A Dempster-Shafer theory inspired logic.

Issues of formalising and interpreting epistemic uncertainty have always played a prominent role in Artificial Intelligence. The Dempster-Shafer (DS) theory of partial beliefs is one of the most-well known formalisms to address the partial knowledge. Similarly to the DS theory, which is a generalisation of the classical probability theory, fuzzy logic provides an alternative reasoning apparatus as compared to Boolean logic. Both theories are featured prominently within the Artificial Intelligence domain, but the unified framework accounting for all the aspects of imprecise knowledge is yet to be developed. Fuzzy logic apparatus is often used for reasoning based on vague information, and the beliefs are often processed with the aid of Boolean logic. The situation clearly calls for the development of a logic formalism targeted specifically for the needs of the theory of beliefs. Several frameworks exist based on interpreting epistemic uncertainty through an appropriately defined modal operator. There is an epistemic problem with this kind of frameworks: while addressing uncertain information, they also allow for non-constructive proofs, and in this sense the number of true statements within these frameworks is too large. In this work, it is argued that an inferential apparatus for the theory of beliefs should follow premises of Brouwer's intuitionism. A logic refuting tertium non daturìs constructed by defining a correspondence between the support functions representing beliefs in the DS theory and semantic models based on intuitionistic Kripke models with weighted nodes. Without addional constraints on the semantic models and without modal operators, the constructed logic is equivalent to the minimal intuitionistic logic. A number of possible constraints is considered resulting in additional axioms and making the proposed logic intermediate. Further analysis of the properties of the created framework shows that the approach preserves the Dempster-Shafer belief assignments and thus expresses modality through the belief assignments of the formulae within the developed logic

Three Conceptions of Modal Realism

The thesis is divided into three sections. The first of these is a critique of the conceptions of modal realism due to Lewis; the second, a critique of that due to McGinn. The third section comprises the development and initial evaluation of a third conception of moral realism which I term secondary modal realism. In Section One of the thesis [Ch.1- Ch.5] I argue against the acceptability of the objectual modal realism of David Lewis and I argue (tentatively) for one theory of the meaning of possible world statements which is consistent with this denial of the existence of possible worlds. Chapters 1- 4 concern the former argument, Ch.5 concerns the latter. In Ch.1, I argue that there is no genuine semantic utility afforded by the adoption of realism about possible worlds. The case is (i) that the genuine semantical utility which does accrue via the ontological commitment to possible worlds can be had without that ontological commitmment and (ii) that other claims to semanti utility which are associated with possible world semantics do not reflect legitimate semantic-explanatory interests. The main part of the discussion of objectual realism - constituted by Chapters 2, 3 & 4 - takes a different turn. Since Lewis is fond of comparing his modal realism to realism about the entities of mathematics, I attempt to show that, on both epistemological and metaphysical grounds, the comparison is quite unfavourable for objectual modal realism. In Ch.2, I defend the objectual modal realist's right to an a priori epistemology of modality in face of Benaceraffs dilemma, but, it is argued in Ch.3, even granted a priority, there is still a serious epistemological difficulty since the internal epistemology of modal realism which is proposed by Lewis is seriously flawed. In Ch.4, it is argued that there is at least one important metaphysical consideration which militates against an ontological commitment to worlds but which does not appear to have the same impact re. mathematical ontology, viz: that the mooted possible worlds are identification- transcendent. Having made the case for anti-realism about possible worlds I am concerned in Ch.5 with the outline of a theory of the meaning of possible world statements which is consistent with this ontological position. I argue for the unacceptability of a theory, outlined by Forbes, which depends upon the claim that possible world statements do not mean what they appear to mean. I then counterpose the options of an error theory and a metaphor theory of world-talk arguing that while both of these are prima facie tenable, the latter is preferable. In Section Two of the thesis [Ch.6 - Ch.9] I deal with the non-objectual modal realism of McGinn. Having set out the salient theses of McGinn's conception of modal realism [Ch.6], the critique of this conception follows. Ch. 6: the variety and resources of anti-realisms about modality are seriously underestimated by McGinn. In particular the option of anti-realism based on the strategy of proposing a sceptical solution as a response to a sceptical paradox is ignored. Ch.7: McGinn proposes that the only defensible form of modal realism consists in endorsing the thesis of supervenience (without reduction) of the modal on the actual. However, the discussion of supervenience fails to acknowledge many of the difficulties associated with the application of supervenience and related theses in the modal case. Furthermore, there is every reason to believe that acceptance of modal/actual supervenience involves no commitment to modal realism. Ch.8: consideration of the issues that flow from the discussion of the thesis of supervenience should point towards a central question of modal epistemology i.e. whether modal knowledge is attainable by conceptual means alone. However, McGinn's discussion of supervenience leads him away from this central question and as a result he mislocates the problematic nature of modal epistemology in the claim that we cannot represent modal facts as causally explaining our knowledge of them. Ch.9:The modal realism that McGinn offers is wholly unacceptable since it provides neither a clear conception of the truth-conditions of modal statements nor any account of how we detect modalities. The realism he offers is redolent of sceptical paradox and seems ripe for an anti-realist treatment in the form of a sceptical solution. Hence, the upshot of the first two sections is that the existing conceptions of modal realism, i.e. those of Lewis and of McGinn respectively, are indefensible. In Section Three of the thesis [Ch.10 - Ch. 12] the aim is to characterize and evaluate a third conception of modal realism - secondary modal realism. This project is inspired by (i) McDowell's secondary quality conception of moral reality and (ii) the observation of crucial similarities between the failings of more traditional conceptions of moral realism and those conceptions of modal realisms dealt with above. In Ch.10, I argue that anthropocentricity as opposed to perceptibility is the feature of paradigmatic secondary properties which is an appropriately generalizable feature of secondary realism and that a proper conception of the standard of correctness for secondary property judgments facilitates the extrapolation of that standard to the cases of moral and modal judgement. (Abstract shortened by ProQuest.)

