It is known that an epsilon-invariant sentence has a first-order reformulation, although it is not in an explicit form, since, the proof uses the non-constructive interpolation theorem. We make an attempt to describe the explicit meaning of sentences containing epsilon-terms, adopting the strong assumption of their first-order reformulability. We will prove that, if a monadic predicate is syntactically independent from an epsilon-term and if the sentence obtained by substituting the variable of the predicate with the epsilon-term is epsilon-invariant, then the (...) sentence has an explicit first-order reformulation. Finally, we point out that the formula gives a contextual-quantificational meaning for the indefinite descriptions, provided that one accepts Kneebone’s read of epsilon-terms. (shrink)

We explore depth substitution invariance, or hyperformalism, and extend known results in this realm to justification logics extending weak relevant logics. We then examine the surprising invariance of justifications over formulas and restrict our attention to the substitution of proofs in the original relevant logic. The results of this paper indicate that depth invariance is a recalcitrant feature of the logic and that proof structures in hyperformal logics are quite inflexible.

If p(x 1 ,...,x n ) and q(x 1 ,...,x n ) are two logically equivalent propositions then p(π (x 1 ),...,π (x n )) and q(π (x 1 ),...,π (x n )) are also logically equivalent where π is an arbitrary permutation of the elementary constituents x 1 ,...,x n . In Quantum Logic the invariance of logical equivalences breaks down. It is proved that the distribution rules of classical logic are in fact equivalent to the meta-linguistic rule (...) of universal substitution and that the more restrictive structure of the substitution group of Quantum Logic prevents us from defining truth in a classical fashion. These observations lead to a more profound understanding of the Logic of Quantum Mechanics and of the role that symmetry principles play in that theory. (shrink)

The strategies of action employed by a human subject in order to perceive simple 2-D forms on the basis of tactile sensory feedback have been modelled by an explicit computer algorithm. The modelling process has been constrained and informed by the capacity of human subjects both to consciously describe their own strategies, and to apply explicit strategies; thus, the strategies effectively employed by the human subject have been influenced by the modelling process itself. On this basis, good qualitative and semi-quantitative (...) agreement has been achieved between the trajectories produced by a human subject, and the traces produced by a computer algorithm. The advantage of this reciprocal modelling option, besides facilitating agreement between the algorithm and the empirically observed trajectories, is that the theoretical model provides an explanation, and not just a description, of the active perception of the human subject. (shrink)

Enactive cognitive science (ECS) and ecological psychology (EP) agree that active movement is important for perception, but they remain ambiguous regarding the precise role of agency. EP has focused on the notion of sensorimotor invariants, according to which bodily movements play an instrumental role in perception. ECS has focused on the notion of sensorimotor contingencies, which goes beyond an instrumental role because skillfully regulated movements are claimed to play a constitutive role. We refer to these two hypotheses as instrumental agency (...) and constitutive agency, respectively. Evidence comes from a variety of fields, including neural, behavioral, and phenomenological research, but so far with confounds that prevent an experimental distinction between these hypotheses. Here we advance the debate by proposing a novel double-participant setup that aims to isolate agency as the key variable that distinguishes bodily movement in active and passive conditions of perception. We pilot this setup with a psychological study of width discrimination using the Enactive Torch, a haptic sensory substitution device. There was no evidence favoring the stronger hypothesis of constitutive agency over instrumental agency. However, we caution that during debriefing several participants reported using cognitive strategies that did not rely on spatial perception. We conclude that this approach is a viable direction for future research, but that greater care is required to establish and confirm the desired modality of first-person experience. (shrink)

In the course of his work on optics and electrodynamics in systems moving through the ether, the 19th-century medium for light waves and electric and magnetic fields, Lorentz discovered and exploited the invariance of the free-field Maxwell equations under what Poincaré later proposed to call Lorentz transformations. To account for the negative results of optical experiments aimed at detecting the earth’s motion through the ether, Lorentz, in effect, assumed that the laws governing matter interacting with light waves are Lorentz (...) invariant as well. Like Lorentz, Einstein first encountered the Lorentz transformations in electrodynamics. Unlike Lorentz, for whom the transformation merely provided convenient mathematical substitutions, but like Poincaré, Einstein recognized that the Lorentz-transformed quantities are the measured quantities for the moving observer. More importantly, Einstein recognized that the Lorentz invariance of all physical laws had nothing to do with electrodynamics per se, but reflected the kinematics in a new relativistic space-time, to be named after Minkowski who worked out its geometry a few years later. (shrink)

