We present a formal semantics for epistemic logic, capturing the notion of knowability relative to information (KRI). Like Dretske, we move from the platitude that what an agent can know depends on her (empirical) information. We treat operators of the form K_AB (‘B is knowable on the basis of information A’) as variably strict quantifiers over worlds with a topic- or aboutness- preservation constraint. Variable strictness models the non-monotonicity of knowledge acquisition while allowing knowledge to be intrinsically stable. Aboutness-preservation (...) models the topic-sensitivity of information, allowing us to invalidate controversial forms of epistemic closure while validating less controversial ones. Thus, unlike the standard modal framework for epistemic logic, KRI accommodates plausible approaches to the Kripke-Harman dogmatism paradox, which bear on non-monotonicity, or on topic-sensitivity. KRI also strikes a better balance between agent idealization and a non-trivial logic of knowledge ascriptions. (shrink)

This paper draws out and connects two neglected issues in Kant’s conception of a priori knowledge. Both concern topics that have been important to contemporary epistemology and to formal epistemology in particular: knowability and luminosity. Does Kant commit to some form of knowability principle according to which certain necessary truths are in principle knowable to beings like us? Does Kant commit to some form of luminosity principle according to which, if a subject knows a priori, then they can (...) know that they know a priori? I defend affirmative answers to both of these questions, and by considering the special kind of modality involved in Kant’s conceptions of possible experience and the essential completability of metaphysics, I argue that his combination of knowability and luminosity principles leads Kant into difficulty. (shrink)

Famously, the Church–Fitch paradox of knowability is a deductive argument from the thesis that all truths are knowable to the conclusion that all truths are known. In this argument, knowability is analyzed in terms of having the possibility to know. Several philosophers have objected to this analysis, because it turns knowability into a nonfactive notion. In addition, they claim that, if the knowability thesis is reformulated with the help of factive concepts of knowability, then omniscience (...) can be avoided. In this article we will look closer at two proposals along these lines :557–568, 1985; Fuhrmann in Synthese 191:1627–1648, 2014a), because there are formal models available for each. It will be argued that, even though the problem of omniscience can be averted, the problem of possible or potential omniscience cannot: there is an accessible state at which all truths are known. Furthermore, it will be argued that possible or potential omniscience is a price that is too high to pay. Others who have proposed to solve the paradox with the help of a factive concept of knowability should take note :53–73, 2010; Spencer in Mind 126:466–497, 2017). (shrink)

Fitch's knowability paradox shows that for each unknown truth there is also an unknowable truth, a result which has been thought both odd in itself and at odds with views which impose epistemic constraints on truth and/or meaningfulness. Here a solution is considered which has received little attention in the debate but which carries prima facie plausibility. The decidability solution is to accept that Fitch sentences are unknowably true but deny the significance of this on the grounds that Fitch (...) sentences are nevertheless decidable. The decidability solution is particularly attractive for those whose primary concern is an epistemic constraint on meaningfulness (‘verificationists’). For those whose main concern is truth (‘anti-realists’), the situation is more complex: Melia takes the solution to exonerate anti-realism completely; Williamson sees it as completely irrelevant. The truth lies between these two extremes: there is one broad anti-realist commitment to which the solution does not apply, but there is also one, the “fundamental tenet” of anti-realism according to Dummett, to which it does. (shrink)

Anti-realism is plagued by Fitch’s paradox: the remarkable result that if one accepts that all truths are knowable, minimal assumptions about the nature of knowledge entail that every truth is known. Dorothy Edgington suggests to address this problem by understanding p is knowable to be a counterfactual claim, but her proposal must contend with a forceful objection by Timothy Williamson. I revisit Edgington’s basic idea and find that Williamson’s objection is obviated by a refined understanding of counterfactual knowability that (...) is grounded in possible courses of inquiry. I arrive at a precise definition of knowability that is not just a technical avoidance of paradox, but is metaphysically sound and does justice to the anti-realist idea. (shrink)

kk states that knowing entails knowing that one knows, and K¬K states that not knowing entails knowing that one does not know. In light of the arguments against kk and K¬K⁠, one might consider modally qualified variants of those principles. According to weak kk, knowing entails the possibility of knowing that one knows. And according to weakK¬K⁠, not knowing entails the possibility of knowing that one does not know. This paper shows that weak kk and weakK¬K are much stronger than (...) they initially appear. Jointly, they entail kk and K¬K⁠. And they are susceptible to variants of the standard arguments against kk and K¬K⁠. This has interesting implications for the debate on positive introspection and for deeper issues concerning the structure and limits of knowability. (shrink)