A Dempster-Shafer theory inspired logic

Issues of formalising and interpreting epistemic uncertainty have always played a prominent role in Artificial Intelligence. The Dempster-Shafer (DS) theory of partial beliefs is one of the most-well known formalisms to address the partial knowledge. Similarly to the DS theory, which is a generalisation of the classical probability theory, fuzzy logic provides an alternative reasoning apparatus as compared to Boolean logic. Both theories are featured prominently within the Artificial Intelligence domain, but the unified framework accounting for all the aspects of imprecise knowledge is yet to be developed. Fuzzy logic apparatus is often used for reasoning based on vague information, and the beliefs are often processed with the aid of Boolean logic. The situation clearly calls for the development of a logic formalism targeted specifically for the needs of the theory of beliefs. Several frameworks exist based on interpreting epistemic uncertainty through an appropriately defined modal operator. There is an epistemic problem with this kind of frameworks: while addressing uncertain information, they also allow for non-constructive proofs, and in this sense the number of true statements within these frameworks is too large. In this work, it is argued that an inferential apparatus for the theory of beliefs should follow premises of Brouwer's intuitionism. A logic refuting tertium non daturìs constructed by defining a correspondence between the support functions representing beliefs in the DS theory and semantic models based on intuitionistic Kripke models with weighted nodes. Without addional constraints on the semantic models and without modal operators, the constructed logic is equivalent to the minimal intuitionistic logic. A number of possible constraints is considered resulting in additional axioms and making the proposed logic intermediate. Further analysis of the properties of the created framework shows that the approach preserves the Dempster-Shafer belief assignments and thus expresses modality through the belief assignments of the formulae within the developed logic.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Content and Psychology

The theoretical underpinnings and practical worth of content-based, intentional, or "folk" psychology have been challenged by three distinct groups of philosophical critics in the past 15 years or so. The first group, comprised by Hilary Putnam, Tyler Burge, and other advocates of "wide" or "externalist" theories of meaning, claims that traditional psychologists have been mistaken in assuming that our beliefs, desires, and other content-laden states supervene on or inhere in our individual minds or brains. The other two groups are both "eliminative materialists," who charge that the intentional approach is inadequate and that it can or will be replaced by a completely non-interpretive discipline: either neuropsychology, in the view of Patricia and Paul Churchland, or a strictly syntactic computational psychology, according to Stephen Stich. ;This dissertation defends "notional world" or narrow intentional psychology against these charges, primarily on the strength of its practical merits, in contrast to the limitations and adverse effects of the proposed alternatives. Psychology is at least partly an applied science with a mandate to help understand and treat concrete psychological problems such as Post Traumatic Stress Disorder and depression, I argue, so any theorist who proposes to reconfigure or phase out existing approaches must be prepared to take over these duties with at least equal facility. However, whereas various "narrow" schools of psychotherapy such as Cognitive Therapy are fairly successful in this regard and show every indication of continuing to be needed for the foreseeable future, the Syntactic Theory seems to show very poor promise of being able to help relieve the distress of people with psychological disturbances, while a purely neurobiological approach is inappropriate in many cases, and tends to cause a variety of untoward and dangerous side-effects. As for the "wide" theorists with their emphasis upon the social and environmental contributions to meaning: they must acknowledge that a good deal of content is in the head; and, more importantly, by focusing on the role of the "experts" in a society's language-game, they miss the whole point of a psychological attribution, which is to understand an individual's reasons--however idiosyncratic--for acting as he or she does

