It is known that many relevant logics can be conservatively extended by the truth constant known as the Ackermann constant. It is also known that many relevant logics can be conservatively extended by Boolean negation. This essay, however, shows that a range of relevant logics with the Ackermann constant cannot be conservatively extended by a Boolean negation.

Many relevant logics can be conservatively extended by Boolean negation. Mares showed, however, that E is a notable exception. Mares’ proof is by and large a rather involved model-theoretic one. This paper presents a much easier proof-theoretic proof which not only covers E but also generalizes so as to also cover relevant logics with a primitive modal operator added. It is shown that from even very weak relevant logics augmented by a weak K-ish modal operator, and up to the strong (...) relevant logic R with a S5 modal operator, all fail to be conservatively extended by Boolean negation. The proof, therefore, also covers Meyer and Mares’ proof that NR—R with a primitive S4-modality added—also fails to be conservatively extended by Boolean negation. (shrink)

This paper shows that the relevant logics E and Π′ are strongly sound and complete with regards to a version of the “simplified” Routley-Meyer semantics. Such a semantics for E has been thought impossible. Although it is impossible if an admissible rule of E – the rule of restricted assertion or equivalently Ackermann’s δ-rule – is solely added as a primitiverule, it is very much possible when E is axiomatized in the way Anderson and Belnap did. The simplified semantics for (...) E and Π′ requires unreduced frames. Contra what has been claimed, however, no additional frame component is required over and above what’s required to model other relevant logics such as T and R. It is also shown how to modify the tonicity requirements of theternary relation so as to allow for the standard truth condition for both fusion – the intensional conjunction◦ – as well as the converse conditional ←. (shrink)

This paper gives an account of Anderson and Belnap’s selection criteria for an adequate theory of entailment. The criteria are grouped into three categories: criteria pertaining to modality, those pertaining to relevance, and those related to expressive strength. The leitmotif of both this paper and its prequel is the relevant legitimacy of disjunctive syllogism. Relevant logics are commonly held to be paraconsistent logics. It is shown in this paper, however, that both E and R can be extended to explosive logics (...) which satisfy all of Anderson and Belnap’s selection criteria, provided the truth-constant known as the Ackermann constant is available. One of the selection criteria related to expressive strength is having an “enthymematic” conditional for which a deduction theorem holds. I argue that this allows for a new interpretation of Anderson and Belnap’s take on logical consequence, namely as committing them to pluralism about logical consequence. (shrink)

This paper shows that the relevant logics E and Π′ are strongly sound and complete with regards to a version of the “simplified” Routley-Meyer semantics. Such a semantics for E has been thought impossible. Although it is impossible if an admissible rule of E  the rule of restricted assertion or equivalently Ackermann’s δ-rule  is solely added as a primitive rule, it is very much possible when E is axiomatized in the way Anderson and Belnap did. The simplified semantics (...) for E and Π′ requires unreduced frames. Contra what has been claimed, however, no additional frame component is required over and above what’s required to model other relevant logics such as T and R. It is also shown how to modify the tonicity requirements of the ternary relation so as to allow for the standard truth condition for both fusion – the intensional conjunction ◦ – as well as the converse conditional ←. (shrink)

This paper shows how to conservatively extend theories formulated in non-classical logics such as the Logic of Paradox, the Strong Kleene Logic and relevant logics with Skolem functions. Translations to and from the language extended by Skolem functions into the original one are presented and shown to preserve derivability. It is also shown that one may not always substitute s=f(t) and A(t, s) even though A determines the extension of a function and f is a Skolem function for A.

