Sensory substitution devices are a type of sensory prosthesis that (typically) convert visual stimuli transduced by a camera into tactile or auditory stimulation. They are designed to be used by people with impaired vision so that they can recover some of the functions normally subserved by vision. In this chapter we will consider what philosophers might learn about the nature of the senses from the neuroscience of sensory substitution. We will show how sensory substitution devices work by exploiting the cross-modal (...) plasticity of sensory cortex: the ability of sensory cortex to pick up some types of information about the external environment irrespective of the nature of the sensory inputs it is processing. We explore the implications of cross-modal plasticity for theories of the senses that attempt to make distinctions between the senses on the basis of neurobiology. (shrink)

Many philosophers use findings about sensory substitution devices in the grand debate about how we should individuate the senses. The big question is this: Is “vision” assisted by (tactile) sensory substitution really vision? Or is it tactile perception? Or some sui generis novel form of perception? My claim is that sensory substitution assisted “vision” is neither vision nor tactile perception, because it is not perception at all. It is mental imagery: visual mental imagery triggered by tactile sensory stimulation. But it (...) is a special form of mental imagery that is triggered by corresponding sensory stimulation in a different sense modality, which I call “multimodal mental imagery.”. (shrink)

In the substitutional framework, validity is truth under all substitutions of the nonlogical vocabulary. I develop a theory where □ is interpreted as substitutional validity. I show how to prove soundness and completeness for common modal calculi using this definition.

It is hoped that modern sensory substitution and augmentation devices will be able to replace or expand our senses. But to what extent has this been achieved to date? To what extent are the experiences created by sensory substitution devices like the sensory experiences that we are trying to replace? To what extent can we augment people’s senses providing them with new information and new experiences? The first aim of this introduction is to delve deeply into this question to discover (...) the usefulness of these devices, to outline the different sorts of experience that might be created, and what the evidence tells us about these experiences. While there are some reasons to be hopeful about the powers of sensory substitution devices, there are also reasons to wonder whether they will ever really have the practical applications that we hope they might have. The second aim is to look to see whether the study of modern sensory substitution and augmentation devices can shed light on the nature of our senses and perception in general. Much of the philosophical, psychological, and neuroscientific work that takes place concerning sensory substitution and augmentation is keenly aware of the possibility that it might help our understanding and it seeks to comprehend many different aspects of perception. (shrink)

An increasing amount of twenty-first century metaphysics is couched in explicitly hyperintensional terms. A prerequisite of hyperintensional metaphysics is that reality itself be hyperintensional: at the metaphysical level, propositions, properties, operators, and other elements of the type hierarchy, must be more fine-grained than functions from possible worlds to extensions. In this paper I develop, in the setting of type theory, a general framework for reasoning about the granularity of propositions and properties. The theory takes as primitive the notion of a (...) substitution on a proposition (property, etc.) and, among other things, uses this idea to elucidate a number of theoretically important distinctions. A class of structures are identified which can be used to model a wide range of positions about the granularity of reality; certain of these structures are seen to receive a natural treatment in the category of M-sets. (shrink)

Sensory substitution devices make use of one substituting modality to get access to environmental information normally accessed through another modality . Based on behavioural and neuroimaging data, some authors have claimed that using a vision-substituting device results in visual perception. Reviewing these data, we contend that this claim is untenable. We argue that the kind of information processed by a SSD is metamodal, so that it can be accessed through any sensory modality and that the phenomenology associated with the use (...) of a SSD is best described in terms of spatial phenomenology, only. (shrink)

One of the central limitations of sensory substitution devices (SSDs) is their inability to reproduce the non-sensory feelings that are normally associated with visual experiences, especially hedonic and aesthetic responses. This limitation is sometimes reported to cause SSD users frustration. To make matters worse, it is unclear that improvements in acuity, bandwidth, or training will resolve the issue. Yet, if SSDs are to actually reproduce visual experience in its fullness, it seems that the reproduction of non-sensory feelings will be of (...) some importance. We offer a novel solution. Researchers can produce hedonic and aesthetic responses by eliciting these feelings artificially, pairing distal objects that should be pleasurable to pleasurable stimulus outputs from the SSD. We outline two strategies for accomplishing this: first, by means of a prefixed, hardwired, association of pleasant distal objects to pleasant stimulus outputs from the SSD; second, by means of a flexible, feedback-based association which creates associations based on a subject-directed matching of distal objects to patterns of stimuli from the SSD which the subject takes to have the corresponding hedonic properties. We evaluate some problems with both strategies, and we argue that the feedback-based strategy is more promising. Researchers can use this strategy to help the blind, allowing them to take pleasure in the objects they perceive using SSDs. (shrink)

