Supervenience in metaethics is the notion that there can be no moral dif-ference between two acts, persons or events without some non-moral difference underlying it. If St. Francis is a good man, there could not be a man exactly like St. Francis in non-evaluative respects that is not good. The phenomenon was first systematically discussed by R. M. Hare (1952), who argued that realists about evaluative properties struggle to account for it. As is well established, Hare, and following him, Simon (...) Blackburn, mistakenly took the relevant phenomenon to be weak rather than strong supervenience, and the explanations they offered for it are accordingly outdated. In this paper, I present a non-factualist account of strong su-pervenience of the evaluative and argue that it fares better than compet-ing realist views in explaining the conceptual nature of the phenomenon, as well as in offering an account of the supervenience of the evaluative in general, rather than more narrowly the moral. While Hare and Blackburn were wrong about the specifics, they were right in that non-factualists can offer a plausible account of the supervenience of the evaluative, that in certain respects is superior to competing realist explanations. (shrink)

ABSTRACTEvaluative aesthetic discourse communicates that the speaker has had first-hand experience of what is talked about. If you call a book bewitching, it will be assumed that you have read the book. If you say that a building is beautiful, it will be assumed that you have had some visual experience with it. According to an influential view, this is because knowledge is a norm for assertion, and aesthetic knowledge requires first-hand experience. This paper criticizes this view and argues for (...) an alternative view, according to which aesthetic discourse expresses affective states of mind, analogously to how assertions express beliefs. It is because these affective states require first-hand experience that aesthetic discourse communicates that such acquaintance is at hand. The paper furthermore argues that the lack of an experience requirement for aesthetic belief ascriptions constitutes a problem for the kind of expressivist who claims that evaluative belief states are covert non-cognitive states. (shrink)

It is widely held within contemporary metaethics that there is a lack of linguistic support for evaluative expressivism. On the contrary, it seems that the predictions that expressivists make about evaluative discourse are not borne out. An instance of this is the so-called problem of missing Moorean infelicity. Expressivists maintain that evaluative statements express non-cognitive states of mind in a similar manner to how ordinary descriptive language expresses beliefs. Conjoining an ordinary assertion that p with the denial of being in (...) the corresponding belief state famously gives rise to Moorean infelicity:?? It’s raining but I don’t believe that it’s raining. If expressivists are right, then conjoining evaluative statements with the denial of being in the relevant non-cognitive state of mind should give rise to similar infelicity. However, as several theorists have pointed out, this does not seem to be the case. Statements like the following are not infelicitous: Murder is wrong but I don’t disapprove of it. In this paper, I argue that evaluative statements express the kind of states that are attributed by ‘find’-constructions in English and that these states are non-cognitive in nature. This addresses the problem of missing Moorean infelicity and, more generally, goes to show that there are linguistic facts which support expressivism about evaluative discourse. (shrink)

This brief note corrects an error in one of the reduction steps in my paper 'Normalisation for Bilateral Classical Logic with some Philosophical Remarks' published in the Journal of Applied Logics 8/2 (2021): 531-556.

This paper formulates a bilateral account of harmony that is an alternative to one proposed by Francez. It builds on an account of harmony for unilateral logic proposed by Kürbis and the observation that reading the rules for the connectives of bilateral logic bottom up gives the grounds and consequences of formulas with the opposite speech act. I formulate a process I call 'inversion' which allows the determination of assertive elimination rules from assertive introduction rules, and rejective elimination rules from (...) rejective introduction rules, and conversely. It corresponds to Francez's notion of vertical harmony. I also formulate a process I call 'conversion', which allows the determination of rejective introduction rules from assertive elimination rules and conversely, and the determination of assertive introduction rules from rejective elimination rules and conversely. It corresponds to Francez's notion of horizontal harmony. The account has a number of features that distinguish it from Francez's. (shrink)