A novel solution to the knowability paradox is proposed based on Kant’s transcendental epistemology. The ‘paradox’ refers to a simple argument from the moderate claim that all truths are knowable to the extreme claim that all truths are known. It is significant because anti-realists have wanted to maintain knowability but reject omniscience. The core of the proposed solution is to concede realism about epistemic statements while maintaining anti-realism about non-epistemic statements. Transcendental epistemology supports such a view by providing (...) for a sharp distinction between how we come to understand and apply epistemic versus non-epistemic concepts, the former through our capacity for a special kind of reflective self-knowledge Kant calls ‘transcendental apperception’. The proposal is a version of restriction strategy: it solves the paradox by restricting the anti-realist’s knowability principle. Restriction strategies have been a common response to the paradox but previous versions face serious difficulties: either they result in a knowability principle too weak to do the work anti-realists want it to, or they succumb to modified forms of the paradox, or they are ad hoc. It is argued that restricting knowability to non-epistemic statements by conceding realism about epistemic statements avoids all versions of the paradox, leaves enough for the anti-realist attack on classical logic, and, with the help of transcendental epistemology, is principled in a way that remains compatible with a thoroughly anti-realist outlook. (shrink)

It is often claimed that anti-realism is a form of transcendental idealism or that Kant is an anti-realist. It is also often claimed that anti-realists are committed to some form of knowability principle and that such principles have problematic consequences. It is therefore natural to ask whether Kant is so committed, and if he is, whether this leads him into difficulties. I argue that a standard reading of Kant does indeed have him committed to the claim that all empirical (...) truths are knowable and that this claim entails that there is no empirical truth that is never known. I extend the result to a priori truths and draw some general philosophical lessons from this extension. However, I then propose a re-examination of Kant’s notion of experience according to which he carefully eschews any commitment to empirical knowability. Finally I respond to a remaining problem that stems from a weaker, justified believability principle. (shrink)

Why should we avoid incoherence? An influential view tells us that incoherent combinations of attitudes are such that it is impossible for all of those attitudes to be simultaneously vindicated by the evidence. But it is not clear whether this view successfully explains what is wrong with certain akratic doxastic states. In this paper I flesh out an alternative response to that question, one according to which the problem with incoherent combinations of attitudes is that it is impossible for all (...) of those attitudes to be simultaneously knowledgeable. This alternative response explains what is wrong with akratic combinations of attitudes using commonly accepted epistemological theses. The paper still shows how this proposal is able to explain the badness of incoherent combinations involving the absence of attitudes, suspended judgment and credence. These explanations deploy the notions of knowledge and being in a position to know, instead of the notion of responding properly to the evidence. Finally, I suggest that this picture can be generalized to the realm of practical rationality as well. (shrink)

This paper shows that the knowability paradox isn’t a paradox because the derivation of the paradox is faulty. This is explained by showing that the K operator employed in generating the paradox is used equivocally and when the equivocation is eliminated the derivation fails.

This article focuses on the epistemological challenges of comprehending organic life. It explores the cognitive and experiential basis of the perspective that organisms are autonomous agents of their own teleological organization and development. According to Immanuel Kant and Hans Jonas, the conditions of the knowability of organic life lie within our mental faculties and inner experiences. This statement is often interpreted to mean that we cannot attain ontological knowledge about the life of an organism. Alternatively, attempts are made to (...) “naturalize” life, i.e. to explain the self-generating capacity of an organism from the interaction of its material components. In contrast, I posit that through the active mental representation of biological processes, such as the development of a plant, we can gain first-person insight into the life forces at play, suggesting a profound connection between our cognitive processes and the dynamic and teleological nature of life. Specifically, the parallels between life and our mental capacities lie in a blend of sensory perception, imaginative activity, conceptual thought, and the agential self, mirroring the physical structure and the autopoietic, teleological and agential organization of a living organism. It is shown that these parallels comprise four types of subject-object relationships. I propose and discuss that this correlation is not merely an analogy but reflects a deep ontological correspondence between life and mind and that this correspondence can provide empirical access to the study of life through first-person experience. I advocate for a re-evaluation of the materialistic view of nature to include qualities and experiences of life and mind, proposing that life’s properties can be “naturalized” by recognizing them as qualities we experience mentally. Overall, I call for a broader approach to understanding life that incorporates both empirical evidence and phenomenological, first-person experiences. (shrink)