We apply Mints’ technique for proving the termination of the epsilon substitution method via cut-elimination to the system of Peano Arithmetic with Transfinite Induction given by Arai.

It is commonly thought that when a patient is unable to make a treatment decision for herself, patient autonomy should be respected by consulting the views of a patient surrogate, normally either the next-of-kin or a person previously designated by the patient. On one view, the task of this surrogate is to make the treatment decision that the patient would have made if competent. But this so-called ‘substituted judgment standard’ (SJS) has come in for has come in for a good (...) deal of criticism recently. For instance, some question whether surrogates are able to reliably predict what the patient would have chosen. Others wonder how respecting a patient's counter-factual, rather than actual, choices is supposed to respect her autonomy. Such concerns have lead some to reject the SJS and argue for alternative characterisations of the role of surrogate decision-makers. (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)

Describes how the author became an on-call substitute teacher in pursuit of the realities of American public education, describing his complex difficulties with helping educate today's students in spite of flawed curriculums and interpersonal challenges.

In this essay, I propose an analysis of Quine’s example ’Giorgione was so-called because of his size’, grounded on the idea of an obstinate demonstrative. In the first sections, I discuss the advantages and drawbacks of the demonstrative and logophoric treatments of ‘so called’, I highlight certain parallelisms with Davidson’s paratactic view of quotation, and I introduce independent considerations in favor of the idea of an obstinate demonstrative. In the second half of my essay, I apply this notion to Quine’s (...) example, and I discuss its consequences with respect to the principle of substitutivity of coreferential singular terms. (shrink)

A substitutional account of logical validity for formal first‐order languages is developed and defended against competing accounts such as the model‐theoretic definition of validity. Roughly, a substitution instance of a sentence is defined as the result of uniformly substituting nonlogical expressions in the sentence with expressions of the same grammatical category and possibly relativizing quantifiers. In particular, predicate symbols can be replaced with formulae possibly containing additional free variables. A sentence is defined to be logically true iff all its substitution (...) instances are satisfied by all variable assignments. Logical consequence is defined analogously. Satisfaction is taken to be a primitive notion and axiomatized.For every set‐theoretic model in the sense of model theory there exists a corresponding substitutional interpretation in a sense to be specified. Conversely, however, there are substitutional interpretations – in particular the ‘intended’ interpretation – that lack a model‐theoretic counterpart. The substitutional definition of logical validity overcomes the weaknesses of more restrictive accounts of substitutional validity; unlike model‐theoretic logical consequence, the substitutional notion is trivially and provably truth preserving. In Kreisel's squeezing argument the formal notion of substitutional validity naturally slots into the place of intuitive validity. (shrink)

This article seeks to consider the ways in which substitutes for religion have been found both through a discussion of the treatment of religion in the classical sociological theories of Weber; Durkheim and Marx and then the way in which in modern societies alternative sets of belief and practices which fulfi l the same function as religion have been developed in the Communist and the postCommunist and Western worlds.

It is widely held that counterfactuals, unlike attitude ascriptions, preserve the referential transparency of their constituents, i.e., that counterfactuals validate the substitution of identicals when their constituents do. The only putative counterexamples in the literature come from counterpossibles, i.e., counterfactuals with impossible antecedents. Advocates of counterpossibilism, i.e., the view that counterpossibles are not all vacuous, argue that counterpossibles can generate referential opacity. But in order to explain why most substitution inferences into counterfactuals seem valid, counterpossibilists also often maintain that counterfactuals (...) with possible antecedents are transparency‐preserving. I argue that if counterpossibles can generate opacity, then so can ordinary counterfactuals with possible antecedents. Utilizing an analogy between counterfactuals and attitude ascriptions, I provide a counterpossibilist‐friendly explanation for the apparent validity of substitution inferences into counterfactuals. I conclude by suggesting that the debate over counterpossibles is closely tied to questions concerning the extent to which counterfactuals are more like attitude ascriptions and epistemic operators than previously recognized. (shrink)