This paper proves normalisation theorems for intuitionist and classical negative free logic, without and with the $\invertediota$ operator for definite descriptions. Rules specific to free logic give rise to new kinds of maximal formulas additional to those familiar from standard intuitionist and classical logic. When $\invertediota$ is added it must be ensured that reduction procedures involving replacements of parameters by terms do not introduce new maximal formulas of higher degree than the ones removed. The problem is solved by a rule (...) that permits restricting these terms in the rules for $\forall$, $\exists$ and $\invertediota$ to parameters or constants. A restricted subformula property for deductions in systems without $\invertediota$ is considered. It is improved upon by an alternative formalisation of free logic building on an idea of Ja\'skowski's. In the classical system the rules for $\invertediota$ require treatment known from normalisation for classical logic with $\lor$ or $\exists$. The philosophical significance of the results is also indicated. (shrink)

This paper discusses proof-theoretic semantics, the project of specifying the meanings of the logical constants in terms of rules of inference governing them. I concentrate on Michael Dummett’s and Dag Prawitz’ philosophical motivations and give precise characterisations of the crucial notions of harmony and stability, placed in the context of proving normalisation results in systems of natural deduction. I point out a problem for defining the meaning of negation in this framework and prospects for an account of the meanings of (...) modal operators in terms of rules of inference. (shrink)

In bilateral logic formulas are signed by + and –, indicating the speech acts assertion and denial. I argue that making an assumption is also speech act. Speech acts cannot be embedded within other speech acts. Hence we cannot make sense of the notion of making an assumption in bilateral logic. Attempts to solve this problem are considered and rejected.

Within contemporary metaethics, it is widely held that there is a “presumption of realism” in moral thought and discourse. Anti-realist views, like error theory and expressivism, may have certain theoretical considerations speaking in their favor, but our pretheoretical stance with respect to morality clearly favors objectivist metaethical views. This article argues against this widely held view. It does so by drawing from recent discussions about so-called “subjective attitude verbs” in linguistics and philosophy of language. Unlike pretheoretically objective predicates (e.g., “is (...) made of wood”, “is 185 cm tall”), moral predicates embed felicitously under subjective attitude verbs like the English “find”. Moreover, it is argued that the widespread notion that moral discourse bears all the marks of fact-stating discourse is rooted in a blinkered focus on examples from English. Cross-linguistic considerations suggest that subjective attitude verbs are actually the default terms by which we ascribe moral views to people. Impressions to the contrary in English have to do with some unfortunate quirks of the term “think”. (shrink)

Ian Rumfitt has proposed systems of bilateral logic for primitive speech acts of assertion and denial, with the purpose of ‘exploring the possibility of specifying the classically intended senses for the connectives in terms of their deductive use’ : 810f). Rumfitt formalises two systems of bilateral logic and gives two arguments for their classical nature. I assess both arguments and conclude that only one system satisfies the meaning-theoretical requirements Rumfitt imposes in his arguments. I then formalise an intuitionist system of (...) bilateral logic which also meets those requirements. Thus Rumfitt cannot claim that only classical bilateral rules of inference succeed in imparting a coherent sense onto the connectives. My system can be extended to classical logic by adding the intuitionistically unacceptable half of a structural rule Rumfitt uses to codify the relation between assertion and denial. Thus there is a clear sense in which, in the bilateral framework, the difference between classicism and intuitionism is not one of the rules of inference governing negation, but rather one of the relation between assertion and denial. (shrink)

In "Rethinking Sadomasochism," Patrick Hopkins challenges the "radical" feminist claim that sadomasochism is incompatible with feminism. He does so by appeal to the notion of "simulation." I argue that Hopkins's conclusions are generally right, but they cannot be inferred from his "simulation" argument. I replace Hopkins's "simulation" with Kendall Walton's more sophisticated theory of "make-believe." I use this theory to better argue that privately conducted sadomasochism is compatible with feminism.