The topic of this article is the closure of a priori knowability under a priori knowable material implication: if a material conditional is a priori knowable and if the antecedent is a priori knowable, then the consequent is a priori knowable as well. This principle is arguably correct under certain conditions, but there is at least one counterexample when completely unrestricted. To deal with this, Anderson proposes to restrict the closure principle to necessary truths and Horsten suggests to restrict (...) it to formulas that belong to less expressive languages. In this article it is argued that Horsten’s restriction strategy fails, because one can deduce that knowable ignorance entails necessary ignorance from the closure principle and some modest background assumptions, even if the expressive resources do not go beyond those needed to formulate the closure principle itself. It is also argued that it is hard to find a justification for Anderson’s restricted closure principle, because one cannot deduce it even if one assumes very strong modal and epistemic background principles. In addition, there is an independently plausible alternative closure principle that avoids all the problems without the need for restriction. (shrink)

A dynamic epistemic logic is presented in which the single agent can reason about his knowledge stages before and after announcements. The logic is generated by reinterpreting multi agent private announcements in a single agent environment. It is shown that a knowability principle is valid for such logic: any initially true ϕ can be known after a certain number of announcements.

History and Philosophy of Logic, Volume 33, Issue 1, Page 101-104, February 2012.

Widespread amongst scholars is the legend according to which Locke shows a strong aversion to abstract ideas, similar to that of Berkley in the Treatise. This legend is endorsed by influential commentators on Locke. He does not even propose the reduction of ideas to mental pictures (a reduction which in Berkeley and Hume will form the base of the negation of the existence of abstract ideas in the mind). Locke is not in the least afraid of abstract ideas; his constant (...) concern, which is evident in his treatment of the complex question of the relation between real and nominal essence, is to refute the position of the Scholastics, according to which a universal concept in the mind (post rem) reflects the universal present in all things as substantial form (the universal in re), without assuming positions which are purely conventionalist and nominalist with regard to knowledge, such as those of Mersenne, Gassendi, Hobbes and sceptical and anti-Cartesian free-thinkers. To show this, I offer an analysis of the relation Locke makes between real and nominal essence, with regard to the relations which link term to idea and idea to things. The nature of the relation between signifier and signified is variable, though, in the relation between ideas and things with respect to the various kinds of complex ideas which the human mind may frame. The greatest difference is to be found between complex ideas of mixed mode and complex ideas of substance. (shrink)

Even though evidence underdetermines theory, often in science one theory only is regarded as acceptable in the light of the evidence. This suggests there are additional unacknowledged assumptions which constrain what theories are to be accepted. In the case of physics, these additional assumptions are metaphysical theses concerning the comprehensibility and knowability of the universe. Rigour demands that these implicit assumptions be made explicit within science, so that they can be critically assessed and, we may hope improved. This leads (...) to a new conception of science, one which we need to adopt in order to solve the problem of induction. (shrink)

Both Wilfrid Sellars and John McDowell reject Kant’s conclusion that the world is fundamentally unknowable, and on similar grounds: each invokes conceptual change, what I call the diachronic instability of a conceptual scheme. The similarities end there, though. It is important to Sellars that the world is only knowable at “the end of inquiry” – he rejects a commonsense realism like McDowell’s for its inability to fully appreciate diachronic instability. To evaluate this disagreement, I consider Timothy Williamson’s argument that the (...) knowability thesis, as it rules out “elusive objects”, is problematically idealistic. I argue that McDowell’s insistence on diachronic instability suffices to address Williamson’s worry, and as such that his reply ought to be available to Sellars too. That Sellars would instead invoke the end of inquiry suggests it is he who underestimates the ineliminability of conceptual change. (shrink)

If language is to serve the basic purpose of communicating our attitudes, we must be constructed so as to form beliefs in those propositions that we truthfully assert on the basis of careful assent. Thus, other things being equal, I can rely on believing those things to which I give my careful assent. And so my ability to assent or dissent amounts to an ability to make up my mind about what I believe. This capacity, in tandem with a similar (...) capacity in respect of other attitudes, supports three important lessons. It means that I can know what I believe by seeing what commands my assent, that I can put aside the possibility of error in committing myself to holding such a belief, and that I can therefore perform as a person: I can organize my mind around commitments to which others are invited to hold me. (shrink)

