Online research in philosophy

What remains when you eliminate all matter? Can empty space-a void-exist? _Frank Close takes the reader on a lively and accessible tour through ancient ideas and cultural superstitions (including Aristotle, who insisted that the vacuum was impossible) to the frontiers of current scientific research. These newest discoveries tell us extraordinary things about the cosmos and may provide answers to some of our most fundamental questions: What lies outside the universe? If there was once nothing, then how did the universe (...) begin? (shrink)

This short, smart book tells you everything you need to know about "nothing." What remains when you take all the matter away? Can empty space--"nothing"--exist?

G.W.F. Hegel's aesthetics, or philosophy of art, forms part of the extraordinarily rich German aesthetic tradition that stretches from J.J. Winckelmann's Thoughts on the Imitation of the Painting and Sculpture of the Greeks (1755) and G.E. Lessing's Laocoon (1766) through Immanuel Kant's Critique of the Power of Judgment (1790) and Friedrich Schiller's Letters on the Aesthetic Education of Man (1795) to Friedrich Nietzsche's Birth of Tragedy (1872) and (in the twentieth century) Martin Heidegger's The Origin of the Work of Art (...) (1935–6) and T.W. Adorno's Aesthetic Theory (1970). Hegel was influenced in particular by Winckelmann, Kant and Schiller, and his own thesis of the “end of art” (or what has been taken to be that thesis) has itself been the focus of close attention by Heidegger and Adorno. Hegel's philosophy of art is a wide ranging account of beauty in art, the historical development of art, and the individual arts of architecture, sculpture, painting, music and poetry. It contains distinctive and influential analyses of Egyptian art, Greek sculpture, and ancient and modern tragedy, and is regarded by many as one of the greatest aesthetic theories to have been produced since Aristotle's Poetics. (shrink)

This bibliographical review of the modelling of the mitotic apparatus covers a period of one hundred and twenty years, from the discovery of the bipolar mitotic spindle up to the present day. Without attempting to be fully comprehensive, it will describe the evolution of the main ideas that have left their mark on a century of experimental and theoretical research. Fol and Bütschli's first writings date back to 1873, at a time when Schleiden and Schwann's cell theory was rapidly gaining (...) ground throughout Germany. Both mitosis and chromosomes were to be discovered within the space of thirty years, along with the two key events in the animal and plant reproductive cycle, namely fecondation and meiosis. The mitotic pole, a term still in use to this day, was employed to describe a morphological fact which was noted as early as 1876, namely that the lines and the dots of the karyokinetic figure, with its spindle and asters, looks remarkably like the lines of force around a bar magnet. This was to lead to models designed to explain the movements of chromosomes which take place when the cell nucleus appears to cease to exist as an organelle during mitosis. The nature of those mechanisms and the origin of the forces behind the chromosomes' ordered movements were central to the debate. Auguste Prenant, in a remarkable bibliographical synthesis published in 1910, summed up the opposing viewpoints of the vitalists, on the one hand, who favoured the theory of contractility or extensility in spindle fibres, and of those who believed in models based on physical phenomena, on the other. The latter subdivided into two groups: some, like Bütschli, Rhumbler or Leduc, referred to diffusion, osmosis and superficial tension, whilst the others, led by Gallardo and Hartog, focussed on the laws of electromagnetism. Lillie, Kuwada and Darlington followed up this line of research. The mid-20th century was a major turning point. Most of the modelling mentioned above was criticized and fell into disuse after disappearing from research publications and textbooks.This marked the onset of a new era, as electron microscopes made possible the materialization and detailed study of the macromolecular elements of the fibres, filaments and microtubules of the cytoskeleton. The successive phases of (a) de Harven and Bernhard's 1956 discovery of the centriole's ultrastructure, (b) its identification with the basal body of the cilia and flagella, confirming the theory set out by Henneguy and von Lenhossek (1898–99), (c) the universal presence of microtubules in animal, vegetal and eukaryotic protist cells, (d) the polymerization-depolymerization induced reversible transformations of the tubulin pool in mitosing cells (Inoue, 1960), (e) ultrastructural comparative studies of the mitotic apparatus of eukaryotes illustrating the Pickett-Heaps integrating concept of the MTOC (microtubule-organizing centre), (f) the possibility ofin vitro experiments on mtocs or on microtubules, brings us upon the present day, which has seen the focus placed on the concept of motor-proteins (kinesin, dynein) and on cell cycle models. The latter are based on a close coincidence between the observable modifications of the mitotic apparatus and the periodic variations in intracellular concentrations of calcium or of certain enzymes (cyclins, Cdc2) during the main transitions of the cell cycle. (shrink)