Relevant logics have traditionally been viewed as paraconsistent. This paper shows that this view of relevant logics is wrong. It does so by showing forth a logic which extends classical logic, yet satisfies the Entailment Theorem as well as the variable sharing property. In addition it has the same S4-type modal feature as the original relevant logic E as well as the same enthymematical deduction theorem. The variable sharing property was only ever regarded as a necessary property for a logic (...) to have in order for it to not validate the so-called paradoxes of implication. The Entailment Theorem on the other hand was regarded as both necessary and sufficient. This paper shows that the latter theorem also holds for classical logic, and so cannot be regarded as a sufficient property for blocking the paradoxes. The concept of suppression is taken up, but shown to be properly weaker than that of variable sharing. (shrink)

Ackermann’s motivational spin on his theory of rigorous implication is analyzed and it is shown to contain en equivalent idea to Plumwood’s notion of suppression freedom. The formal properties these ideas back turn out to be properly weaker than Belnap’s variable sharing property, but it is shown that they can be strengthen in various ways. Some such strengthenings, it is shown, yield properties which are equivalent to Belnap’s, and thus provide for new ways of motivating Belnap’s fundamental relevance principle.

We argue that people may resist temptations not only with the aim of acquiring more self-control, but also because they want to convince others that they are patient and already possess self-control.

Artificial intelligence receives attention in media as well as in academe and business. In media coverage and reporting, AI is predominantly described in contrasted terms, either as the ultimate solution to all human problems or the ultimate threat to all human existence. In academe, the focus of computer scientists is on developing systems that function, whereas philosophy scholars theorize about the implications of this functionality for human life. In the interface between technology and philosophy there is, however, one imperative aspect (...) of AI yet to be articulated: how do intelligent systems make inferences? We use the overarching concept “Artificial Intelligent Behaviour” which would include both cognition/processing and judgment/behaviour. We argue that due to the complexity and opacity of artificial inference, one needs to initiate systematic empirical studies of artificial intelligent behavior similar to what has previously been done to study human cognition, judgment and decision making. This will provide valid knowledge, outside of what current computer science methods can offer, about the judgments and decisions made by intelligent systems. Moreover, outside academe—in the public as well as the private sector—expertise in epistemology, critical thinking and reasoning are crucial to ensure human oversight of the artificial intelligent judgments and decisions that are made, because only competent human insight into AI-inference processes will ensure accountability. Such insights require systematic studies of AI-behaviour founded on the natural sciences and philosophy, as well as the employment of methodologies from the cognitive and behavioral sciences. (shrink)

Democratic backsliding and autocratisation tendencies raise the question of what liberal democracy can do to defend itself. Of particular concern are populists, who are often perceived to have an ambiguous commitment to the principles of liberal democracy. The defence of liberal democracy has often been conceived in legal terms, for example, with party bans and propaganda restrictions. However, legal means are criticized for being elitist because they are directed against irrational and emotionally driven masses and because they allegedly violate the (...) very values that they are supposed to protect by limiting the democratic freedom of some groups. Instead, critics have proposed cultural and socio-economic means as non-elitist and non-exclusionary alternatives more in line with the values of democracy. This article discusses whether the employment of cultural and socio-economic means against groups – in casu populists – who are perceived as a challenge to liberal democracy can avoid the charge of elitism and exclusion by analysing whether these means are consistent with the publicity constraint. It finds that the use of education and money to defend democracy against such groups relies on a form of elitism and exclusion similar to the one that the defence by legal means is charged with. (shrink)

This chapter draws on Ayn Rand's esthetic discourse, especially her essay collection The Romantic Manifesto: A Philosophy of Literature and her lecture course on fiction‐writing, edited and published as The Art of Fiction: A Guide for Writers and Readers. First, it looks briefly at Romanticism in its historical context. Next, the chapter discusses how plot enables a writer to show the events of a story as following logically from the values and premises of the characters, and how this method implies (...) a specific approach to characterization. Then, the chapter looks at plot in relation to a story's theme; to the author's projection of his/her own unique values and personality; and to the distinctive use of imagination typical of Romantic art. Finally, it addresses the question of how Rand's advocacy of plot relates to her concept of objectivity. (shrink)

This introduction describes the background and reasons why the Mercator-Hondius atlas analysed in this issue became part of the library collection of the Donner Institute.