If we want to say that all truths are knowable Fitch’s Paradox leads us to conclude that all truths are known. Is it a real philosophical problem or a mere modeling problem? Is it possible to express the idea of knowability using modal logic? The Knowability Principle is expressed by the formula: if Phi is true then it is possible to know that Phi. But what is the meaning of possibility in this context? Using standard modal operators under (...) what condition can we express the idea of knowability? We will in particular examine the subjacent relations of the modal operators in a Kripke Model. We will define the possibility as the possibility of learning opposed to an unclear possibility. Then we will show that Fitch’s Paradox becomes clearer and we will examine how the Knowability Principle could be expressed in such frame. (shrink)

Antirealists who hold the knowability thesis, namely that all truths are knowable, have been put on the defensive by the Church-Fitch paradox of knowability. Rejecting the non-factivity of the concept of knowability used in that paradox, Edgington has adopted a factive notion of knowability, according to which only actual truths are knowable. She has used this new notion to reformulate the knowability thesis. The result has been argued to be immune against the Church-Fitch paradox, but (...) it has encountered several other triviality objections. Schlöder in a forthcoming paper defends the general approach taken by Edgington, but amends it to save it in turn from the triviality objections. In this paper I will argue, first, that Schlöder's justification for the factivity of his version of the concept of knowability is vulnerable to criticism, but I will also offer an improved justification that is in the same spirit as his. To the extent that some philosophers are right about our intuitive concept of knowability being a factive one, it is important to explore factive concepts of knowability that are made formally precise. I will subsequently argue that Schlöder's version of the knowability thesis overgenerates knowledge or, in other words, it leads to attributions of knowledge where there is ignorance. This fits a general pattern for the research programme initiated by Edgington. This paper also contains preliminary investigations into the internal and logical structure of lines of inquiries, which raise interesting research questions. (shrink)

Fitch’s Paradox shows that if every truth is knowable, then every truth is known. Standard diagnoses identify the factivity/negative infallibility of the knowledge operator and Moorean contradictions as the root source of the result. This paper generalises Fitch’s result to show that such diagnoses are mistaken. In place of factivity/negative infallibility, the weaker assumption of any ‘level-bridging principle’ suffices. A consequence is that the result holds for some logics in which the “Moorean contradiction” commonly thought to underlie the result is (...) in fact consistent. This generalised result improves on the current understanding of Fitch’s result and widens the range of modalities of philosophical interest to which the result might be fruitfully applied. Along the way, we also consider a semantic explanation for Fitch’s result which answers a challenge raised by Kvanvig. (shrink)

In a recent paper Horsten embarked on a journey along the limits of the domain of the unknowable. Rather than knowability simpliciter, he considered a priori knowability, and by the latter he meant absolute provability, i.e. provability that is not relativized to a formal system. He presented an argument for the conclusion that it is not absolutely provable that there is a natural number of which it is true but absolutely unprovable that it has a certain property. The (...) argument depends on a description principle. I will argue that the latter principle implies the knowability of all arithmetical truths. Therefore, Horsten's argument is either sound but its conclusion is trivial, or his argument is unsound. (shrink)

According to the “paradox of knowability”, the moderate thesis that all truths are knowable – ... – implies the seemingly preposterous claim that all truths are actually known – ... –, i.e. that we are omniscient. If Fitch’s argument were successful, it would amount to a knockdown rebuttal of anti-realism by reductio. In the paper I defend the nowadays rather neglected strategy of intuitionistic revisionism. Employing only intuitionistically acceptable rules of inference, the conclusion of the argument is, firstly, not (...) ..., but .... Secondly, even if there were an intuitionistically acceptable proof of ..., i.e. an argument based on a different set of premises, the conclusion would have to be interpreted in accordance with Heyting semantics, and read in this way, the apparently preposterous conclusion would be true on conceptual grounds and acceptable even from a realist point of view. Fitch’s argument, understood as an immanent critique of verificationism, fails because in a debate dealing with the justification of deduction there can be no interpreted formal language on which realists and anti-realists could agree. Thus, the underlying problem is that a satisfactory solution to the “problem of shared content” is not available. I conclude with some remarks on the proposals by J. Salerno and N. Tennant to reconstruct certain arguments in the debate on anti-realism by establishing aporias. (shrink)