A well-known theory about under which circumstances a statement is true in a fiction is The Reality Principle, which originate in the work of David Lewis: (RP) Where p1... pn are the primary fictional truths of a fiction F , it is true in F that q iff the following holds: were p1 ... pn the case, q would have been the case (Walton 1990: 44). RP has been subjected to a number of counterexamples, up to a point where, in (...) the words of Stacie Friend “it is widely recognized that the Reality Principle […] cannot be a universal inference rule for implied story-truths” (Friend 2017: 33). This chapter argues that the strength of these counterexamples is widely overestimated, and that they do not, on closer scrutiny, constitute reasons for rejecting RP. (shrink)

This paper considers whether incompatibilism, the view that negation is to be explained in terms of a primitive notion of incompatibility, and Fregeanism, the view that arithmetical truths are analytic according to Frege’s definition of that term in §3 of Foundations of Arithmetic, can both be upheld simultaneously. Both views are attractive on their own right, in particular for a certain empiricist mind-set. They promise to account for two philosophical puzzling phenomena: the problem of negative truth and the problem of (...) epistemic access to numbers. For an incompatibilist, proofs of numerical non-identities must appeal to primitive incompatibilities. I argue that no analytic primitive incompatibilities are forthcoming. Hence incompatibilists cannot be Fregeans. (shrink)

This is a commentary on MM McCabe's "First Chop your logos... Socrates and the sophists on language, logic, and development". In her paper MM analyses Plato's Euthydemos, in which Plato tackles the problem of falsity in a way that takes into account the speaker and complements the Sophist's discussion of what is said. The dialogue looks as if it is merely a demonstration of the silly consequences of eristic combat. And so it is. But a main point of MM's paper (...) is that there is serious philosophy in the Euthydemos, too. MM argues that to counter the sophist brothers Euthydemos and Dionysodoros, Socrates points out that that there are different aspects to the verb 'to say' that run in parallel to the different aspects of the very 'to learn'. So just as there is continuity rather than ambiguity between 'to learn' and 'to understand', so there is continuity between the different aspects of saying. Thus Socrates puts forward a teleological account of both learning and meaning. Following up on some of MM's thoughts, I argue that the sophists subscribe, despite appearance, to a theory of meaning that respects serious and widely accepted philosophical theses on meaning. -/- Forthcoming in the Australasian Philosophical Review. The curator of the volume is Fiona Leigh, and the committee also has Hugh Benson and Tim Clarke. You can find MM's paper as well as the commentaries by Nicholas Denyer and Russell E. Jones and Ravi Sharma (and myself) by registering. (shrink)

Bilateralists hold that the meanings of the connectives are determined by rules of inference for their use in deductive reasoning with asserted and denied formulas. This paper presents two bilateral connectives comparable to Prior's tonk, for which, unlike for tonk, there are reduction steps for the removal of maximal formulas arising from introducing and eliminating formulas with those connectives as main operators. Adding either of them to bilateral classical logic results in an incoherent system. One way around this problem is (...) to count formulas as maximal that are the conclusion of reductio and major premise of an elimination rule and to require their removability from deductions. The main part of the paper consists in a proof of a normalisation theorem for bilateral logic. The closing sections address philosophical concerns whether the proof provides a satisfactory solution to the problem at hand and confronts bilateralists with the dilemma that a bilateral notion of stability sits uneasily with the core bilateral thesis. (shrink)

In this paper, I'll present a general way of "reading off" introduction/elimination rules from elimination/introduction rules, and define notions of harmony and stability on the basis of it.

The outcomes of sports and competitive games excite intense emotions in many people, even when those same people acknowledge that those outcomes are of trifling importance. I call this incongruity between the judged importance of the outcome and the intense reactions it provokes the Puzzle of Sport. The puzzle can be usefully compared to another puzzle in aesthetics: the Paradox of Fiction, which asks how it is we become emotionally caught up with events and characters we know to be unreal. (...) In this article, I examine the prospects of understanding our engagement with competitive games on the model of our engagement with works of fiction, thus enabling analogous explanations for both puzzles. I show that there are significant problems with such an approach and offer an alternative, mobilizing ideas from David Velleman and Thomas Nagel, that appeals to the volatility of our motivational attitudes. (shrink)

This paper presents a way of formalising definite descriptions with a binary quantifier ι, where ιx[F, G] is read as ‘The F is G’. Introduction and elimination rules for ι in a system of intuitionist negative free logic are formulated. Procedures for removing maximal formulas of the form ιx[F, G] are given, and it is shown that deductions in the system can be brought into normal form.