In the 1970's a problem arose for the viability of Popper's truthlikeness project. The problem, in short, was that all plausible measures of the truthlikeness of scientific theories were language dependent. This dissertation is primarily concerned to provide a substitute notion that can do the work 'verisimilitude' was intended to do without suffering from linguistic relativity. It is argued that the notion of 'knowledge', or 'knowledgelikeness', can suffice in this regard. ;Chapter One seeks to convince the reader that the notion (...) of 'truthlikeness' is intrinsically non-objective; all attempts to salvage the objectivity of truthlikeness have failed. Chapters Two, Three, and Four argue that the various language dependence arguments can be overcome by adopting a knowledge-based approach. Chapter Five attempts to diagnose the underlying cause behind the failure of the verisimilitude project. (shrink)

It is widely believed that some puzzling and provocative remarks that Frege makes in his late writings indicate he rejected independence arguments in geometry, particularly arguments for the independence of the parallels axiom. I show that this is mistaken: Frege distinguished two approaches to independence arguments and his puzzling remarks apply only to one of them. Not only did Frege not reject independence arguments across the board, but also he had an interesting positive proposal about the logical structure of correct (...) independence arguments, deriving from the geometrical principle of duality and the associated idea of substitution invariance. The discussion also serves as a useful focal point for independently interesting details of Frege's mathematical environment. This feeds into a currently active scholarly debate because Frege's supposed attitude to independence arguments has been taken to support a widely accepted thesis (proposed by Ricketts among others) concerning Frege's attitude toward metatheory in general. I show that this thesis gains no support from Frege's puzzling remarks about independence arguments. (shrink)

Suszko’s problem is the problem of finding the minimal number of truth values needed to semantically characterize a syntactic consequence relation. Suszko proved that every Tarskian consequence relation can be characterized using only two truth values. Malinowski showed that this number can equal three if some of Tarski’s structural constraints are relaxed. By so doing, Malinowski introduced a case of so-called mixed consequence, allowing the notion of a designated value to vary between the premises and the conclusions of an argument. (...) In this article we give a more systematic perspective on Suszko’s problem and on mixed consequence. First, we prove general representation theorems relating structural properties of a consequence relation to their semantic interpretation, uncovering the semantic counterpart of substitution-invariance, and establishing that mixed consequence is fundamentally the semantic counterpart of the structural property of monotonicity. We use those theorems to derive maximum-rank results proved recently in a different setting by French and Ripley, as well as by Blasio, Marcos, and Wansing, for logics with various structural properties. We strengthen these results into exact rank results for nonpermeable logics. We discuss the underlying notion of rank, and the associated reduction proposed independently by Scott and Suszko. As emphasized by Suszko, that reduction fails to preserve compositionality in general, meaning that the resulting semantics is no longer truth-functional. We propose a modification of that notion of reduction, allowing us to prove that over compact logics with what we call regular connectives, rank results are maintained even if we request the preservation of truth-functionality and additional semantic properties. (shrink)

Every Berman’s variety \ which is the subvariety of Ockham algebras defined by the equation \ and \) determines a finitary substitution invariant consequence relation \. A sequent system \ is introduced as an axiomatization of the consequence relation \. The system \ is characterized by a single finite frame \ under the frame semantics given for the formal language. By the duality between frames and algebras, \ can be viewed as a \-valued logic as it is characterized by (...) a distributive lattice of \ elements with a unary operator. Moreover, a structural-rule-free, cut-free and terminating sequent system \ is established for \. The Craig interpolation property of \ is shown proof-theoretically utilizing \. (shrink)