Two Hilbert calculi in the use-restricted relevance tradition of Anderson and Belnap are presented. One yields Anderson and Belnap's conjunctive version of the so-called ``entailment theorem,'' whereas the other yields the implication-iterated version. In contrast to previous such use-restricted calculi, those presented in this paper apply to arbitrary strengthenings of the weak contractionless logic B without need for modifying the use-conditions. As such they help to identify the core idea of the ``use-account'' of relevance.

Lautemann et al. (1995) gave a descriptive characterisation of the class of context-free languages, showing that a language is context-free iff it is definable as the set of words satisfying some sentence of a particular logic (fragment) over words. The present notes discuss how to specialise this result to the class of linear languages. Somewhat surprisingly, what would seem the most straightforward specialisation actually fails, due to the fact that linear grammars fail to admit a Greibach normal form. We identify (...) an alternative specialisation, based on an alternative characterisation of context-free languages, also noted by Lautemann et al. (1995). (shrink)

Name der Zeitschrift: Cognitive Linguistics Jahrgang: 27 Heft: 4 Seiten: 573-585.

This article provides a normative framework for evaluating the moral permissibility of various defences of European Union (EU) values against their violation in EU member states. This requires, first, a coherent interpretation of EU values as the values of liberal democracy; second, a clear notion of when they are violated; third, a theory of how liberal democracy can be defended with measures that are consistent with the values of liberal democracy themselves; and, finally, a discussion of what the EU’s role (...) is in this defence. The article argues that it would be permissible for the EU to combine a number of political, cultural, socio-economic and legal responses in a concentric defence of liberal democracy as long as they respect the separation of powers doctrine and do not rely on problematic notions of collective responsibility. (shrink)

Restall set forth a "consecution" calculus in his "An Introduction to Substructural Logics." This is a natural deduction type sequent calculus where the structural rules play an important role. This paper looks at different ways of extending Restall's calculus. It is shown that Restall's weak soundness and completeness result with regards to a Hilbert calculus can be extended to a strong one so as to encompass what Restall calls proofs from assumptions. It is also shown how to extend the calculus (...) so as to validate the metainferential rule of reasoning by cases, as well as certain theory-dependent rules. (shrink)

This paper presents a range of new triviality proofs pertaining to naïve truth theory formulated in paraconsistent relevant logics. It is shown that excluded middle together with various permutation principles such as A → (B → C)⊩B → (A → C) trivialize naïve truth theory. The paper also provides some new triviality proofs which utilize the axioms ((A → B)∧ (B → C)) → (A → C) and (A → ¬A) → ¬A, the fusion connective and the Ackermann constant. An (...) overview over various ways to formulate Leibniz’s law in non-classical logics and two new triviality proofs for naïve set theory are also provided. (shrink)

Val Plumwood and Richard Sylvan argued from their joint paper The Semantics of First Degree Entailment and onward that the variable sharing property is but a mere consequence of a good entailment relation, indeed they viewed it as a mere negative test of adequacy of such a relation, the property itself being a rather philosophically barren concept. Such a relation is rather to be analyzed as a sufficiency relation free of any form of premise suppression. Suppression of premises, therefore, gained (...) center stage. Despite this, however, no serious attempt was ever made at analyzing the concept. This paper shows that their suggestions for how to understand it, either as the Anti-Suppression Principle or as the Joint Force Principle, turn out to yield properties strictly weaker than that of variable sharing. A suggestion for how to understand some of their use of the notion of suppression which clearly is not in line with these two mentioned principles is given, and their arguments to the effect that the Anderson and Belnap logics T, E and R are suppressive are shown to be both technically and philosophically wanting. Suppression-freedom, it is argued, cannot do the job Plumwood and Sylvan intended it to do. (shrink)