Since several landmark legal decisions in the 1970s and 1980s, substituted judgment has become widely accepted as an approach to decision‐making for incapacitated patients that incorporates their autonomy and interests. Two notable exceptions have been cases involving minors and those involving cognitively or psychiatrically impaired individuals who never previously possessed the ability to contemplate the medical decisions involved in their care. While a best interest standard may have universal merit in pediatric cases, this paper argues that substituted judgement has been (...) rejected too broadly for “never‐capacitated” patients. It then lays out a three‐condition test for using substituted judgment in these cases. For a subset of “never‐capacitated” patients who belong to distinctive religious or cultural communities with clear medical values and have an appropriate surrogate, these values may prove helpful in vindicating the interests of the never‐capacitated and should not be blanketly dismissed. (shrink)

The aim of this article is to provide a plausible conceptual model of a specific use of images described as substitution in recent art-historical literature. I bring to light the largely implicit shared commitments of the art historians’ discussion of substitution, each working as they do in a different idiom, and I draw consequences from these commitments for the concept of substitution by image—the major being the distinction between nonportraying substitution and substitution by portrayal. I then develop an argument that (...) substitution by image in the desired, nonportraying sense needs to be thought of in terms of a figurative representation of an image’s subject as a generic object, what I will call its figurative instantiation. (shrink)

When a user integrates a sensory substitution device into her life, the process involves perceptual learning, that is, ‘relatively long-lasting changes to an organism’s perceptual system that improve its ability to respond to its environment’ (Goldstone 1998: 585). In this paper, I explore ways in which the extensive literature on perceptual learning can be applied to help improve sensory substitution devices. I then use these findings to answer a philosophical question. Much of the philosophical debate surrounding sensory substitution devices concerns (...) what happens after perceptual learning occurs. In particular, should the resultant perceptual experience be classified in the substituted modality (as vision), in the substituting modality (as auditory or tactile), or in a new sense modality? I propose a novel empirical test to help resolve this philosophical debate. (shrink)

In the UK, current policies and services for people with mental disorders, including those with intellectual disabilities (ID), presume that these men and women can, do, and should, make decisions for themselves. The new Mental Capacity Act (England and Wales) 2005 (MCA) sets this presumption into statute, and codifies how decisions relating to health and welfare should be made for those adults judged unable to make one or more such decisions autonomously. The MCA uses a procedural checklist to guide this (...) process of substitute decision-making. The personal experiences of providing direct support to seven men and women with ID living in residential care, however, showed that substitute decision-making took two forms, depending on the type of decision to be made. The first process, ‘strategic substitute decision-making’, paralleled the MCA’s legal and ethical framework, whilst the second process, ‘relational substitute decision-making’, was markedly different from these statutory procedures. In this setting, ‘relational substitute decision-making’ underpinned everyday personal and social interventions connected with residents’ daily living, and was situated within a framework of interpersonal and interdependent care relationships. The implications of these findings for residential services and the implementation of the MCA are discussed. (shrink)

A primary goal of clinical practice is to respect patient autonomy. To promote this goal for patients who have lost the ability to make their own decisions, commentators recommend that surrogates make their treatment decisions based on the substituted judgment standard. This standard is commonly interpreted as directing surrogates to make the decision the patient would have made in the circumstances, if the patient were competent. However, recent commentators have argued that this approach—attempting to make the decision the patient would (...) have made if competent—is theoretically problematic, practically infeasible, and ignores the interests of the patient9s family and loved ones. These commentators conclude that the substituted judgment standard should be revised significantly, or abandoned altogether. While this response would avoid the cited problems, it also would require substantial changes to clinical practice and would raise significant problems of its own. The present paper thus considers the possibility that the criticisms do not point to problems with the substituted judgment standard itself; instead, they point to problems with the way it is most commonly interpreted. This analysis suggests that the substituted judgment standard need not be dramatically revised or abandoned. Instead, it should be interpreted in a way that effectively promotes respect for the autonomy of incompetent patients. The ‘endorsed life’ interpretation described here helps clinicians and surrogates to achieve this important goal. To clarify this approach, we explain how it differs from three other recently proposed alternatives to the standard interpretation of the substituted judgment standard. (shrink)