Most Gentzen systems arising in logic contain few axiom schemata and many rule schemata. Hilbert systems, on the other hand, usually contain few proper inference rules and possibly many axioms. Because of this, the two notions tend to serve different purposes. It is common for a logic to be specified in the first instance by means of a Gentzen calculus, whereupon a Hilbert-style presentation ‘for’ the logic may be sought—or vice versa. Where this has occurred, the word ‘for’ has taken (...) on several different meanings, partly because the Gentzen separator ⇒ can be interpreted intuitively in a number of ways. Here ⇒ will be denoted less evocatively by ⊲.In this paper we aim to discuss some of the useful ways in which Gentzen and Hilbert systems may correspond to each other. Actually, we shall be concerned with thededucibility relationsof the formal systems, as it is these that are susceptible to transformation in useful ways. To avoid potential confusion, we shall speak of Hilbert and Gentzenrelations. By aHilbert relationwe mean any substitution-invariant consequence relation onformulas—this comes to the same thing as the deducibility relation of a set of Hilbert-style axioms and rules. By aGentzen relationwe mean the fully fledged generalization of this notion in whichsequentstake the place of single formulas. In the literature, Hilbert relations are often referred to assentential logics. Gentzen relations as defined here are their exactsequentialcounterparts. (shrink)

Graham Priest has asked whether the consequence relation associated with the Anderson–Belnap system of Tautological Entailment,1 in the language with connectives ¬, ∧, ∨, and countably many propositional variables as tomic formulas, maximal amongst the substitution-invariant relevant consequence relations on this language. Here a consequence relation is said to be relevant just in case whenever for a set of formulas Γ and formula B, we have Γ B only if some propositional variable occurring in B occurs in at least (...) one formula in Γ. (It follows that relevant consequence relations are atheorematic in the sense that whenever Γ B for some such consequence relation , Γ = ∅.) Here I write up in more detail the upshot of the conversation – returning an affirmative answer to Priest’s question – about this in the common room that Greg Restall and I were participating in last Friday [ = October 6, 2006], dotting some “i”s and crossing some “t”s (and adding the odd further reflection). (shrink)

The use of models to assign truth values to sentences and to counterexemplify invalid inferences is a basic feature of model theory. Yet sentences and inferences are not the only phenomena that model theory has to take care of. In particular, the development of sequent calculi raises the question of how metainferences are to be accounted for from a model-theoretic perspective. Unfortunately there is no agreement on this matter. Rather, one can find in the literature two competing model-theoretic notions of (...) metainferential validity, known as the ‘global’ notion and the ‘local’ notion. In this article, I argue that, given certain plausible considerations about metainferential validity, the global notion collapses into the local notion. (shrink)

Kim’s Ontological Physicalism (OP) presents itself as a naturalistic and monistic metaphysical framework, aligned with the causal closure of the universe and rejecting causally efficacious “exotic” properties. The foundational ontology is, in turn, monistic and materialistic, positing that the universe is composed solely of material particulars: bits of matter. In this work, we identify a notable tension between OP’s intended model and the one OP specifies. Initially, we show how the theory inevitably becomes entangled with higher-order entities, not just particulars. (...) Kim introduces the Supervenience Argument (SA) to counteract the possibility of higher-order entities being causally efficacious. While SA proves to be a plausible strategy, it is ultimately inadequate: not only SA is a petitio principii against emergence, but it is also unsound and invalid. Therefore, we propose a formal strategy to restore its ontological effectiveness. Unfortunately, at a closer look, even this strategy falls short as it unwarrantedly assumes the logicality and invariance of those equivalence relations (such as identity, similarity, and congruence) which are crucial for specifying the theory’s model as composed of particulars. (shrink)

Tarski and Mautner proposed to characterize the "logical" operations on a given domain as those invariant under arbitrary permutations. These operations are the ones that can be obtained as combinations of the operations on the following list: identity; substitution of variables; negation; finite or infinite disjunction; and existential quantification with respect to a finite or infinite block of variables. Inasmuch as every operation on this list is intuitively "logical", this lends support to the Tarski-Mautner proposal.