Narcissism, personality and personality pathology

This thesis used the methods of differential, cognitive and theoretical psychology to investigate the relationships between pathological narcissism and maladaptive personality and behaviour in general, and to attempt the beginnings of construct validation of M. Scott Peck's proposed `evil' subtype of the DSM -IV Narcissistic Personality Disorder in particular. After a review of theoretical and empirical contributions to the psychology of narcissism, two empirical studies were conducted. In the first, joint self- report survey research using 338 subjects investigated the psychometric structure of narcissism, normal and abnormal personality, and constructs theoretically related to narcissism. Item -level exploratory principal components analysis and confirmatory factor analysis resulted in new subscales for the Narcissistic Personality Inventory. Scale -level exploratory principal components analysis of the combined questionnaires found evidence for a five - factor structure of abnormal personality. One of the five factors was related to narcissistic will to power and low agreeableness; another was related to narcissistic self - love and extraversion. Confirmatory factor analysis of a subset of the data found fair fit for the model.The second study investigated the relationships between narcissism, compartmentalisation, splitting, attribution style and response to disconfirming feedback. No evidence was found to support the hypothesis that narcissists have compartmentalised self -concepts. Moderate test -retest and alternate -form reliability data were obtained for the card -sort task used to assess compartmentalisation. No evidence was found that narcissists use splitting to translocate unwanted self -aspects onto others. Narcissistic dominance was associated with claiming personal credit for positive outcomes, while narcissistic vulnerability was associated with self -blame for negative events. Multiple regression with interaction terms indicated that the relationship between narcissism and response to disconfirming feedback is a function of other personality traits such as neuroticism, and may have opposite effects in different personalities and circumstances. Zero -order correlations suggested significant roles for splitting, narcissistic grandiosity and idealisation, and 12 NEO -PI -R facet -level variables in response to disconfirming feedback.Peck's proposed subtype of narcissistic personality disorder is theoretically distinguished from psychopathy by the use of self- deception to defend the conscience against guilt for the consequences of one's actions, rather than the absence of conscience that characterises psychopathy. Self- deception is among the most difficult and controversial topics in philosophical psychology. Theoretical chapters approached the issue with historical and literary examples, argued that splitting may be a fundamental basis of much self -deception, offered a model of malignant narcissism within the Schematic Propositional Associative Analogue Representation Systems (SPAARS) theory, and addressed the issue in the philosophy of science of whether the proposed personality disorder is a natural or social kind

Prospects for Nothing: Representing Nonbeing and the Metaphysics of Intentionality in Aquinas, Spinoza, and Leibniz

This dissertation is not a monograph but an exhibition of three independent articles I published as a doctoral student: • “On the Causal Role of Privation in Thomas Aquinas’s Metaphysics,” European Journal of Philosophy 28 (2020): 306-322. • “Spinoza on Relations,” in A Companion to Spinoza, edited by Yitzhak Y. Melamed (Oxford: Wiley-Blackwell, 2021). • “Brandom’s Leibniz,” Pacific Philosophical Quarterly 102 (2021): 73-102. The papers concern, respectively, Thomas Aquinas’s views on privation and causation; Baruch Spinoza’s views on relations; and contemporary philosopher Robert Brandom’s interpretation of Gottfried Leibniz’s metaphysical account of perceptual distinctness. In an introductory essay, I explicate the respective content of my three papers, bringing out the philosophical potential of viewing them together. I reflect on their orientation around a common theme: the possibility of thinking about what does not exist—of representing nonbeing. As I reveal, however, one message we can take away from my papers is that Aquinas, Spinoza, and Leibniz are attuned to a more specific problem: how we can represent what cannot be represented as existing. My chief aim in the introduction is to examine our thinkers’ perspectives on this question with reference to the content of my articles. The introduction concludes by suggesting how the purposeful juxtaposition of three such independently conceived, topically self-contained pieces of research can be philosophically validated