In their Anachronic Renaissance, Alexander Nagel and Christopher Wood identify two principles upon which, in fifteenth-century Europe, a work of art might establish its validity or authority: substitution and performance. It has become established wisdom that the dual schema of substitution and performance follows Hans Belting's dualism of the medieval cult of the image and the modern aesthetic system of art. This, I submit, is not just a mistake, but also prevents from evaluating one of the book's most ambitious contributions (...) to art-historical theory on its own merits. An analysis of the structure of the claims made by Nagel and Wood brings to light that the two concepts—substitution and performance—do not play the same role as the conceptual pair of Bild and Kunst in Belting's influential work. (shrink)

Goodman and Lederman (2020) argue that the traditional Fregean strategy for preserving the validity of Leibniz’s Law of substitution fails when confronted with apparent counterexamples involving proper names embedded under propositional attitude verbs. We argue, on the contrary, that the Fregean strategy succeeds and that Goodman and Lederman’s argument misfires.

The epsilon substitution method was proposed by D. Hilbert as a tool for consistency proofs. A version for first order predicate logic had been described and proved to terminate in the monograph “Grundlagen der Mathematik”. As far as the author knows, there have been no attempts to extend this approach to the second order case. We discuss possible directions for and obstacles to such extensions.

One of the many important tasks of semantics is to provide an account of the substitution patterns of a language—that is, to furnish an explanation of the conditions under which semantic values of complexes are preserved when components are replaced. The importance of this issue is plain: we only have to recall the debates regarding substitutivity between proponents of direct reference theories and advocates of some version of Fregeanism, as well as the disagreements among different proponents of direct reference (...) theories as regards substitutivity in belief reports. This is why it is important to articulate an acceptable principle of substitution. A traditional statement of the principle of substitution holds that codesignative singular terms should be intersubtitutable salva veritate. In the past I have argued that such a principle is not connected properly to some pretheoretical data about the function of referring terms. In this chapter I argue that such a principle does not gain support either from other, more fundamental, laws. I end by defending the adequacy of a different principle of substitution. (shrink)

The Reference Principle states that co-referring expressions are everywhere intersubstitutable salva congruitate. On first glance, looks like a truism, but a truism with some bite: transforms difficult philosophical questions about co-reference into easy grammatical questions about substitutability. This has led a number of philosophers to think that we can use to make short work of certain longstanding metaphysical debates. For example, it has been suggested that all we need to do to show that the predicate ‘ is a horse’ does (...) not refer to a property is point out that ‘ is a horse’ and ‘the property of being a horse’ are not everywhere intersubstitutable salva congruitate. However, when we understand ‘substitution’ in the simplest and most straightforward way, is no truism; in fact, natural languages are full of counterexamples to the principle. In this paper, I introduce a new notion of substitution, and then develop and argue for a version of that is immune to these counterexamples. Along the way I touch on the following topics: the relation between argument forms and their natural language instances; the reification of sense; the difference between terms and predicates; and the relation between reference and disquotation. I end by arguing that my new version of cannot be used to settle metaphysical debates quite as easily as some philosophers would like. (shrink)

Sensory substitution and augmentation devices are used to replace or enhance one sense by using another. Fiona Macpherson brings together neuroscientists, psychologists and philosophers to focus on the nature of the perceptual experiences, the sensory interactions, and the changes that occur in the mind and brain while using these technologies.