August 16, 1997 David Lewis2 has long defended an account of scientific law acceptable even to an empiricist with significant metaphysical scruples. On this account, the laws are defined to be the consequences of the best system for axiomitizing all occurrent fact. Here "best system" means the set of sentences which yields the best combination of strength of descriptive content 3 with simplicity of exposition. And occurrent facts, the facts to be systematized, are roughly the particular facts about a localized (...) space-time region that are non-modal, non-dispositional, and non-causal. Scientists providing or attempting to provide laws are plausibly seen as giving general principles that unify a body of data. Thus they organize or systematize the arrangement of occurrences. For this reason, Lewis's account has the important merits of providing contact with actual scientific practice while making sense of the standard philosophical conception that laws should be general but more than mere accidental generalizations. However, Lewis has long known about a potential problem with this account, a problem involving chance and credence.4 In a recent series of articles he, Michael Thau, and Ned Hall have developed a new formulation of the relationship between chance and credence which solves the problem. However, I will argue that these articles leave untouched and even exacerbate a closely related and more fundamental problem with the best system account, the problem of nomic necessity. Laws are supposed to be more than true; in some sense they must be true. Yet a principle's membership in the best systematization for one world seems to say nothing about its necessity, i.e., its truth at other worlds. I close by briefly describing how an alternative empiricist account may remove both problems. (shrink)

Hume's is/ought distinction has long limited the role of empirical research in ethics, saying that data about what something is cannot yield conclusions about the way things ought to be. However, interest in empirical research in ethics has been growing despite this countervailing principle. We attribute some of this increased interest to a conceptual breakdown of the is/ought distinction. MacIntyre, in reviewing the history of the is/ought distinction, argues that is and ought are not strictly separate realms but exist in (...) a close relationship that is clarified by adopting a teleological orientation. We propose that, instead of recovering a teleological orientation, society tends to generate its own goals via democratic methods like those described by Rousseau or adopt agnosticism about teleology such as described by Richard Rorty. In both latter scenarios, the distinction between is and ought is obscured, and the role for empirical research grows, but for controversial reasons. MacIntyre warns that the is/ought distinction should remain, but reminds ethicists to make careful arguments about when and why it is legitimate to move from is to ought. (shrink)

We give a complete description of minimal groups infinitely definable in separably closed fields of finite degree of imperfection. In particular we answer positively the question of the existence of such a group with infinite transcendence degree (i.e., a minimal group with non thin generic).

Call a family F of subsets of a set E inductive if ∅ ∈ F and F is closed under unions with disjoint singletons, that is, if ∀X∈F ∀x∈E–X(X ∪ {x} ∈ F]. A Frege structure is a pair (E.

