partial judges, while those who are impartial, like strangers, tend to make for ill-informed ones. Combining these two traits in one person seems far (...) from straightforward. Still, if becoming well-informed is, as Smith also claims, a matter of imaginative perspective-taking with the “person principally concerned”, it might be possible to become well-informed without the emotional entanglement that comes from any actual proximity to those we judge. Against this intuition, I use Construal Level Theory to show that the tension between being well-informed and impartial is likely to persist even if we take any actual proximity out of the equation. I end by discussing some implications of this, and suggest that we should consider revising the ideal to accommodate them. (shrink)

In this essay, my goal is, first, to describe the most important contemporary philosophical approaches to the nature of time, and then, secondly, to discuss the ways in which those different accounts bear upon the question of the possibility of divine foreknowledge. I shall argue that different accounts of the nature of time give rise to different objections to the idea of divine foreknowledge, but that, in addition, there is a general argument for the impossibility of divine foreknowledge that (...) is independent of one’s account of the nature of time. (shrink)

In the philosophy of artificial intelligence (AI) we are often warned of machines built with the best possible intentions, killing everyone on the planet and in some cases, everything in our light cone. At the same time, however, we are also told of the utopian worlds that could be created with just a single superintelligent mind. If we’re ever to live in that utopia (or just avoid dystopia) it’s necessary we solve the control problem. The control problem asks how humans (...) would be able to control an AI arbitrarily. Nick Bostrom and other AI researchers have proposed different theoretical solutions to the control problem. In this paper, I will not look at the empirical question of how to solve the control problem. Instead, I will ask if we can solve it at all, a critical assumption most AI researchers have made is that we can. I propose, in fact, that we have a priori grounds for believing it is logically impossible to solve the control problem, since all superintelligent minds are, by definition, uncontrollable. (shrink)

Agents know some but not all logical consequences of what they know. Agents seem to be neither logically omniscient nor logically incompetent. Yet finding an intermediate standard of minimal rationality has proven difficult. In this paper, I take suggestions found in the literature (Lewis, 1988; Hawke, Özgün and Berto, 2020; Plebani and Spolaore, 2021) and join the forces of subject matter and impossible worlds approaches to devise a new solution to this quandary. I do so by combining a space of (...) FDE worlds (Berto and Jago, 2019) with a Lewisian (1988) understanding of subject matters as partitions. By doing so, I show how subject matters impose some order in the anarchic space of FDE worlds, while the worlds allow for distinctions between contents which would not otherwise be available. Combining the two approaches, then, brings us closer to the desired closure principles for knowledge of minimally rational agents. (shrink)

Galen Strawson’s Basic Argument is that because self-creation is required to be truly morally responsible and self-creation is impossible, it is impossible to be truly morally responsible for anything. I contend that the Basic Argument is unpersuasive and unsound. First, I argue that the moral luck debate shows that the self-creation requirement appears to be contradicted and supported by various parts of our commonsense ideas about moral responsibility, and that this ambivalence undermines the only reason that Strawson gives for the (...) self-creation requirement. Second, I argue that the self-creation requirement is so demanding that either it is an implausible requirement for a species of true moral responsibility that we take ourselves to have or it is a plausible requirement of a species of true moral responsibility that we have never taken ourselves to have. Third, I explain that Strawson overgeneralizes from instances of constitutive luck that obviously undermine moral responsibility to all kinds of constitutive luck. (shrink)

Evidentialism is the thesis, roughly, that one’s beliefs should fit one’s evidence. The enkratic principle is the thesis, roughly, that one’s beliefs should "line up" with one’s beliefs about which beliefs one ought to have. While both theses have seemed attractive to many, they jointly entail the controversial thesis that self-misleading evidence is impossible. That is to say, if evidentialism and the enkratic principle are both true, one’s evidence cannot support certain false beliefs about which beliefs one’s evidence supports. Recently, (...) a number of epistemologists have challenged the thesis that self-misleading evidence is impossible on the grounds that misleading higher-order evidence does not have the kind of strong and systematic defeating force that would be needed to rule out the possibility of such self-misleading evidence. Here I respond to this challenge by proposing an account of higher-order defeat that does, indeed, render self-misleading evidence impossible. Central to the proposal is the idea that higher-order evidence acquires its normative force by influencing which conditional beliefs it is rational to have. What emerges, I argue, is an independently plausible view of higher-order evidence, which has the additional benefit of allowing us to reconcile evidentialism with the enkratic principle. (shrink)

We propose a solution to the problem of logical omniscience in what we take to be its fundamental version: as concerning arbitrary agents and the knowledge attitude per se. Our logic of knowledge is a spin-off from a general theory of thick content, whereby the content of a sentence has two components: an intension, taking care of truth conditions; and a topic, taking care of subject matter. We present a list of plausible logical validities and invalidities for the logic (...) of knowledge per se for arbitrary agents, and isolate three explanatory factors for them: the topic-sensitivity of content; the fragmentation of knowledge states; the defeasibility of knowledge acquisition. We then present a novel dynamic epistemic logic that yields precisely the desired validities and invalidities, for which we provide expressivity and completeness results. We contrast this with related systems and address possible objections. (shrink)