There are two main ways of understanding the function of surrogate decision making in a legal context: the Best Interests Standard and the Substituted Judgment Standard. First, we will argue that the Best Interests Standard is difficult to apply to unconscious patients. Application is difficult regardless of whether they have ever been conscious. Second, we will argue that if we accept the least problematic explanation of how unconscious patients can have interests, we are also obliged to accept that the Substituted (...) Judgment Standard can be coherently applied to patients who have never been conscious at the same extent as the Best Interests Standard. We then argue that acknowledging this result is important in order to show patients respect. (shrink)

AbtractTechnologies both new and old provide us with a wide range of cognitive artifacts that change the structure of our cognitive tasks. After a brief analysis of past classifications of these artifacts, I shall elaborate a new way of classifying them developed by focusing on an aspect that has been previously overlooked, namely the possible relationships between these objects and the cognitive processes they involve. Cognitive artifacts are often considered as objects that simply complement our cognitive capabilities, but this “complementary (...) view” seems to be an oversimplification. Assuming an “interaction-centered approach”, this article identifies three essential ways in which cognitive artifacts carry out their function: complementing, constituting and substituting our cognitive processes, and builds a taxonomy of these objects that is grounded on these relations. In so doing, it also addresses the chaotic set of different micro-functions carried out by cognitive artifacts, which have not thus far been dealt with, sorting these functions into three corresponding categories. The second part of the article analyzes in greater detail how cognitive artifacts work in our cognitive life, identifying a new kind of functions, called semi-proper functions, and providing a new definition of cognitive artifact based on the previous analysis of these objects. (shrink)

Frances Kamm's Principle of Secondary Permissibility specifies a class of exceptions to the general rule not to kill as a means. The principle allows us to harm as a means some of those who would have been otherwise harmed as side effects. ‘For example, suppose it is impermissible to paralyze A's legs as a means to a greater good. It would still be permissible to do this as the alternative to permissibly killing A as a mere indirect side effect.’ I (...) argue that, despite of its great appeal, PSP is incorrect; it is simply not true that the victims of substitutive harm are not worse off than they would otherwise permissibly have been. In fact, there is no moral difference between the purportedly substitutive harm licensed by PSP and the standard sort of harming as means repudiated by nonconsequentialists. (shrink)

In this paper we formulate epsilon substitution method for a theory $\Pi _{2}^{0}$-FIX for non-monotonic $\Pi _{2}^{0}$ inductive definitions. Then we give a termination proof of the H-processes based on Ackermann [1].

We formulate epsilon substitution method for elementary analysisEA (second order arithmetic with comprehension for arithmetical formulas with predicate parameters). Two proofs of its termination are presented. One uses embedding into ramified system of level one and cutelimination for this system. The second proof uses non-effective continuity argument.

Is the brain the biological substrate of consciousness? Most naturalistic philosophers of mind have supposed that the answer must obviously be «yes » to this question. However, a growing number of philosophers working in 4e (embodied, embedded, extended, enactive) cognitive science have begun to challenge this assumption, arguing instead that consciousness supervenes on the whole embodied animal in dynamic interaction with the environment. We call views that share this claim dynamic sensorimotor theories of consciousness (DSM). Clark (2009) a founder and (...) leading proponent of the hypothesis of the extended mind, demurs, arguing that as matter of fact the biology of consciousness doesn’t allow for a brain, body and world boundary crossing architecture. We begin by looking at one of the arguments for DSM, the variable neural correlates argument. We then outline two criticisms that Clark has made of this argument and endorse his criticisms. However we finish up by using the case of sensory substitution to argue that something of this argument for DSM nevertheless survives. We suggest that Clark ought to concede sensory substitution as a case in which the conscious mind extends. (shrink)

I present an analysis according to which the current state of the definition of substitution leads to a contradiction in the system of Transparent Intensional Logic. I entail the contradiction using only the basic definitions of TIL and standard results. I then analyse the roots of the contradiction and motivate the path I take in resolving the contradiction. I provide a new amended definition of collision-less substitution which blocks the contradiction in a non-ad hoc way. I elaborate on the consequences (...) of the amended definition, namely the invalidity of the Church-Rosser theorem. I present a counterexample to the validity of the theorem in TIL with an amended definition of substitution. (shrink)

Fundamental to Quine’s philosophy of logic is the thesis that substitutional quantification does not express existence. This paper considers the content of this claim and the reasons for thinking it is true.

We formulate epsilon substitution method for a theory [Π0 1, Π0 1]-FIX for two steps non-monotonic Π0 1 inductive definitions. Then we give a termination proof of the H-processes based on Ackermann [1].