We investigated whether mathematicians typically agree about the qualities of mathematical proofs. Between-mathematician consensus in proof appraisals is an implicit assumption of many arguments made by philosophers of mathematics, but to our knowledge the issue has not previously been empirically investigated. We asked a group of mathematicians to assess a specific proof on four dimensions, using the framework identified by Inglis and Aberdein (2015). We found widespread disagreement between our participants about the aesthetics, intricacy, precision and utility of the proof, (...) suggesting that a priori assumptions about the consistency of mathematical proof appraisals are unreasonable. (shrink)

This paper studies a formalisation of intuitionistic logic by Negri and von Plato which has general introduction and elimination rules. The philosophical importance of the system is expounded. Definitions of ‘maximal formula’, ‘segment’ and ‘maximal segment’ suitable to the system are formulated and corresponding reduction procedures for maximal formulas and permutative reduction procedures for maximal segments given. Alternatives to the main method used are also considered. It is shown that deductions in the system convert into normal form and that deductions (...) in normal form have the subformula property. (shrink)

This paper considers a formalisation of classical logic using general introduction rules and general elimination rules. It proposes a definition of ‘maximal formula’, ‘segment’ and ‘maximal segment’ suitable to the system, and gives reduction procedures for them. It is then shown that deductions in the system convert into normal form, i.e. deductions that contain neither maximal formulas nor maximal segments, and that deductions in normal form satisfy the subformula property. Tarski’s Rule is treated as a general introduction rule for implication. (...) The general introduction rule for negation has a similar form. Maximal formulas with implication or negation as main operator require reduction procedures of a more intricate kind not present in normalisation for intuitionist logic. (shrink)

Persons are widely believed to be rational, planning agents that are both author and main character of their life stories. A major goal is to keep these narratives coherent as they unfold, and part of a fulfilled life allegedly stems from this coherence. My aim is to challenge these convictions by considering two related claims about persons and their lives. Contrary to the widespread theoretical conviction in philosophy of mind and action, persons are fundamentally emotional and affective rather than rational (...) and deliberative beings. And so, on a practical level, persons need not constantly aspire to integrate their past, present, and future into a coherent whole in order to live fulfilled lives. Needless to say, I cannot hope to defend these claims and their relation in great detail with a few brief strokes. In addition to theoretical reflections, I discuss some practical implications and potential benefits that come with discarding the daunting task of continuously keeping track of one's life story. Drawing on insights from a contemplative Buddhist tale, I venture that the practice of letting go can break the spell, and give rise to an alleviating source of liberation from life's troubles.Export citation. (shrink)

Sentences containing definite descriptions, expressions of the form ‘The F’, can be formalised using a binary quantifier ι that forms a formula out of two predicates, where ιx[F, G] is read as ‘The F is G’. This is an innovation over the usual formalisation of definite descriptions with a term forming operator. The present paper compares the two approaches. After a brief overview of the system INFι of intuitionist negative free logic extended by such a quantifier, which was presented in (...) (Kürbis 2019), INFι is first compared to a system of Tennant’s and an axiomatic treatment of a term forming ι operator within intuitionist negative free logic. Both systems are shown to be equivalent to the subsystem of INFι in which the G of ιx[F, G] is restricted to identity. INFι is then compared to an intuitionist version of a system of Lambert’s which in addition to the term forming operator has an operator for predicate abstraction for indicating scope distinctions. The two systems will be shown to be equivalent through a translation between their respective languages. Advantages of the present approach over the alternatives are indicated in the discussion. (shrink)

The fundamental assumption of Dummett’s and Prawitz’ proof-theoretic justification of deduction is that ‘if we have a valid argument for a complex statement, we can construct a valid argument for it which finishes with an application of one of the introduction rules governing its principal operator’. I argue that the assumption is flawed in this general version, but should be restricted, not to apply to arguments in general, but only to proofs. I also argue that Dummett’s and Prawitz’ project of (...) providing a logical basis for metaphysics only relies on the restricted assumption. (shrink)