Nominalism in formal ontology is still the thesis that the only acceptable domain of quantification is the first-order domain of particulars. Nominalists may assert that second-order well-formed formulas can be fully and completely interpreted within the first-order domain, thereby avoiding any ontological commitment to second-order entities, by means of an appropriate semantics called “substitutional”. In this paper I argue that the success of this strategy depends on the ability of Nominalists to maintain that identity, and equivalence relations more in general, (...) is first-order and invariant. Firstly, I explain why Nominalists are formally bound to this first-order concept of identity. Secondly, I show that the resources needed to justify identity, a certain conception of identity invariance, are out of the Nominalist’s reach. (shrink)

Particularism denies that invariant valence is always possible and that it is needed in sound moral theorising. It relies on variabilism, namely the idea that the relevant features of a given situation can alter their moral valence even across seemingly similar cases. An alternative model is defended (the “disappearing model”), in which changes in the overall relevance of complex cases are explained by re-individuation of the constituent features: certain features do not alter their relevance in consequence of contextual changes, but (...) rather they disappear, either because they are embedded within larger complexes or are substituted by different features. This view is shown to be compatible with the main premises of variabilism and explanatorily superior to it. Nevertheless, it does not involve particularism, but rather a peculiar form of generalism. (shrink)

In this paper, I advance a new view of the semantics of indexicals, using a paper by Quentin Smith as my starting point. I make use of Smith’s examples, refined and expanded upon by myself to argue, as Smith does, that the standard view, that indexicals refer to some prominent features of the context according to an invariant rule called the character, does not agree with a wide range of phenomena. I depart from Smith, however, in denying that we need (...) more complex rules, which he does not give, called metacharacters to account for all the deviations, and instead argue for a view of indexicals as just being special cases of demonstratives. I show how demonstratives can be substituted for indexicals to support this view, and I adduce recent work in the semantics of demonstratives to explain how it can work. (shrink)

Special relativity has changed the fundamental view on space and time since Einstein introduced it in 1905. It substitutes four dimensional spacetime for the absolute space and time of Newtonian mechanics. It is believed that the validities of Lorentz invariants are fully confirmed empirically for the last one hundred years and therefore its status are canonical underlying all physical principles. However, spacetime metric is a geometric approach on nature when we interpret the natural phenomenon. A geometric flaw on this will (...) be exhibited and the alternative is suggested. The reasonable geometric model of space and time is a three dimensional space which is translating along the time direction. This model legitimately represents the true characteristic of nature. (shrink)

Consider any choice that affects some social policy. A decision that considers evidence will, at its heart, contain some kind of explicit or implicit “because” statement: “We are doing X because the evidence says Y.” But can evidence ever truly speak for itself, in the sense of being reducible to objective utterances that are either correct or in need of correction? Before answering, consider what you'd prefer. Would you rather receive evidence that was free of any value judgments imposed by (...) human actors, that was laden with value judgments that you agree with, or laden with value judgments that you disagree with? The central assertion of this essay is that, throughout policy analysis but especially in assessments of the costs and benefits of regulating versus encouraging new technologies (cost‐benefit analysis, or CBA), the first possibility above is a mirage, and the second and third are self‐contradictory. Instead, we are overwhelmingly confronted with a fourth possibility: we receive evidence that appears to be (or is deliberately touted as) value neutral but is suffused with hidden value judgments.In the second part of this essay, entitled “A Guided Tour through Inevitable Value Judgments,” I identify in a systematic way approximately sixty‐five value judgments that are routinely (in some cases, invariably) made in CBA, but that are kept hidden. For each judgment, I discuss its genesis as it is most commonly invoked in CBA, explain how it is hidden in plain sight, and offer one or more value judgments that could be made instead of or in addition to the conventional one. The alternative judgments highlight the width of the spectrum of reasonable conclusions an analyst could reach merely by substituting other judgments for the ones currently embedded.Bringing hidden value judgments to light is doubly valuable. First, it allows discussion to ensue on a level playing field; instead of conclusory statements about what the evidence says, transparency permits statements taking the form of “when channeled through these value judgments, the evidence says this.” Perhaps more importantly, transparency about value judgments permits participants in the discussions to offer interpretations of evidence contingent on there being different value judgments chosen at one or more points in the analysis, interpretations that may suggest that alternative course(s) of action are preferable to the one being championed. (shrink)