Many philosophical discussions hinge on the concept of knowability. For example, there is a blooming literature on the so-called paradox of knowability. How to understand this notion, however? In this paper, we examine several approaches to the notion: the naive approach to take knowability as the possibility to know, the counterfactual approach endorsed by Edgington (1985) and Schlöder (2019) , approaches based on the notion of a capacity or ability to know (Fara 2010, Humphreys 2011), and finally, (...) approaches that make use of the resources of dynamic epistemic logic (van Benthem 2004, Holliday 2017). (shrink)

1) We will begin by offering a short introduction to Epistemic Logic and presenting Fitch’s paradox in an epistemic‑modal logic. (2) Then, we will proceed to presenting three Epistemic Temporal logical frameworks creat‑ ed by Hoshi (2009) : TPAL (Temporal Public Announcement Logic), TAPAL (Temporal Arbitrary Public Announcement Logic) and TPAL+P ! (Temporal Public Announcement Logic with Labeled Past Operators). We will show how Hoshi stated the Verificationist Thesis in the language of TAPAL and analyze his argument on why this (...) version of it is immune from paradox. (3) Edgington (1985) offered an interpretation of the Verificationist Thesis that blocks Fitch’s paradox and we will propose a way to formulate it in a TAPAL‑based lan‑ guage. The language we will use is a combination of TAPAL and TPAL+P ! with an Indefinite (Unlabeled) Past Operator (TAPAL+P !+P). Using indexed satisfi‑ ability relations (as introduced in (Wang 2010 ; 2011)) we will offer a prospec ‑ tive semantics for this language. We will investigate whether the tentative re‑ formulation of Edgington’s Verificationist Thesis in TAPAL+P !+P is free from paradox and adequate to Edgington’s ideas on how „all truths are knowable“ should be interpreted. (shrink)

In a recent paper, Alexander argues that relaxing the requirement that sound knowers know their own soundness might provide a solution to Fitch’s paradox and introduces a suitable axiomatic system where the paradox is avoided. In this paper an analysis of this solution is proposed according to which the effective move for solving the paradox depends on the axiomatic treatment of the ontic modality rather than the limitations imposed on the epistemic one. It is then shown that, once the ontic (...) modality is standardly introduced, the paradox still follows and, in addition, some puzzling consequences arise. (shrink)

This paper is about two topics: metaepistemological absolutism and the epistemic principles governing perceptual warrant. Our aim is to highlight—by taking the debate between dogmatists and conservativists about perceptual warrant as a case study—a surprising and hitherto unnoticed problem with metaepistemological absolutism, at least as it has been influentially defended by Paul Boghossian as the principal metaepistemological contrast point to relativism. What we find is that the metaepistemological commitments at play on both sides of this dogmatism/conservativism debate do not line (...) up with epistemic relativism nor do they line up with absolutism, at least as Boghossian articulates this position. What this case study reveals is the need in metaepistemological option space for the recognition of a weaker and less tendentious form of absolutism, what we call “environment relativism”. On this view, epistemic principles are knowable, objective, and they can serve as the basis of particular epistemic evaluations, but their validity is relative to the wider global environment in which they are applied. (shrink)

KK is the thesis that if you can know p, you can know that you can know p. Though it’s unpopular, a flurry of considerations has recently emerged in its favour. Here we add fuel to the fire: standard resources allow us to show that any failure of KK will lead to the knowability and assertability of abominable indicative conditionals of the form ‘If I don’t know it, p’. Such conditionals are manifestly not assertable—a fact that KK defenders can (...) easily explain. I survey a variety of KK-denying responses and find them wanting. Those who object to the knowability of such conditionals must either deny the possibility of harmony between knowledge and belief, or deny well-supported connections between conditional and unconditional attitudes. Meanwhile, those who grant knowability owe us an explanation of such conditionals’ unassertability—yet no successful explanations are on offer. Upshot: we have new evidence for KK. (shrink)