Molnar argues that the problem of truthmakers for negative truths arises because we tend to accept four metaphysical principles that entail that all negative truths have positive truthmakers. This conclusion, however, already follows from only three of Molnar´s metaphysical principles. One purpose of this note is to set the record straight. I provide an alternative reading of two of Molnar´s principles on which they are all needed to derive the desired conclusion. Furthermore, according to Molnar, the four principles may be (...) inconsistent. By themselves, however, they are not. The other purpose of this note is to propose some plausible further principles that, when added to the four metaphysical theses, entail a contradiction. (shrink)

Bilateralists, who accept that there are two primitive speech acts, assertion and denial, can offer an attractive definition of consequence: Y follows from X if and only if it is incoherent to assert all formulas X and to deny all formulas Y. The present paper argues that this definition has consequences many will find problematic, amongst them that truth coincides with assertibility. Philosophers who reject these consequences should therefore reject this definition of consequence.

Thought experiments that concoct bizarre possible world modalities are standard fare in debates on personal identity. Appealing to intuitions raised by such evocations is often taken to settle differences between conflicting theoretical views that, albeit, have practical implications for ethical controversies of personal identity in health care. Employing thought experiments that way is inadequate, I argue, since personhood is intrinsically linked to constraining facts about the actual world. I defend a moderate modal skepticism according to which intuiting across conceptually incongruent (...) worlds constitutes ‘invalid intuitioninferences’—i.e., carrying over intuitions gathered from facts about possible worlds that are at odds with facts about the actual world, for the purpose of making claims about real-life persons and their identity, leads to conceptual incongruences. Such a methodological fallout precludes accurate, informative judgments about personal identity in the actual world, calling into question the adequacy of thought experimental considerations for potential real world applications in medical ethics. (shrink)

This paper presents rules of inference for a binary quantifier I for the formalisation of sentences containing definite descriptions within intuitionist positive free logic. I binds one variable and forms a formula from two formulas. Ix[F, G] means ‘The F is G’. The system is shown to have desirable proof-theoretic properties: it is proved that deductions in it can be brought into normal form. The discussion is rounded up by comparisons between the approach to the formalisation of definite descriptions recommended (...) here and the more usual approach that uses a term-forming operator ι, where ιxF means ‘the F’. (shrink)

Rumfitt has given two arguments that in unilateralist verificationist theories of meaning, truth collapses into correct assertibility. In the present paper I give similar arguments that show that in unilateral falsificationist theories of meaning, falsehood collapses into correct deniability. According to bilateralism, meanings are determined by assertion and denial conditions, so the question arises whether it succumbs to similar arguments. I show that this is not the case. The final section considers the question whether a principle central to Rumfitt's first (...) argument, ‘It is assertible that if and only if it is assertible that it is assertible that ’, is one that bilateralists can reject, and concludes that they cannot. It follows that the logic of assertibility and deniability, according to a result by Williamson, is the little known modal logic K4 studied by Sobociński. The paper ends with a plaidoyer for bilateralists to adopt this logic. (shrink)

The problem of negative truth is the problem of how, if everything in the world is positive, we can speak truly about the world using negative propositions. A prominent solution is to explain negation in terms of a primitive notion of metaphysical incompatibility. I argue that if this account is correct, then minimal logic is the correct logic. The negation of a proposition A is characterised as the minimal incompatible of A composed of it and the logical constant ¬. A (...) rule based account of the meanings of logical constants that appeals to the notion of incompatibility in the introduction rule for negation ensures the existence and uniqueness of the negation of every proposition. But it endows the negation operator with no more formal properties than those it has in minimal logic. (shrink)

This paper draws attention to a proof of the necessity of identity given by Arthur Prior. In its simplicity, it is comparable to a proof of Quine's, popularised by Kripke, but it is slightly different. Prior's Polish notation is transcribed into a more familiar idiom. Prior's proof is followed by a proof of the necessity of difference, possibly the first such proof in the literature, which is also repeated here and transcribed. The paper concludes with a brief discussion of Prior's (...) views on identity and difference over time. (shrink)

This paper considers proof-theoretic semantics for necessity within Dummett's and Prawitz's framework. Inspired by a system of Pfenning's and Davies's, the language of intuitionist logic is extended by a higher order operator which captures a notion of validity. A notion of relative necessary is defined in terms of it, which expresses a necessary connection between the assumptions and the conclusion of a deduction.