We use the notion of polar duality from convex geometry and the theory of Lagrangian planes from symplectic geometry to construct a fiber bundle over ellipsoids that can be viewed as a quantum-mechanical substitute for the classical symplectic phase space. The total space of this fiber bundle consists of geometric quantum states, products of convex bodies carried by Lagrangian planes by their polar duals with respect to a second transversal Lagrangian plane. Using the theory of the John ellipsoid we relate (...) these geometric quantum states to the notion of “quantum blobs” introduced in previous work; quantum blobs are the smallest symplectic invariant regions of the phase space compatible with the uncertainty principle. We show that the set of equivalence classes of unitarily related geometric quantum states is in a one-to-one correspondence with the set of all Gaussian wavepackets. We emphasize that the uncertainty principle appears in this paper as geometric property of the states we define, and is not expressed in terms of variances and covariances, the use of which was criticized by Hilgevoord and Uffink. (shrink)

The long standing reign of psychology as the privileged partner of education has, arguably, now been superseded by the neurosciences. Given that this helped to drive the emergent field of neuroeducation, it is crucial to ask what changes in education, if anything does in fact change, when the hitherto hegemonic psychologising discourse is substituted for a neurological one. The primary contention of this paper is that with the neuro-turn a process of “neurologisation” has also been initiated, which can be analysed (...) by taking into account its genealogical predecessor, psychologisation. In doing so, I argue, one ultimately discerns a primordial incompatibility between education and neuroscience, one that can be traced back to the fundamental and problematic reflexivity of modern subjectivity itself, which the discipline of psychology was never able to wholly resolve. From here, I proceed with the argument that while the eagerness of the psy-sciences to embrace neuroscience testifies to how much psychology needs neurology, the neurosciences are structurally incapable of disconnecting from the paradigms of the psy-sciences. Following on from this proposition, other strong/weak factors are brought into the equation: strong/weak nature, strong/weak culture, strong/weak subjectivity and, most pertinently, strong/weak education. Finally, the critical question becomes: if education in itself needs to take recourse to both the psy-sciences and the neurosciences, then how can we begin to account for the fact that these sciences invariably end up becoming captured within educational discourses themselves; that is, the fact that teachers, parents, and pupils themselves are taught the key insights of neuropsychology. (shrink)

The Wigner–Weyl mapping of quantum operators to classical phase space functions preserves the algebra, when operator multiplication is mapped to the binary “*” operation. However, this isomorphism is destroyed under the quasiclassical substitution of * with conventional multiplication; consequently, an approximate mapping is required if algebraic relations are to be preserved. Such a mapping is uniquely determined by the fundamental relations of quantum mechanics, as is shown in this paper. The resultant quasiclassical approximation leads to an algebraic derivation of (...) Thomas–Fermi theory, and a new quantization rule which—unlike semiclassical quantization—is non-invariant under action transformations of the Hamiltonian, in the same qualitative manner as the true eigenvalues. The quasiclassical eigenvalues are shown to be significantly more accurate than the corresponding semiclassical values, for a variety of 1D and 2D systems. In addition, certain standard refinements of semiclassical theory are shown to be easily incorporated into the quasiclassical formalism. (shrink)

Established scholarship in arts education is invariably related to theories of development founded on notions of multiple intelligence and experiential learning. Yet when contemporary arts practice is retraced on a philosophical horizon, one begins to engage with other cases for learning. This state of affairs reveals art’s inherent paradox where the expectation of learning is substituted by forms of unlearning. This paper begins to approach unlearning through the tension between art and education, and more specifically through the dialectical relationship between (...) education’s dialogic agonism and art’s negative antagonism. What is here being proposed as unlearning reflects a critique of the moral-pedagogical outlooks that are imposed on art where artworks are expected to tell stories of truth through their propensity towards the beautiful and the good. In re-reading experiential anticipation as a form of anamnesis through a process of negation and contradiction, unlearning is also located in forms of mimetic scoping by which art’s assumed pedagogical trajectory turns into the opposite of recollection: as an act of willed forgetfulness. This peculiar ‘movement’ from a state of learning to that of unlearning constitutes the basis for a special kind of pedagogical aesthetics where the challenges of criticality and laterality articulate a special ‘world’ where learning may well work backwards. (shrink)

'Stress' is a widely used word in clinical practice, the biological sciences and everyday life; but one which has little real value, serving mainly to confuse and confound rational thought. Whether it is described in terms of stimulus, response, or a combination of the two the definitions of stress are invariably found to be circular. We should stop using the word 'stress' and instead discuss specific stimuli or responses as appropriate. The author suggests that 'pressure' and 'tension' might provide suitable (...) substitutes for everyday clinical practice. (shrink)