Numerous studies have replicated the finding of mentation in both rapid eye movement (REM) and nonrapid eye movement (NREM) sleep. However, two different theoretical models have been proposed to account for this finding: (1) a one-generator model, in which mentation is generated by a single set of processes regardless of physiological differences between REM and NREM sleep; and (2) a two-generator model, in which qualitatively different generators produce cognitive activity in the two states. First, research is reviewed demonstrating conclusively that (...) mentation can occur in NREM sleep; global estimates show an average mentation recall rate of about 50% from NREM sleep – a value that has increased substantially over the years. Second, nine different types of research on REM and NREM cognitive activity are examined for evidence supporting or refuting the two models. The evidence largely, but not completely, favors the two-generator model. Finally, in a preliminary attempt to reconcile the two models, an alternative model is proposed that assumes the existence of covert REM sleep processes during NREM sleep. Such covert activity may be responsible for much of the dreamlike cognitive activity occurring in NREM sleep. Key Words: cognition in sleep; dreaming; NREM sleep; REM sleep; sleep mentation. (shrink)

We previously reported that college students who indicated engaging in frequent dream-enacting behaviors also scored high on a new measure of mirror behaviors, which is the propensity to imitate another person’s emotions or actions. Since dream-enacting behaviors are frequently the culmination of nightmares, one explanation for the observed relationship is that individuals who frequently display mirror behaviors are also prone to nightmares. We used the Mirror Behavior Questionnaire and self-reported frequencies of nightmares to assess this possibility.A sample of 480 students, (...) consisting of 188 males and 292 females enrolled in a first-year university psychology course, participated for course credit. They completed a battery of questionnaires that included the 16-item MBQ, plus an item about nightmare frequency in the past 30 days. NMF scores were split to create low, medium, and high NMF groups.MBQ total scores were significantly higher for female than for male subjects, but an interaction revealed that this was true only for Hi-NMF subjects. MBQ Factor 4, Motor Skill Imitation, paralleled this global interaction for females, whereas MBQ Factor 3, Sleepiness/Anger Contagion, was elevated only for Hi-NMF males. Item analyses indicated that Hi- and Med-NMF females scored higher than Lo-NMF females on the 3 items of Factor 4 that reflect voluntary imitation , as well as on 2 other items that reflect involuntary imitation . Although Hi- and Lo-NMF males differed most clearly on the sleepiness item of Factor 3, all 3 items on this factor are plausibly associated with perception of and response to social threat.Results provide evidence that among females nightmares are associated with voluntary and involuntary mirror behaviors during wakefulness, while among males nightmares are associated with threat-related mirror behaviors during wakefulness. They thus support the possibility that the association between mirror behaviors and dream-enacting behaviors is due to a common mirror neuron mechanism that underlies mirror behaviors and nightmares and that involves motor, rather than emotional, resonance. These results have implications for understanding the comorbidity of nightmares and other pathological symptoms such as imitative suicidal behaviors, the influence of observational learning on dissociative symptomatology, and the predominance of threat and aggression in the dream enacting behaviors of REM sleep behavior disorder. (shrink)

Norwegian philosophy of science right after the war was empiricistic, scientistic, rather undogmatic and heavily dominated by Arne Næss. The positivistic conception of science has been severely criticized in the last two decades, and the attempts to find viable alternatives have led to a broadening of the perspective, philosophically as well as scientifically. This survey tries to map the main lines of that development. After an account of the rise and fall of Næss' programme for a behaviouristic theory of science, (...) we outline first the development of the internal philosophical critique and then the parallel story on the social science scene. (shrink)

This paper argues against Jon Elster's contention that there is a fundamentalincompatibility between, on one hand, autonomy and rationality and, on theother hand, adaptation to conditions of one's existence in the sense that one'sdesires or preferences are adjusted to what it is possible to achieve. While thefirst part of the paper more narrowly concentrated on Elster's discussion ofthese ideas, this second part goes on to a more general discussion of the conceptof rationality. On the basis of this discussion, it is (...) claimed that Elster's conclusionsconcerning autonomy and adaptation are premised on a defective conceptionof human experience and rationality. Moreover, the claim is made that thesedefects are also characteristic of "rational choice theory" more generally. (shrink)