Skeptical theism (ST) may undercut the key inference in the evidential argument from evil, but it does so at a cost. If ST is true, then we lose our ability to assess the all things considered (ATC) value of natural events and states of affairs. And if we lose that ability, a whole slew of undesirable consequences follow. So goes a common consequential critique of ST. In a recent article, Anderson has argued that this consequential critique is flawed. Anderson claims (...) that ST only has the consequence that we lack epistemic access to potentially God-justifying reasons for permitting a prima facie “bad” (or “evil”) event. But this is very different from lacking epistemic access to the ATC value of such events. God could have an (unknowable) reason for not intervening to prevent E and yet E could still be (knowably) ATC-bad. Ingenious though it is, this article argues that Anderson’s attempted defence of ST is flawed. This is for two reasons. First, and most importantly, the consequential critique does not rely on the questionable assumption he identifies. Indeed, the argument can be made quite easily by relying purely on Anderson’s distinction between God-justifying reasons for permitting E and the ATC value of E. And second, Anderson’s defence of his position, if correct, would serve to undermine the foundations of ST. (shrink)

Though there are many challenges to Ekman’s thesis that there are basic emotions with universal corresponding facial expressions, our main criticism revolves around the extent to which grounding situations alter how people read faces. To that end, we recruit testifying experimental studies that show identical faces expressing varying emotions when contextualized differently. Rather than dismissing these as illusions, we start with the position—generally favored by embodied thinkers—that situations are primary: they are where specifiable and hence knowable properties first show up. (...) We further argue that situationally inflected emotional expressions are informationally meaningful. We reject the idea that reading expressions is primarily about ascertaining internal mental states, arguing instead that people are registering overall situations when looking at faces. However, if mind is understood as a situated phenomenon that extends into active ecological frames, then one can still argue that mindreading is going on. Although we do not claim isolated things like cliffs or cars have agency, we speculate networked systems with cliffs, people, cars, bears, etc., collectively function with intentionality, more so if advancing a robust situated mind thesis, contra figures like Dennett who argue that people over-impute mind to things. Our position has practical implications insofar as it casts doubts on recent attempts to develop AI systems that extract emotional intent out of facial expressions since many of these systems are grounded on Ekman’s basic view. (shrink)

This paper defends a new norm of assertion: Assert that p only if you are in a position to know that p. We test the norm by judging its performance in explaining three phenomena that appear jointly inexplicable at first: Moorean paradoxes, lottery propositions, and selfless assertions. The norm succeeds by tethering unassertability to unknowability while untethering belief from assertion. The PtK‐norm foregrounds the public nature of assertion as a practice that can be other‐regarding, allowing asserters to act in the (...) best interests of their audience when psychological pressures would otherwise prevent them from communicating the knowable truth. (shrink)

Both realist and anti-realist accounts of natural kinds possess prima facie virtues: realists can straightforwardly make sense of the apparent objectivity of the natural kinds, and anti-realists, their knowability. This paper formulates a properly anti-realist account designed to capture both merits. In particular, it recommends understanding natural kinds as ‘categorical bottlenecks,’ those categories that not only best serve us, with our idiosyncratic aims and cognitive capacities, but also those of a wide range of alternative agents. By endorsing an ultimately (...) subjective categorical principle, this view sidesteps epistemological difficulties facing realist views. Yet, it nevertheless identifies natural kinds that are fairly, though not completely, stance-independent or objective. (shrink)

I argue that the Hume of the Treatise maintains an account of knowledge according to which (i) every instance of knowledge must be an immediately present perception (i.e., an impression or an idea); (ii) an object of this perception must be a token of a knowable relation; (iii) this token knowable relation must have parts of the instance of knowledge as relata (i.e., the same perception that has it as an object); and any perception that satisfies (i)-(iii) is an instance (...) of knowledge. I then apply this account to the case of sense perception. I argue that Hume holds that relations of impressions can be intuited, are knowable, and are necessary. For Hume, these relations constitute sensory knowledge. While Hume is rightly labeled an empiricist for many reasons, a close inspection of his account of knowledge reveals yet another way in which he deserves the label. (shrink)