There is widespread agreement that while on a Dummettian theory of meaning the justified logic is intuitionist, as its constants are governed by harmonious rules of inference, the situation is reversed on Huw Price's bilateralist account, where meanings are specified in terms of primitive speech acts assertion and denial. In bilateral logics, the rules for classical negation are in harmony. However, as it is possible to construct an intuitionist bilateral logic with harmonious rules, there is no formal argument against intuitionism (...) from the bilateralist perspective. Price gives an informal argument for classical negation based on a pragmatic notion of belief, characterised in terms of the differences they make to speakers' actions. The main part of this paper puts Price's argument under close scrutiny by regimenting it and isolating principles Price is committed to. It is shown that Price should draw a distinction between A or ¬A making a difference. According to Price, if A makes a difference to us, we treat it as decidable. This material allows the intuitionist to block Price's argument. Abandoning classical logic also brings advantages, as within intuitionist logic there is a precise meaning to what it might mean to treat A as decidable: it is to assume A ∨ ¬A. (shrink)

This short paper has two loosely connected parts. In the first part, I discuss the difference between classical and intuitionist logic in relation to different the role of hypotheses play in each logic. Harmony is normally understood as a relation between two ways of manipulating formulas in systems of natural deduction: their introduction and elimination. I argue, however, that there is at least a third way of manipulating formulas, namely the discharge of assumption, and that the difference between classical and (...) intuitionist logic can be characterised as a difference of the conditions under which discharge is allowed. Harmony, as ordinarily understood, has nothing to say about discharge. This raises the question whether the notion of harmony can be suitably extended. This requires there to be a suitable fourth way of manipulating formulas that discharge can stand in harmony to. The question is whether there is such a notion: what might it be that stands to discharge of formulas as introduction stands to elimination? One that immediately comes to mind is the making of assumptions. I leave it as an open question for further research whether the notion of harmony can be fruitfully extended in the way suggested here. In the second part, I discuss bilateralism, which proposes a wholesale revision of what it is that is assumed and manipulated by rules of inference in deductions: rules apply to speech acts – assertions and denials – rather than propositions. I point out two problems for bilateralism. First, bilaterlists cannot, contrary to what they claim to be able to do, draw a distinction between the truth and assertibility of a proposition. Secondly, it is not clear what it means to assume an expression such as '+ A' that is supposed to stand for an assertion. Worse than that, it is plausible that making an assumption is a particular speech act, as argued by Dummett (Frege: Philosophy of Language, p.309ff). Bilaterlists accept that speech acts cannot be embedded in other speech acts. But then it is meaningless to assume + A or − A. (shrink)

In 2009, a law was passed in the Danish parliament, according to which judges cannot wear religious symbols in courts of law. First, I trace the development of this legislation from resistance to Muslim religious practices on the nationalist right to ideas in mainstream Danish politics about secularism and state neutrality – a process I refer to as ‘liberalization’. Second, I consider the plausibility of such liberal justifications for restrictions on religious symbols in the public sphere and, in particular, for (...) the ban on the wearing of religious symbols by judges. I argue that such justifications are flawed and so are not plausible corollaries of anti-Islamic justifications originating on the nationalist right. (shrink)

Review of Bob Hale's "Necessary Beings: An Essay on Ontology, Modality, and the Relations Between Them". Oxford: Oxford University Press 2013, ISBN 9780199669578.