A refined characterisation of sensory substitution has, as a consequence, that the substituting sense plus sensory substitution device is not always appropriately classified as the substituted sense. As a result, I argue, acclimatisation to a sensory substitution device is plausibly thought of as providing presentations of properties. Externalist accounts of experience together with objectivist characterisations of such properties have the upshot that properties putatively proprietary to a sense modality can be presented in another modality in cases of substitution. I consider (...) three objections to this argument. I close by explaining how reflection on the phenomena of sensory substitution and, in particular, acclimatisation is important for the development of any kind of representationalist or relationist theory of phenomenal properties or, at the very least, suggests we need to refine the idea of certain properties - rather than particular ways in which their presentation is bundled together - being proprietary to the particular senses. (shrink)

The paper presents an alternative substitutional semantics for first-order modal logic which, in contrast to traditional substitutional (or truth-value) semantics, allows for a fine-grained explanation of the semantical behavior of the terms from which atomic formulae are composed. In contrast to denotational semantics, which is inherently reference-guided, this semantics supports a non-referential conception of modal truth and does not give rise to the problems which pertain to the philosophical interpretation of objectual domains (concerning, e.g., possibilia or trans-world identity). The paper (...) also proposes the notion of modality de nomine as an alternative to the denotational notion of modality de re. (shrink)

The \-substitution method is a technique for giving consistency proofs for theories of arithmetic. We use this technique to give a proof of the consistency of the impredicative theory \ using a variant of the cut-elimination formalism introduced by Mints.

If the substitutional interpretation of quantification is tenable, it provides a basis for reinterpreting any formal language-system as nominalist: each substituend for the variables of quantification either designates a concrete object or it is empty.

Expressivism is a blossoming meta-semantic framework sometimes relying on what Carter and Chrisman call “the core expressivist maneuver.” That is, instead of asking about the nature of a certain kind of value, we should be asking about the nature of the value judgment in question. According to expressivists, this question substitution opens theoretical space for the elegant, economical, and explanatorily powerful expressivist treatment of the relevant domain. I argue, however, that experimental work in cognitive psychology can shed light on how (...) the core expressivist maneuver operates at the cognitive level and that this: raises worries about the aptness of the expressivist question substitution and supports an evolutionary debunking argument against expressivism. Since evolutionary debunking arguments are usually run in favor of expressivism, this creates an obvious puzzle for expressivists. I wrap up by briefly responding to the objection that the debunking argument against expressivism overgeneralizes and, therefore, should be rejected. (shrink)

This paper proposes substitutional definitions of logical truth and consequence in terms of relative interpretations that are extensionally equivalent to the model-theoretic definitions for any relational first-order language. Our philosophical motivation to consider substitutional definitions is based on the hope to simplify the meta-theory of logical consequence. We discuss to what extent our definitions can contribute to that.

The doctrine of the atonement is a subject of perpetual curiosity for a number of contemporary theologians. The penal substitution theory of atonement in particular has precipitated a great deal of recent interest, being held up by many Protestants as ‘the’ doctrine of atonement. In this essay, we make a defense against the objection to the Anselmian theory of atonement that is often leveled against it by exponents of the Penal Substitution theory, namely, that Christ’s work does not accomplish anything (...) for those whom it appears he undertakes his atoning work, but merely makes provision for salvation. (shrink)

Russell’s substitutional theory conferred philosophical advantages over the simple type theory it was to emulate. However, it faced propositional paradoxes, and in a 1906 paper “On ‘Insolubilia’ and Their Solution by Symbolic Logic”, he modified the theory to block these paradoxes while preserving Cantor’s results. My aim is to draw out several quandaries for the interpretation of the role of substitution in Russell’s logic. If he was aware of the substitutional (_p_0_a_0) paradox in 1906, why did he advertise “Insolubilia” as (...) a solution to the Epimenides? If he was dissatisfied with the solution, as his correspondence suggests, why did he go on to publish it? Why did substitution reappear with orders in “Mathematical Logic as Based on the Theory of Types” if he had rejected a hierarchy of orders as intolerable? I offer the following as possible explanations: he construed the “logical Epimenides” as a version of the _p_0_a_0 paradox; his dissatisfaction with the “Insolubilia” solution was philosophical, not technical; and substitution re-emerged because he hoped for a new philosophical gloss on orders. Whether or not my explanations are correct, these issues must be addressed in accounting for Russell’s reasons for ramification. (shrink)