(1) The idea that diffraction of matter particles can only be understood in terms of a temporary wave transformation or 'double manifestation' is an uneconomical ad hoc hypothesis, shattered already in 1923 by the unitary quantum theory of diffraction of Duane which in 1926 became part of the quantum mechanics, with a statistical interpretation of wave-like appearances. (2) Bohr's re-interpretation of Heisenberg's uncertainty of prediction as an indeterminacy of existence rests on an illegitimate literal translation of a wave result into (...) particle language which is at variance with experience as well as with the statistical interpretation. (3) The fact that one can transform the simple and unitary particle mechanics into a complicated wavelike form is only a weak substitute for genuine dualism -- as if one would see dualism in the transformability from the geo- to the heliocentric reference system. (4) The strongest argument against a symmetry of the particle and the wave theory of matter is the explainability of the former in terms of simple postulates of invariance, leaving the wave formalism as a purely ad hoc construction. (shrink)

The classical notion of scientific objectivity is a property of propositional truth. It is the property of being open to testing and inspection, in principle, by all men, although in practice perhaps, the testing of a scientific claim is restricted to the members of a community of professional experts. It is, moreover, the property of being stable in time, true eternally as it were; for objective truth is thought to express what is so independently of human interests, initiatives, bias, social (...) circumstances and historical environment. Often there is the added connotation that what is so is pictured not in its relationship to man, but absolutely, as it were, in itself, or in its relations to the rest of nature, where nature is taken to have an essence independently of the meaning conferred on nature by Dasein. All this is expressed as truth-invariance relative to synchronous communities of knowers whether sympatric or allopatric : truth-invariance relative to allochronous communities of knowers, and truth-invariance relative to the physical transformations and substitutions which define the objective content of a scientific law or theory. (shrink)

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)

It is tempting to think that a process of choosing a point at random from the surface of a sphere can be probabilistically symmetric, in the sense that any two regions of the sphere which differ by a rotation are equally likely to include the chosen point. Isaacs, Hájek, and Hawthorne (2022) argue from such symmetry principles and the mathematical paradoxes of measure to the existence of imprecise chances and the rationality of imprecise credences. Williamson (2007) has argued from a (...) related symmetry principle to the failure of probabilistic regularity. We contend that these arguments fail, because they rely on auxiliary assumptions about probability which are inconsistent with symmetry to begin with. We argue, moreover, that symmetry should be rejected in light of this inconsistency, and because it has implausible decision- theoretic implications. -/- The weaker principle of probabilistic invariance says that the probabilistic comparison of any two regions is unchanged by rotations of the sphere. This principle supports a more compelling argument for imprecise probability. We show, however, that invariance is incompatible with mundane judgments about what is probable. Ultimately, we find reason to be suspicious of the application of principles like symmetry and invariance to nonmeasurable regions. (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)

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)

Substituted judgement is often used in the absence of advanced directives to guide decision-making when patients lack decisional capacity. We present a remarkable case of family members exercising substituted misjudgement for a 42-year-old man hospitalized with multiorgan failure on life support. Feeling that their loved one would rather die than face severe disability, they elected to withdraw life support. Although this was done, the patient remained alive and recovered enough to clearly indicate his preference for life, even with severe disability. (...) This case suggests that in instances of unusual quality-of-life judgements where the patient's wishes cannot be known with reasonable certainty, families and physicians should be very wary using substituted judgement to refuse life support. Unless there are strong considerations based on the patient's prior statements, actions and values to decline life support, it would seem ethically appropriate to continue treatment, even with substantial disability the likely outcome. (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)

Many philosophers are baffled by necessity. Humeans, in particular, are deeply disturbed by the idea of necessary laws of nature. In this paper I offer a systematic yet down to earth explanation of necessity and laws in terms of invariance. The type of invariance I employ for this purpose generalizes an invariance used in meta-logic. The main idea is that properties and relations in general have certain degrees of invariance, and some properties/relations have a stronger degree (...) of invariance than others. The degrees of invariance of highly-invariant properties are associated with high degrees of necessity of laws governing/describing these properties, and this explains the necessity of such laws both in logic and in science. This non-mysterious explanation has rich ramifications for both fields, including the formality of logic and mathematics, the apparent conflict between the contingency of science and the necessity of its laws, the difference between logical-mathematical, physical, and biological laws/principles, the abstract character of laws, the applicability of logic and mathematics to science, scientific realism, and logical-mathematical realism. (shrink)

In this note we outline the history of q-deformations, indicate their physical shortcomings, suggest their apparent resolution via an invariant Lie-admissible formulation based on a new mathematics of genotopic type, and point out their expected physical significance.