Demonstrative noun phrases (e.g. this; that guy over there ) are intimately connected to the context of use in that their reference is determined by demonstrations and/or the speaker's intentions. The semantics of demonstratives therefore has important implications not only for theories of reference, but for questions about how information from the context interacts with formal semantics. First treated by Kaplan as directly referential , demonstratives have recently been analyzed as quantifiers by King, and the choice between these two approaches (...) is a matter of ongoing controversy. Meanwhile, linguists and psychologists working from a variety of perspectives have gathered a wealth of data on the form, meaning, and use of demonstratives in many languages. Demonstratives thus provide a fruitful topic for graduate study for two reasons. On the one hand, they serve as an entry point to foundational issues in reference and the semantics–pragmatics interface. On the other hand, they are an especially promising starting point for interdisciplinary research, which brings the results of linguistics and related fields to bear on the philosophy of language. Author Recommends Kaplan, David. 'Demonstratives.' 1977. Themes from Kaplan . Ed. J. Almong, J. Perry, and H. Wettstein. Oxford: Oxford UP, 1989. 481–563. The seminal work on the semantics of demonstratives and indexicals, such as I, here , and now . Kaplan introduces a distinction between content (which maps from possible circumstances to extensions) and character (which maps from possible contexts to contents). He argues that demonstratives and indexicals are directly referential : given a possible context, their character fixes their extension. Kaplan, David. 'Afterthoughts.' Themes from Kaplan . Ed. J. Almong, J. Perry, and H. Wettstein. Oxford: Oxford UP, 1989. 565–614. An elaboration on the theory developed in 'Demonstratives.' Kaplan considers the connection between direct reference and rigid designation; raises the issue of whether demonstratives depend on demonstrations or speaker intentions; and discusses implications of the analysis for formal semantics and for epistemology. King, Jeffrey C. Complex Demonstratives . Cambridge, MA: MIT Press, 2001. In perhaps the most influential challenge to date to the direct reference theory of demonstratives, King argues that complex demonstratives (i.e. demonstrative determiners with nominal complements) are best analyzed as quantifiers. Braun, David. 'Complex Demonstratives and Their Singular Contents.' Linguistics and Philosophy 31 (2008): 57–99. This recent Kaplanian analysis of complex demonstratives shows the 'state of the art' of direct reference approaches and responds to some of the objections to such approaches raised by King. Elbourne, Paul. 'Demonstratives as Individual Concepts.' Linguistics and Philosophy 31 (2008): 409–466. The most recent analysis of demonstratives as individual concepts, contrasting with both the direct reference and quantificational approaches. Fillmore, Charles. Lectures on Deixis . Stanford, CA: CSLI, 1997. In this collection of lectures, originally delivered in 1971, Fillmore considers demonstratives and indexical expressions in many languages to describe the types of information about the context (e.g. locations in space, time, and discourse) that are encoded in natural language. Gundel, Jeanette K., Nancy Hedberg, and Ron Zacharski. 'Cognitive Status and the Form of Referring Expressions in Discourse.' Language 69 (1993): 274–307. Perhaps the most detailed pragmatic alternative to formal semantic theories of demonstratives and other referring expressions. The authors argue that demonstratives are best described as imposing a condition of use in which the referent of the demonstrative has a certain level of salience for the interlocutors. Online Materials http://plato.stanford.edu/entries/indexicals/ Indexicals (David Braun) http://plato.stanford.edu/entries/reference/ Reference (Marga Reimer) http://plato.stanford.edu/entries/rigid-designators/ Rigid designators (Joseph LaPorte) http://philpapers.org/browse/indexicals-and-demonstratives/ Online bibliography of papers on indexicals and demonstratives Sample Syllabus The following syllabus can be used in entirety for a survey course on demonstratives; in addition, each of the three units is self-contained and can be used alone. Unit 1: Demonstratives and Indexicality Week 1: Indexicals 1. Kaplan, Demonstratives 2. Kaplan, Afterthoughts Week 2: Issues for Indexical Reference 1. Reimer, Marga. 