We investigate the substitution Frege () proof system and its relationship to extended Frege () in the context of modal and superintuitionistic propositional logics. We show that is p-equivalent to tree-like , and we develop a “normal form” for -proofs. We establish connections between for a logic L, and for certain bimodal expansions of L.We then turn attention to specific families of modal and si logics. We prove p-equivalence of and for all extensions of , all tabular logics, all logics (...) of finite depth and width, and typical examples of logics of finite width and infinite depth. In most cases, we actually show an equivalence with the usual system for classical logic with respect to a naturally defined translation.On the other hand, we establish exponential speed-up of over for all modal and si logics of infinite branching, extending recent lower bounds by P. Hrubeš. We develop a model-theoretical characterization of maximal logics of infinite branching to prove this result. (shrink)

The capital approach is frequently used to model sustainability. A development is deemed to be sustainable when capital is not reduced. There are different definitions of sustainability, based on whether or not they allow that different forms of capital may be substituted for each other. A development that allows for the substitution of different forms of capital is called weakly sustainable. This article shows that in a risky world and a risk-averse society even under the assumptions of weak sustainability the (...) circumstances under which different forms of capital may be substituted are limited. This is due to the risk-reducing effect of diversification. Using Modern Portfolio Theory this article shows under which conditions substitution of different forms of capital increases risk for future generations. (shrink)

This note presents a transcription of Russell's letter to Hawtrey of 22 January 1907 accompanied by some proposed emendations. In that letter Russell describes the paradox that he says "pilled" the "substitutional theory" developed just before he turned to the theory of types. A close paraphrase of the derivation of the paradox in a contemporary Lemmon-style natural deduction system shows which axioms the theory must assume to govern its characteristic notion of substituting individuals and propositions for each other in other (...) propositions. Other discussions of this paradox in the literature are mentioned. I conclude with remarks about the significance of the paradox for Russell. (shrink)

This report highlights and explores five questions that arose from the workshop on sensory substitution and augmentation at the British Academy, March 26th through 28th, 2013.

Philosophers of language traditionally take it that anti-substitution intuitions teach us about the content of belief reports. Jennifer Saul [1997, 2002 (with David Braun), 2007] challenges this lesson. Here I offer a response to Saul’s challenge. In the first two sections of the article, I present a common sense justification for drawing conclusions about content from anti-substitution intuitions. Then, in Sect. 3, I outline Saul’s challenge—what she calls ‘the Enlightenment Problem’. Finally, in Sect. 4, I argue that Saul’s challenge does (...) not undermine the common sense justification presented in Sects. 1 and 2. I avoid the challenge by arguing that anti-substitution intuitions are not directly sensitive to the content of the sentences that produce them, but rather to the possibility that one could have distinct ways of thinking about an object. (shrink)

The 'substitution argument' purports to demonstrate the falsity of Russellian accounts of belief-ascription by observing that, e.g., these two sentences: (LC) Lois believes that Clark can fly. (LS) Lois believes that Superman can fly. could have different truth-values. But what is the basis for that claim? It seems widely to be supposed, especially by Russellians, that it is simply an 'intuition', one that could then be 'explained away'. And this supposition plays an especially important role in Jennifer Saul's defense of (...) Russellianism, based upon the existence of an allegedly similar contrast between these two sentences: (PC) Superman is more popular than Clark. (PS) Superman is more popular than Superman. The latter contrast looks pragmatic. But then, Saul asks, why shouldn't we then say the same about the former? The answer to this question is that the two cases simply are not similar. In the case of (PC) and (PS), we have only the facts that these strike us differently, and that people will sometimes say things like (PC), whereas they will never say things like (PS). By contrast, there is an argument to be given that (LS) can be true even if (LC) is false, and this argument does not appeal to anyone's 'intuitions'. The main goal of the paper is to present such a version of the substitution argument, building upon the treatment of the Fregan argument against Russellian accounts of belief itself in "Solving Frege's Puzzle". A subsidiary goal is to contribute to the growing literature arguing that 'intuitions' simply do not play the sort of role in philosophical inquiry that so-called 'experimental philosophers' have supposed they do. (shrink)