The identity theory’s rise to prominence in analytic philosophy of mind during the late 1950s and early 1960s is widely seen as a watershed in the development of physicalism, in the sense that whereas logical behaviourism proposed analytic and a priori ascertainable identities between the meanings of mental and physical-behavioural concepts, the identity theory proposed synthetic and a posteriori knowable identities between mental and physical properties. While this watershed does exist, the standard account of it is misleading, as it is (...) founded in erroneous intensional misreadings of the logical positivists’—especially Carnap’s—extensional notions of translation and meaning, as well as misinterpretations of the positivists’ shift from the strong thesis of translation-physicalism to the weaker and more liberal notion of reduction-physicalism that occurred in the Unity of Science programme. After setting the historical record straight, the essay traces the first truly modern identity theory to Schlick’s pre-positivist views circa 1920 and goes on to explore its further development in Feigl, arguing that the fundamental difference between the Schlick-Feigl identity theory and the more familiar and influential Place-Smart-Armstrong identity theory has resurfaced in the deep and seemingly unbridgeable gulf in contemporary philosophy of consciousness between inflationary mentalism and deflationary physicalism. (shrink)

This paper argues for and explores the implications of the following epistemological principle for knowability a priori (with 'Ka' abbreviating 'it is knowable a priori that'). -/- (AK) For all ϕ, ψ such that ϕ semantically presupposes ψ: if Ka(ϕ), Ka(ψ). -/- Well-known arguments for the contingent a priori and a priori knowledge of logical truth founder when the semantic presuppositions of the putative items of knowledge are made explicit. Likewise, certain kinds of analytic truth turn out to carry (...) semantic presuppositions that make them ineligible as items of a priori knowledge. -/- On a happier note, I argue that (AK) offers an appealing, theory-neutral explanation of the a posteriori character of certain necessary identities, as well as an interesting rationalization for a commonplace linguistic maneuver in philosophical work on the a priori. (shrink)

This paper addresses the question whether future contingents are knowable, that is, whether one can know that things will go a certain way even though it is possible that things will not go that way. First I will consider a long-established view that implies a negative answer, and draw attention to some endemic problems that affect its credibility. Then I will sketch an alternative line of thought that prompts a positive answer: future contingents are knowable, although our epistemic access of (...) them is limited in some important respects. (shrink)

We consider a natural-language sentence that cannot be formally represented in a first-order language for epistemic two-dimensional semantics. We also prove this claim in the “Appendix” section. It turns out, however, that the most natural ways to repair the expressive inadequacy of the first-order language render moot the original philosophical motivation of formalizing a priori knowability as necessity along the diagonal.

In a recent paper, Melchior pursues a novel argumentative strategy against the sensitivity condition. His claim is that sensitivity suffers from a ‘heterogeneity problem:’ although some higher-order beliefs are knowable, other, very similar, higher-order beliefs are insensitive and so not knowable. Similarly, the conclusions of some bootstrapping arguments are insensitive, but others are not. In reply, I show that sensitivity does not treat different higher-order beliefs differently in the way that Melchior states and that while genuine bootstrapping arguments have insensitive (...) conclusions, the cases that Melchior describes as sensitive ‘bootstrapping’ arguments don’t deserve the name, since they are a perfectly good way of getting to know their conclusions. In sum, sensitivity doesn’t have a heterogeneity problem. (shrink)

There is a need to bring about a revolution in the philosophy of science, interpreted to be both the academic discipline, and the official view of the aims and methods of science upheld by the scientific community. At present both are dominated by the view that in science theories are chosen on the basis of empirical considerations alone, nothing being permanently accepted as a part of scientific knowledge independently of evidence. Biasing choice of theory in the direction of simplicity, unity (...) or explanatory power does not permanently commit science to the thesis that nature is simple or unified. This current ‘paradigm’ is, I argue, untenable. We need a new paradigm, which acknowledges that science makes a hierarchy of metaphysical assumptions concerning the comprehensibility and knowability of the universe, theories being chosen partly on the basis of compatibility with these assumptions. Eleven arguments are given for favouring this new ‘paradigm’ over the current one. (shrink)

At the heart of the Stoic theory of modality is a strict commitment to bivalence, even for future contingents. A commitment to both future truth and contingency has often been thought paradoxical. This paper argues that the Stoic retreat from necessity is successful. it maintains that the Stoics recognized three distinct senses of necessity and possibility: logical, metaphysical and providential. Logical necessity consists of truths that are knowable a priori. Metaphysical necessity consists of truths that are knowable a posteriori, a (...) world order according to certain metaphysical principles and natures that god crafts within the constraints of matter. Finally, what is providentially necessary is what occurs according to the chain of fate, but only once it is in process or past. -/- The method of the paper is a close reading of Diogenes Laertius 7.75, adducing broad textual evidence along the way, to show that the Stoic theory of modality embraces Philonian possibility, both that which is capable of being true as a matter of logical consistency, and that which is possible according to the bare fitness of the entity. What differentiates the Stoics from Philo is their additional commitment to possibility as opportunity, resisting the collapse of determinism into necessity. (shrink)