'Do Demonstrations Have Semantic Significance?' Analysis 51 (1991): 177–83. 2. Bach, Kent. 'Intentions and Demonstrations.' Analysis 52 (1992): 140–46. 3. Nunberg, Geoffrey. 'Indexicality and Deixis.' Linguistics and Philosophy 16.1 (1993): 1–43. Week 3: Optional detour: Monsters 1. Schlenker, Philippe. 'A Plea for Monsters.' Linguistics and Philosophy 26 (2003): 29-120. Week 4: Demonstratives as Quantifiers 1. King. Complex Demonstratives , chapters 1–3. Week 5: Indexical and Non-Indexical Demonstratives 1. Braun, David. 'Complex Demonstratives and Their Singular Contents.' Linguistics and Philosophy 31 (2008): 57–99. Optional additional reading 2. Roberts, Craige. 'Demonstratives as Definites.' Information Sharing . Ed. Kees van Deemter and Roger Kibble. Stanford, CA: CSLI Press, 2002. 3. Wolter, Lynsey. 'That's That: The Semantics and Pragmatics of Demonstrative Noun Phrases.' Diss. University of California, Santa Cruz, 2006, chapters 2–3. 4. Elbourne, Paul. 'Demonstratives as Individual Concepts.' Linguistics and Philosophy 31 (2008): 409–66. Unit 2: Demonstratives, Proximity, Salience Week 6: Demonstratives and Proximity 1. Fillmore, Charles. 'Deixis I.' in Lectures on Deixis . Stanford, CA: CSLI, 1997. 59–76. 2. Fillmore, Charles. 'Deixis II.' in Lectures on Deixis . Stanford, CA: CSLI, 1997. 103–26. Optional additional reading 3. Prince, Ellen. 'On the Inferencing of Indefinite- this NPs.' Elements of Discourse Understanding . Ed. Aravind K. Joshi, Bonnie L. Weber, and Ivan A. Sag. Cambridge: Cambridge University Press, 1981. 231–50. Week 7: Demonstratives and Salience 1. Gundel, Jeanette K., Nancy Hedberg, and Ron Zacharski. 'Cognitive Status and the Form of Referring Expressions in Discourse.' Language 69 (1993): 274–307. Optional additional reading 2. Brown-Schmidt, Sarah, Donna K. Byron, and Michael K. Tanenhaus. 'Beyond Salience: Interpretation of Personal and Demonstrative Pronouns.' Journal of Memory and Language 53 (2005): 292–313. Note: readers new to psycholinguistics should concentrate on the Introduction. Unit 3: Demonstratives and Copular Sentences Week 8: Background on the Typology of Copular Sentences 1. Higgins, F. Roger. 'The Pseudo-Cleft Construction in English.' Diss. MIT, 1973, chapter 5. Week 9: Demonstratives in Copular Sentences 1. Mikkelsen, Line. 'Specifying Who: On the Structure, Meaning, and Use of Specificational Copular Clauses.' Diss. University of California, Santa Cruz, 2004, chapter 8.2 (Truncated Clefts). 2. Heller, Daphna and Lynsey Wolter. ' That is Rosa : Identificational Sentences as Intensional Predication.' Proceedings of Sinn und Bedeutung 12 . Ed. Atle Grønn. Oslo: Department of Literature, Area Studies and European Languages, University of Oslo, 2008. Week 10: Demonstratives, Copular Sentences, Modals 1. Birner, Betty J., Jeffrey P. Kaplan, and Gregory Ward. 'Functional Compositionality and the Interaction of Discourse Constraints.' Language 83 (2007): 317–43. Focus Questions 1. Which of the following expressions are indexicals? Which are demonstratives? Why? (a) a pencil (b) the pencil (c) this pencil (d) Mary Smith (e) Mary's pencil (f ) my pencil (g) we (h) you (i) here (j) there (k) now (l) then 2. Do demonstratives ever interact with scope-taking operators to give rise to two or more truth-conditionally distinct readings? If so, under what circumstances? 3. (a) If demonstratives (sometimes or always) interact with scope-taking operators to give rise to two or more truth-conditionally distinct readings, to what extent can a direct reference theory of demonstratives be maintained? (b) If demonstratives never interact with scope-taking operators to give rise to two or more truth-conditionally distinct readings, to what extent can a quantificational theory of demonstratives be maintained? 4. What kind of thing is a demonstration? Is it a pointing gesture? An indication of the speaker's focus of attention? Something more abstract? 5. What information do English demonstratives convey about proximity? What is 'proximity'– physical closeness to the speaker, or something more abstract? What is the status of this information: is it entailed, presupposed, or something else? 6. Do demonstratives that are accompanied by a physical gesture of demonstration have the same semantic value as anaphoric demonstratives, such as that in (a)? Why or why not? (a) John made a peanut butter sandwich and ate it quickly. Next he took an apple from the fridge. He ate that more slowly. (shrink)