Hossack's 'The Metaphysics of Knowledge' develops a theory of facts, entities in which universals are combined with universals or particulars, as the foundation of his metaphysics. While Hossack argues at length that there must be negative facts, facts in which the universal 'negation' is combined with universals or particulars, his conclusion that there are also general facts, facts in which the universal 'generality' is combined with universals, is reached rather more swiftly. In this paper I present Hossack with three arguments (...) for his conclusion. They all draw, as does Hossack's theory of facts, on views Russell expressed in various writings. Two arguments are based on Russell's explanation of universals as aspects of resemblance; the third on Russell's observation that general propositions do not follow logically from exclusively particular premises. Comparison with other metaphysics of generality show them to be wanting and Russell's and Hossack's accounts superior. (shrink)

This paper presents rules in sequent calculus for a binary quantifier I to formalise definite descriptions: Ix[F, G] means ‘The F is G’. The rules are suitable to be added to a system of positive free logic. The paper extends the proof of a cut elimination theorem for this system by Indrzejczak by proving the cases for the rules of I. There are also brief comparisons of the present approach to the more common one that formalises definite descriptions with a (...) term forming operator. In the final section rules for I for negative free and classical logic are also mentioned. (shrink)

This article is the text of a commentary on a talk delivered by Mark Textor entitled 'Brentano's Positing Theory of Existence' at King's College London in December 2015. It contains ideas on implementing Textor's Neo-Brentanian theory of existence in a natural deduction proof system for negative free logic.

This paper presents a sequent calculus and a dual domain semantics for a theory of definite descriptions in which these expressions are formalised in the context of complete sentences by a binary quantifier I. I forms a formula from two formulas. Ix[F, G] means ‘The F is G’. This approach has the advantage of incorporating scope distinctions directly into the notation. Cut elimination is proved for a system of classical positive free logic with I and it is shown to be (...) sound and complete for the semantics. The system has a number of novel features and is briefly compared to the usual approach of formalising ‘the F ’ by a term forming operator. It does not coincide with Hintikka’s and Lambert’s preferred theories, but the divergence is well-motivated and attractive. (shrink)

This note corrects an error in my paper 'Normalisation and Subformula Property for a System of Classical Logic with Tarski's Rule' (Archive for Mathematical Logic 61 (2022): 105-129, DOI 10.1007/s00153-021-00775-6): Theorem 2 is mistaken, and so is a corollary drawn from it as well as a corollary that was concluded by the same mistake. Luckily this does not affect the main result of the paper.

The Introduction to "Knowledge, Number and Reality. Encounters with the Work of Keith Hossack" provides an overview over Hossack's work and the contributions to the volume.

Consider the opening sentence of Tolkien’s The Hobbit: In a hole in the ground there lived a hobbit. By writing this sentence, Tolkien is making a fictional statement. There are two influential views of the nature of such statements. On the pretense view, fictional discourse amounts to pretend assertions. Since the author is not really asserting, but merely pretending, a statement such as Tolkien’s is devoid of illocutionary force altogether. By contrast, on the alternative make-believe view, fictional discourse prescribes that (...) the reader make-believe the content of the statement. In this paper, we argue that neither of these views is satisfactory. They both fail to distinguish the linguistic act of creating the fiction, for instance Tolkien writing the sentence above, from the linguistic act of reciting it, such as reading The Hobbit out loud for your children. As an alternative to these views, we propose that the essential feature of the author’s speech act is its productive character, that it makes some state of affairs obtain in the fiction. Tolkien’s statement, we argue, has the illocutionary force of a declaration. (shrink)

Berkeley’s ‘esse is percipi’ has been criticized for implying epistemological solipsism, the main argument being that different minds cannot harbor numerically one and the same idea. Similarly, C. J. Boström, the dominating Swedish philosopher in the nineteenth century, was early scorned because his principle of esse est percipi allegedly contradicts the simultaneous claim that two spirits can perceive the same thing under qualitatively different appearances. Whereas the criticism against Berkeley is here regarded as valid, it is argued that Boström successfully (...) defended himself by employing a dual concept of meaning, resembling Frege’s Sinn and Bedeutung some thirty years later, and by postulating an ontology that permits human minds to share in the divine ideas that constitute reality. (shrink)