Eino Kaila's thought occupies a curious position within the logical empiricist movement. Along with Hans Reichenbach, Herbert Feigl, and the early Moritz Schlick, Kaila advocates a realist approach towards science and the project of a “scientific world conception”. This realist approach was chiefly directed at both Kantianism and Poincaréan conventionalism. The case in point was the theory of measurement. According to Kaila, the foundations of physical reality are characterized by the existence of invariant systems of relations, which he called structures. (...) In a certain sense, these invariant structures, he maintained, are constituted in the act of measuring. By “constitution”, however, Kaila meant neither the dependency of the objects of measurement on a priori concepts (or Kantian categories) nor their being effected by conventional stipulations in a Poincaréan sense. He held that invariant structures are, quite literally, real: they exist prior to and independently of our theoretical capacity. By executing measurements, invariant structures are detected and objectively determinable by laws of nature. (shrink)

Although the invariance criterion of logicality first emerged as a criterion of a purely mathematical interest, it has developed into a criterion of considerable linguistic and philosophical interest. In this paper I compare two different perspectives on this criterion. The first is the perspective of natural language. Here, the invariance criterion is measured by its success in capturing our linguistic intuitions about logicality and explaining our logical behavior in natural-linguistic settings. The second perspective is more theoretical. Here, the (...) invariance criterion is used as a tool for developing a theoretical foundation of logic, focused on a critical examination, explanation, and justification of its veridicality and modal force. (shrink)

The presence of symmetries in physical theories implies a pernicious form of underdetermination. In order to avoid this theoretical vice, philosophers often espouse a principle called Leibniz Equivalence, which states that symmetry-related models represent the same state of affairs. Moreover, philosophers have claimed that the existence of non-trivial symmetries motivates us to accept the Invariance Principle, which states that quantities that vary under a theory’s symmetries aren’t physically real. Leibniz Equivalence and the Invariance Principle are often seen as (...) part of the same package. I argue that this is a mistake: Leibniz Equivalence and the Invariance Principle are orthogonal to each other. This means that it is possible to hold that symmetry-related models represent the same state of affairs whilst having a realist attitude towards variant quantities. Various arguments have been presented in favour of the Invariance Principle: a rejection of the Invariance Principle is inter alia supposed to cause indeterminism, undetectability or failure of reference. I respond that these arguments at best support Leibniz Equivalence. (shrink)

Necessary and sufficient conditions ofinvariance on four-vectors under the Poincaré group E(3, 1) and its subgroups are exploited. As an example the Euclidean group in three dimensions and its subgroups are explicitly considered. Their invariant “potentials” are systematically derived.

In the context of a parametric theory (with the time being a dynamical variable) we consider here the coupling between the quantum vacuum and the background gravitation that pervades the universe (unavoidable because of the universality and long range of gravity). We show that this coupling, combined with the fourth Heisenberg relation, would break the parametric invariance of the gravitational equations, introducing thus a difference between the marches of the atomic and the astronomical clocks. More precisely, they would be (...) progressively and adiabatically desynchronized with respect to one another in such a way that the latter would lag behind the former. This would produce a discrepancy between gravitational theory and observations, which use astronomical and atomic time respectively. It turns out that this result, surprising at it might be, is fully compatible with current physics, since it does not conflict with any known physical law or principle. We argue that this phenomenon must be studied, since it could have cosmological consequences. (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 (...) class='Hi'>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)

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)

Excerpts from Robert Nozick's "Invariances" Necessary truths are invariant across all possible worlds, contingent ones across only some.

This paper explores the relation between natural modality and our modelling practices. It will be argued that some modelling practices such as abstraction and idealization should be understood as presupposing empirical claims about objective modal features of the behavior of target systems. To establish the connection between natural modality on the one hand and modelling practices on the other an analysis of natural modality in terms of empirically accessible invariance relations will be provided.