C I Lewis showed up Down Under in 2005, in e-mails initiated by Allen Hazen of Melbourne. Their topic was the system Hazen called FL (a Funny Logic), axiomatized in passing in Lewis 1921. I show that FL is the system MEN of material equivalence with negation. But negation plays no special role in MEN. Symbolizing equivalence with → and defining ∼A inferentially as A→f, the theorems of MEN are just those of the underlying theory ME of pure material equivalence. (...) This accords with the treatment of negation in the Abelian l-group logic A of Meyer and Slaney (Abelian logic. Abstract, Journal of Symbolic Logic 46, 425–426, 1981), which also defines ∼A inferentially with no special conditions on f. The paper then concentrates on the pure implicational part AI of A, the simple logic of Abelian groups. The integers Z were known to be characteristic for AI, with every non-theorem B refutable mod some Zn for finite n. Noted here is that AI is pre-tabular, having the Scroggs property that every proper extension SI of AI, closed under substitution and detachment, has some finite Zn as its characteristic matrix. In particular FL is the extension for which n = 2 (Lewis, The structure of logic and its relation to other systems. The Journal of Philosophy 18, 505–516, 1921; Meyer and Slaney, Abelian logic. Abstract. Journal of Symbolic Logic 46, 425–426, 1981; This is an abstract of the much longer paper finally published in 1989 in G. G. Priest, R. Routley and J. Norman, eds., Paraconsistent logic: essays on the inconsistent, Philosophica Verlag, Munich, pp. 245–288, 1989). (shrink)