Throughout these last few decades, phenomenology and modern physics have slowly started to approach each other in order to bridge the gap between subjective and objective. In this thesis I aim to show an approach done with the help of Karen Barad's agential realism; a quantum interpretation enabling us to better understand and analyse our complex world, as well as our perception of it. Taking inspiration from new materialism, phenomenology, and physics, I see a need to properly leave discrete dualism (...) behind, in order to be able to describe cultural and material structures as continuous manifolds. Instead of endlessly searching for their binary and changeless parts. (shrink)

Without directly addressing the Demarcation Problem for logic—the problem of distinguishing logical vocabulary from others—we focus on distinctive aspects of logical vocabulary in pursuit of a second goal in the philosophy of logic, namely, proposing criteria for the justification of logical rules. Our preferred approach has three components. Two of these are effectively Belnap’s, but with a twist. We agree with Belnap’s response to Prior’s challenge to inferentialist characterisations of the meanings of logical constants. Belnap argued that for a logical (...) constant to exist, its rules must be conservative over a previously given consequence relation and guarantee the uniqueness of the constant. The twist is that we require logical vocabulary to be provably conservative, not over a previously given formal consequence relation, but over a previously given meaningful vocabulary of a language. Uniqueness is also a feature defined in terms of provability: if two syntactically distinguished expressions are governed by the same rules, then formulas with them as main operators are interderivable. Belnap’s criteria are not only those for the existence of a logical constant, but more: they are what distinguishes logical vocabulary from all other expressions. It is the defining mark of a logical constant that it is provably conservative over the fragment of the language which excludes it and that its rules guarantee its uniqueness. The third component is the topic neutrality of logic. The provable conservativeness of logic over a previously given vocabulary of a language is motivated, in part, by appeal to molecularism in the theory of meaning. Molecularity is a feature endorsed by the theory of meaning as a whole, so it does not distinguish logical constants from other expressions. The same is true for conservativeness. We argue that molecularity, and hence conservativeness, are implicit presuppositions of speakers’ use of language: the addition of new vocabulary to a language is presupposed to be conservative. But this presupposition is one that we should be able reflectively to endorse (such as when attempting a rational reconstruction of the use of the vocabulary). Thus, where conservativeness is found to fail, this defect should be remedied and the use of the vocabulary corrected (as in classical negation) or excised altogether (as in pejoratives). We go on to characterise a notion of topic neutrality, which we argue applies to logical vocabulary. We then note that reflective endorsement of the conservativeness of a topic neutral vocabulary requires a proof that the vocabulary is conservative relative to any base vocabulary. Thus we require that logical vocabulary be demonstrably conservative. Allying this requirement, distinctive of logic, to a general consideration about the commitments of assertion yields a mode of justification for logical constants akin to some conceptions of Harmony, i.e., to the idea that the consequences of assertion of a logical complex need to be warranted by the grounds and ought to be the strongest consequences warranted by the grounds. Intuitionistic logic acquires a somewhat familiar justification but emanating from a new motivation. (shrink)

The book attempts to build a bridge across three cultures: mathematical statistics, quantum theory and chemometrical methods.

Within the interdisciplinary field of new materialism Karen Barad’s theory of agential realism deconstructs our current euro-western metaphysical perception of the world and our existence within it, to then re-build an understanding based on relatively new findings within quantum physics. In this thesis I try to recreate Barad’s theory to see what ethical consequences might come from it. Together with practical examples within the discourse of today’s social world and our global connectedness I hope to create a better understanding of (...) the impact of our actions and being on our culture and what we call the natural world. Removing the unique agency given to human culture and language to instead, with the help of post-humanistic ideas, add agency as a universal enactment rather than an attribute, we should start to see ourselves as active and real parts of the world-building that is our home. One main question that I see arise in the end is: what does responsibility entail when we all are one and the same? (shrink)

In recent literature many theorists, including Eklund (2011), endorse or express sympathy towards the view that the evaluative content of thick terms is not asserted with utterances of sentences containing them but rather part of their secondary content. In this article we discuss a number of features of thick terms which speak against this view. We further argue that these features are not shared by another, recently much-discussed, class of hybrid evaluative terms, so-called slurs, and that the evaluative contents of (...) these might thus very well be secondary. (shrink)