The timeless solution to the problem of divine foreknowledge and human freedom has many advantages. Still, the relationship between a timeless God and temporal beings is problematic in a number of ways. In this paper, we focus on the specific problems the timeless view has to deal with when certain assumptions on the metaphysics of time are taken on board. It is shown that on static conception of time God’s omniscience is easily accounted for, but human freedom is threatened, while (...) a dynamic conception has no problems with human freedom, but, on this view, some truths seem not to be knowable by a timeless God. We propose Fragmentalism as a metaphysics of time in which the divine timeless knowledge of temporal events and human freedom can be reconciled. -/- . (shrink)

The Comprehensibility of the Universe puts forward a radically new conception of science. According to the orthodox conception, scientific theories are accepted and rejected impartially with respect to evidence, no permanent assumption being made about the world independently of the evidence. Nicholas Maxwell argues that this orthodox view is untenable. He urges that in its place a new orthodoxy is needed, which sees science as making a hierarchy of metaphysical assumptions about the comprehensibility and knowability of the universe, these (...) assumptions asserting less and less as one ascends the hierarchy. This view has significant implications: that it is part of scientific knowledge that the universe is physically comprehensible; that metaphysics and philosophy are central to scientific knowledge; that science possesses a rational, if fallible, method of discovery; that a new understanding of scientific method and rationality is required. Maxwell argues that this new conception makes possible a natural resolution of long-standing philosophical problems about science, regarding simplicity, induction, and progress. His goal is the reform not just of the philosophy of science but of science itself, and the healing of the rift between the two. (shrink)

This essay reassesses the relation between Kant and Kripke on the relation between necessity and the a priori. Kripke famously argues against what he takes to be the traditional view that a statement is necessary only if it is a priori, where, very roughly, what it means for a statement to be necessary is that it is true and could not have been false and what it means for a statement to be a priori is that it is knowable independently (...) of experience. Call such a view the Entailment Thesis. Along with many Kant scholars, Kripke thinks that Kant endorses the Entailment Thesis. Thus Kripke and many others take his arguments against the Entailment Thesis to tell against Kant and to mark an important point of disagreement with him. I will argue that this is a mistake. Kant does not endorse the Entailment Thesis that Kripke and many others attribute to him. He does endorse two quite different theses concerning the relation between necessity and the a priori, as he conceives them. One is a matter of definition and the other is a very substantial philosophical thesis indeed—to establish it is the aim of the entire Critique of Pure Reason. But Kripke’s arguments against the Entailment Thesis tell against neither of Kant’s theses, as they involve crucially different conceptions of necessity and the a priori. This superficial lack of disagreement masks deep disagreements, but these result from divergent views regarding matters such as realism, modal epistemology, and philosophical methodology; views which Kant does a lot, and Kripke very little, to argue for. (shrink)

Millians about proper names typically claim that it is knowable apriori that Hesperus is Phosphorus. We argue that they should claim instead that it is knowable only aposteriori that Hesperus is Hesperus, since the Kripke-Putnam epistemic arguments against descriptivism are special cases of Quinean arguments that nothing is knowable apriori, and Millians have no resources to resist the more general Quinean arguments.

The received view in the history of the philosophy of psychology is that the logical positivists—Carnap and Hempel in particular—endorsed the position commonly known as “logical” or “analytical” behaviourism, according to which the relations between psychological statements and the physical-behavioural statements intended to give their meaning are analytic and knowable a priori. This chapter argues that this is sheer legend: most, if not all, such relations were viewed by the logical positivists as synthetic and knowable only a posteriori. It then (...) traces the origins of the legend to the logical positivists’ idiosyncratic extensional or at best weakly intensional use of what are now considered crucially strongly intensional semantic notions, such as “translation,” “meaning” and their cognates, focussing on a particular instance of this latter phenomenon, arguing that a conflation of explicit definition and analyticity may be the chief source of the legend. (shrink)