We show that the first order theory of the lattice $\mathscr{L}^{ (S) of finite dimensional closed subsets of any nontrivial infinite dimensional Steinitz Exhange System S has logical complexity at least that of first order number theory and that the first order theory of the lattice L(S ∞ ) of computably enumerable closed subsets of any nontrivial infinite dimensional computable Steinitz Exchange System S ∞ has logical complexity exactly that of first order number theory. Thus, for example, the lattice of (...) finite dimensional subspaces of a standard copy of $\bigoplus_\omega$ Q interprets first order arithmetic and is therefore as complicated as possible. In particular, our results show that the first order theories of the lattice L(V ∞ ) of c.e. subspaces of a fully effective ℵ 0 -dimensional vector space V∞ and the lattice of c.e. algebraically closed subfields of a fully effective algebraically closed field F ∞ of countably infinite transcendence degree each have logical complexity that of first order number theory. (shrink)

We say that a ring admits elimination of quantifiers, if in the language of rings, {0, 1, +, ·}, the complete theory of R admits elimination of quantifiers. Theorem 1. Let D be a division ring. Then D admits elimination of quantifiers if and only if D is an algebraically closed or finite field. A ring is prime if it satisfies the sentence: ∀ x ∀ y ∃ z (x = 0 ∨ y = 0 ∨ xzy ≠ 0). Theorem (...) 2. If R is a prime ring with an infinite center and R admits elimination of quantifiers, then R is an algebraically closed field. Let A be the class of finite fields. Let B be the class of 2 × 2 matrix rings over a field with a prime number of elements. Let C be the class of rings of the form $GF(p^n) \bigoplus GF(p^k)$ such that either n = k or g.c.d. (n, k) = 1. Let D be the set of ordered pairs (f, Q) where Q is a finite set of primes and f: Q → A ∪ B ∪ C such that the characteristic of the ring f(q) is q. Finally, let E be the class of rings of the form $\bigoplus_{q \in Q}f(q)$ for some (f, Q) in D. Theorem 3. Let R be a finite ring without nonzero trivial ideals. Then R admits elimination of quantifiers if and only if R belongs to E. Theorem 4. Let R be a ring with the descending chain condition of left ideals and without nonzero trivial ideals. Then R admits elimination of quantifiers if and only if R is an algebraically closed field or R belongs to E. In contrast to Theorems 2 and 4, we have Theorem 5. If R is an atomless p-ring, then R is finite, commutative, has no nonzero trivial ideals and admits elimination of quantifiers, but is not prime and does not have the descending chain condition. We also generalize Theorems 1, 2 and 4 to alternative rings. (shrink)

A chain-closed field is defined as a chainable field (i.e. a real field such that, for all n ∈ N, Σ K2n+1 ≠ Σ K2n) which does not admit any "faithful" algebraic extension, and can also be seen as a field having a Henselian valuation ν such that the residue field K/ν is real closed and the value group ν K is odd divisible with |ν K/2ν K| = 2. If K admits only one such valuation, we show that f (...) ∈ K(X) is in $\mathbf{\Sigma} K(X)^{2n} \operatorname{iff}$ for any real algebraic extension L of $K, "f(L) \subseteq \mathbf{\Sigma}L^{2n}"$ holds. The conclusion is also true for K = R((t)) (a chainable but not chain-closed field), and in the case n = 1 it holds for several variables and any real field K. (shrink)

We show how to extract effective bounds Φ for $\bigwedge u^1 \bigwedge v \leq_\gamma tu \bigvee w^\eta G_0$ -sentences which depend on u only (i.e. $\bigwedge u \bigwedge v \leq_\gamma tu \bigvee w \leq_\eta \Phi uG_0$ ) from arithmetical proofs which use analytical assumptions of the form \begin{equation*}\tag{*}\bigwedge x^\delta\bigvee y \leq_\rho sx \bigwedge z^\tau F_0\end{equation*} (γ, δ, ρ, and τ are arbitrary finite types, η ≤ 2, G0 and F0 are quantifier-free, and s and t are closed terms). If τ (...) ≤ 2, (*) can be weakened to $\bigwedge x^\delta, z^\tau\bigvee y \leq_\rho sx \bigwedge \tilde{z} \leq_\tau z F_0$ . This is used to establish new conservation results about weak König's lemma. Applications to proofs in classical analysis, especially uniqueness proofs in approximation theory, will be given in subsequent papers. (shrink)

Peter van Inwagen and Colin McGinn hold that there are strong arguments for strict incompatibilism, i.e. for the claim that the free will thesis (F) is inconsistent not just with determinism but with the negation of determinism as well. Interestingly, both authors deny that these arguments are apt to justify the claim that (F) is false. I argue that van Inwagen and McGinn are right in taking the fact that epistemic commitment to (F) is deeply rooted in common sense to (...) cast doubt on arguments to the conclusion that (F) is false. However, instead of declaring free will to be a mystery (van Inwagen) or claiming that the problem of free will amounts to a problem whose correct solution is cognitively closed to human intellect (McGinn), I propose to simply view the problem of free will as a hard problem – its hardness being due to the fact that it involves a large variety of concepts whose correct explication is philosophically moot. (shrink)

Open peer commentary on the article “Observing Environments” by Hugo F. Alrøe & Egon Noe. Upshot: Complementary to Alrøe and Noe’s discussion of constructivist notions of environment, world, etc., this commentary addresses the closely-related notion of agency in constructivist theories – in particular, the question of what would be required for artificial agency – and identifies open questions and fundamental disagreements among constructivist theorists.