Many relevant logics are conservatively extended by Boolean negation. Not all, however. This paper shows an acute form of non-conservativeness, namely that the Boolean-free fragment of the Boolean extension of a relevant logic need not always satisfy the variable-sharing property. In fact, it is shown that such an extension can in fact yield classical logic. For a vast range of relevant logic, however, it is shown that the variable-sharing property, restricted to the Boolean-free fragment, still holds for the Boolean extended (...) logic. (shrink)

Cheyne and Girard characterize felt presence during sleep paralysis attacks as a pre-hallucinatory expression of a threat-activated vigilance system. While their results may be consistent with this interpretation, they are nonetheless correlational and do not address a parsimonious alternative explanation. This alternative stipulates that FP is a purely spatial, hallucinatory form of a common cognitive phenomenon—social imagery—that is often, but not necessarily, linked with threat and fear and that may induce distress among susceptible individuals. The occurrence of both fearful and (...) non-fearful FPs in a multiplicity of situations other than sleep paralysis attacks supports the notion that FPs are hallucinatory variants of social imagery and that they are not necessarily bound to threat-activated vigilance. Evidence linking FPs with anxiety disorders supports the notion that the distress they evoke may be mediated by a more general affective distress personality factor. To illustrate the predominantly spatial character of FP hallucinations, similarities between FP and phantom limbs are summarized and the possibility that these two phenomena are parallel expressions of a mirror neuron system is considered. (shrink)

Purpose: To survey the attitudes of the general public in Sweden to biobank research and to discuss the findings in the light of some well-known ethical principles.Methods: A questionnaire was used to survey the opinions of the general public in Sweden, and an ethical analysis (using the principles of autonomy, non-maleficence, beneficence and justice) was performed to discuss the possible conditions of such research.Findings: Between 3 and 9% answered that they did not want their samples to be collected and stored (...) in a biobank. Many respondents required information about the purpose of the research and wanted to be able to consent or refuse. About one third of the respondents said they would have answered differently if financial gain was involved and those who commented indicated a more negative attitude. The principle of autonomy maintains that the right to self-determination should be respected, and the principles of non-maleficence and beneficence that the probable harms and benefits resulting from a particular project by using samples from a biobank should be balanced. The general public disagree about how these principles are to be balanced. Interpretation: In the light of the findings different interpretations of the situation as well as possible alternatives are discussed in this paper. (shrink)

Journal Name: Semiotica Issue: Ahead of print.

Priest argued in Fusion and Confusion (Priest in Topoi 34(1):55–61, 2015a) for a new concept of logical consequence over the relevant logic B, one where premises my be “confused” together. This paper develops Priest’s idea. Whereas Priest uses a substructural proof calculus, this paper provides a Hilbert proof calculus for it. Using this it is shown that Priest’s consequence relation is weaker than the standard Hilbert consequence relation for B, but strictly stronger than Anderson and Belnap’s original relevant notion of (...) consequence. Unlike the latter, however, Priest’s consequence relation does not satisfy a variant of the variable sharing property. This paper shows that how it can be modified so as to do so. Priest’s consequence relation turns out to be surprisingly weak in some respects. The prospects of strengthening it is raised and discussed in a broader philosophical context. (shrink)

This essay discusses rules and semantic clauses relating to Substitution—Leibniz’s law in the conjunctive-implicational form s=t ∧ A(s) → A(t)—as these are put forward in Priest’s books "In Contradiction" and "An Introduction to Non-Classical Logic: From If to Is." The stated rules and clauses are shown to be too weak in some cases and too strong in others. New ones are presented and shown to be correct. Justification for the various rules are probed and it is argued that Substitution ought (...) to fail. (shrink)