Synaesthesia is a condition in which one type of stimulation evokes the sensation of another, as when the hearing of a sound produces photisms, i.e. mental percepts of colours. R is a 20 year old colour blind subject who, in addition to the relatively common grapheme-colour synaesthesia, presents a rarely reported cross modal perception in which a variety of visual stimuli elicit aura-like percepts of colour. In R, photisms seem to be closely related to the affective valence of stimuli and (...) typically bring out a consistent pattern of emotional responses. The present case study suggests that colours might be an intrinsic category of the human brain. We developed an empirical methodology that allowed us to study the subject's otherwise inaccessible phenomenological experience. First, we found that R shows a Stroop effect (delayed response due to interference) elicited by photisms despite the fact that he does not show a regular Stroop with real colours. Secondly, by manipulating the colour context we confirmed that colours can alter R's emotional evaluation of the stimuli. Furthermore, we demonstrated that R's auras may actually lead to a partially inverted emotional spectrum where certain stimuli bring out emotional reactions opposite to the normal ones. These findings can only be accounted for by considering R's subjective colour experience or qualia. Therefore the present paper defends the view that qualia are a useful scientific concept that can be approached and studied by experimental methods. (shrink)

We present a canonical form for definable subsets of algebraically closed valued fields by means of decompositions into sets of a simple form, and do the same for definable subsets of real closed valued fields. Both cases involve discs, forming "Swiss cheeses" in the algebraically closed case, and cuts in the real closed case. As a step in the development, we give a proof for the fact that in "most" valued fields F, if f(x),g(x) ∈ F[ x] and v is (...) the valuation map, then the set {x : v(f(x)) ≤ v(g(x))} is a Boolean combination of discs; in fact, it is a finite union of Swiss cheeses. The development also depends on the introduction of "valued trees", which we define formally. (shrink)

Focusing on Truth explores the question of what truth is, balancing historical with issue-orientated discussion. The book offers a comprehensive survey of all the major theories of truth. Lawrence Johnson investigates a number of closely related matters of truth in his inquiry, such as: What sorts of things are true or false? What is attributed to them when they are said to be true or false? What do facts have to do with truth? What can we learn from previous theories? (...) The book opens with an analysis of the coherence theory of truth and then the correspondence theory of truth, as developed by Moore, Russell and Wittgenstein. Through a study of the semantic conceptions of truth, the author reveals that an adequate theory of truth must take account of the pragmatics of person, purpose, and circumstance. A full understanding of facts and truth bearers is considered central to Johnson's criticism of the opposing truth theories of J. L. Austin and P. F. Strawson. Drawing on the merits of these theories and others, while identifying their deficiencies, Johnson presents a new account of truth, based on the correlation of referential foci and the use of linguistic conventions. This account is defended as being adequate to meet the legitimate demands made on a theory of truth. Johnson argues that the account leaves scope for statements of many different sorts to be true in their own widely varying ways, without the existence of a need to posit fundamentally different kinds of truth. (shrink)

Continuous recordings of brain electrical activity were obtained from a group of 176 patients throughout surgical procedures using general anesthesia. Artifact-free data from the 19 electrodes of the International 10/20 System were subjected to quantitative analysis of the electroencephalogram (QEEG). Induction was variously accomplished with etomidate, propofol or thiopental. Anesthesia was maintained throughout the procedures by isoflurane, desflurane or sevoflurane (N = 68), total intravenous anesthesia using propofol (N = 49), or nitrous oxide plus narcotics (N = 59). A set (...) of QEEG measures were found which reversibly displayed high heterogeneity of variance between four states as follows: (1) during induction; (2) just after loss of consciousness (LOC); (3) just before return of consciousness (ROC); (4) just after ROC. Homogeneity of variance across all agents within states was found. Topographic statistical probability images were compared between states. At LOC, power increased in all frequency bands in the power spectrum with the exception of a decrease in gamma activity, and there was a marked anteriorization of power. Additionally, a significant change occurred in hemispheric relationships, with prefrontal and frontal regions of each hemisphere becoming more closely coupled, and anterior and posterior regions on each hemisphere, as well as homologous regions between the two hemispheres, uncoupling. All of these changes reversed upon ROC. Variable resolution electromagnetic tomography (VARETA) was performed to localize salient features of power anteriorization in three dimensions. A common set of neuroanatomical regions appeared to be the locus of the most probable generators of the observed EEG changes. (shrink)

This paper contrasts two information-theoretic approaches to statistical explanation: namely, (1) an analysis, which originated in my earlier research on problems of testing stochastic models of learning, based on an entropy-like measure of expected transmitted-information (and here referred to as the Expected-Information Model), and (2) the analysis, which was proposed by James Greeno (and which is closely related to Wesley Salmon's Statistical Relevance Model), based on the information-transmitted-by-a-system. The substantial differences between these analyses can be traced to the following basic (...) difference. On Greeno's view, the essence of explanation lies in the relevance relations expressed by the conditional probabilities that relate the explanans variables to the explanandum variables; on my view, in contrast, the essence of explanation lies in theories viewed as hypothetical structures which deductively entail conditional probability distributions linking the explanans variables and the explanandum variables. The explanatory power of a stochastic theory is identified with information (regarding the values of explanandum variables) which is "absorbed from" the explanans variables. While other information which is "absorbed from" the explanandum variables (through the process of parameter estimation, for example) reflects descriptive power of the theory. I prove that Greeno's measure of transmitted information is a limiting special case of the E-I model, but that the former, unlike the latter, makes no distinction between explanatory power and descriptive power. (shrink)

Annotated logics were introduced by V.S. Subrahmanian as logical foundations for computer programming. One of the difficulties of these systems from the logical point of view is that they are not structural, i.e., their consequence relations are not closed under substitutions. In this paper we give systems of annotated logics that are equivalent to those of Subrahmanian in the sense that everything provable in one type of system has a translation that is provable in the other. Moreover these new systems (...) are structural. We prove that these systems are weakly congruential, namely, they have an infinite system of congruence 1-formulas. Moreover, we prove that an annotated logic is algebraizable (i.e., it has a finite system of congruence formulas,) if and only if the lattice of annotation constants is finite. (shrink)

Unlike standard modal logics, many dynamic epistemic logics are not closed under uniform substitution. A distinction therefore arises between the logic and its substitution core, the set of formulas all of whose substitution instances are valid. The classic example of a non-uniform dynamic epistemic logic is Public Announcement Logic (PAL), and a well-known open problem is to axiomatize the substitution core of PAL. In this paper we solve this problem for PAL over the class of all relational models with infinitely (...) many agents, PAL-K_omega, as well as standard extensions thereof, e.g., PAL-T_omega, PAL-S4_omega, and PAL-S5_omega. We introduce a new Uniform Public Announcement Logic (UPAL), prove completeness of a deductive system with respect to UPAL semantics, and show that this system axiomatizes the substitution core of PAL. (shrink)

Fred Dretske's "Knowledge and the Flow of Information" is an extended attempt to develop a philosophically useful theory of information. Dretske adapts central ideas from Shannon and Weaver's mathematical theory of communication, and applies them to some traditional problems in epistemology. In doing so, he succeeds in building for philosophers a much-needed bridge to important work in cognitive science. The pay-off for epistemologists is that Dretske promises a way out of a long-standing impasse -- the Gettier problem. He offers an (...) alternative model of knowledge as information-based belief, which purports to avoid the problems justificatory accounts face. This essay looks closely at Dretske's theory. I argue that while the information-theoretic framework is attractive, it does not provide an adequate account of knowledge. And there seems to be no way of tightening the theory without introducing some version of a theory of justification -- the very notion Dretske's theory was designed to avoid. (shrink)