In this thesis, I investigate different Contextualist strategies for responding to the sceptical Argument from Ignorance (AI). Such responses are notable for not challenging the Principle of Epistemic Closure (widely held to be primarily responsible for the argument's conclusion). I am concerned to explore Contextualism's ability to respond to AI in a way which does not result in an uncomfortable concession to scepticism. In Part 1, I discuss Semantic Contextualism; in Part 2, I investigate how AI fares with regards to transmission of warrant when AI utilises either invariantist or Contextualist presuppositions; and in Part 3, I discuss whether Epistemic Contextualism succeeds where Semantic Contextualism fails, arguing that it does. I conclude with an endorsement of Epistemic Contextualism. Part 1: I demonstrate that Semantic Contextualism, of which I will consider three different varieties (externalist, internalist, presuppositionalist), is overly concessive to scepticism because it results in the following four difficulties: (1) knowledge attributions of the form 'I know/S knows that ~B' (where B stands for the sceptical brain-in-a-vat hypothesis) are invariably false; (2) the sceptical context is extremely easy to install; (3) scepticism is said to result from entirely ordinary epistemic practices and; (4) the sceptical context is taken to be an entirely legitimate context of ascription. I conclude Part 1 with the claim that Semantic Contextualism is overly concessive to scepticism. Part 2: Previously, Moore's Proof of an External World has been diagnosed with failing to transmit the warrant on offer for its premises to its conclusion. I argue that it is possible likewise to charge AI with transmission failure but that this cannot be done when some of the conceptual resources of Contextualism are brought to bear on AI. I show that AI can be charged with transmission failure when it is interpreted in support of invariantist (context-unrestricted) scepticism and that only when it is viewed as an argument for a context-restricted form of scepticism does it succeed in transmitting warrant. In this way, the sceptical consequences of AI are considerably reduced. Part 3: The conceptual resources newly deployed in Part 2, which show that a context-restricted, as opposed to invariantist, interpretation of AI can succeed in transmitting warrant, are borrowed from Michael Williams' Epistemic form of Contextualism. But is this form of Contextualism as concessive to scepticism as I showed Semantic Contextualism to be? I argue that it does not represent an overly concessive position vis-a-vis scepticism and therefore represents a superior Contextualist position and response to scepticism. To establish this conclusion, I interrogate the strategy and main elements of Williams' theoretical diagnosis of scepticism and his resultant version of Contextualism so as to determine the extent to which scepticism can be allayed by it. Particular attention is paid to specifying issues that Williams does not discuss, most prominently how the sceptical context has to be understood in order for it to resist his theoretical diagnosis of scepticism and what makes toleration of such resistance by context-bound scepticism reasonable. I conclude my thesis with an endorsement of Williams' Epistemic Contextualism.

Made available in DSpace on 2015-05-14T12:11:47Z (GMT). No. of bitstreams: 1 ArquivoTotalStanley.pdf: 851354 bytes, checksum: 234d62287f1fecde25a5e081c1327260 (MD5) Previous issue date: 2013-05-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Epistemic closure is the principle that says that knowledge is closed under known entailment. If an agent, S, knows that some proposition P is the case and, beside of that, equally knows that P logically implies another proposition, say, Q, then S must also know that Q is the case. Thus, if S believes Q in a strong base provided by the premisses, then he must also know that Q is the case. The present work is a logical-epistemological study of epistemic closure principles, based on the notion of contingent unknowability. Noting that the problem of epistemic closure is open and that the common attempts in contemporary mainstream epistemology seem to ignore the results of the formal epistemology about the relationship between these principles and the property of logical omniscience, our main goal is to provide a strategy for an epistemological analysis of epistemic closure principles that consider these results, taking into account the purpose of applicability of a particular closure principle, according to the situation and the agents that one wants to model. An example of this strategy will be given when analyzing closure principles from the perspective of agents that reason about contingently unknowable propositions. Our hypothesis is that, in this particular application, certain closure principles do not hold. / O "fecho epistêmico'' é o princípio que afirma que o conhecimento é fechado sob implicação. Se um agente S qualquer sabe que uma proposição P é o caso e, além disso, igualmente sabe que P implica logicamente outra proposição, Q, então o agente em questão também deve saber que Q é o caso. Assim, se S acredita em Q a partir da base segura fornecida pelas premissas, então ele também deve saber que Q é o caso. Este é um estudo lógico-epistemológico de princípios de fecho epistêmico com base na noção de incognoscibilidade contingente. Constatando que o problema do fecho epistêmico está em aberto e que as tentativas mais comuns na epistemologia mainstream contemporânea parecem ignorar os resultados da epistemologia formal sobre a relação entre estes princípios e a propriedade de onisciência lógica, nosso objetivo principal é oferecer uma estratégia para uma análise epistemológica de princípios de fecho epistêmico que considere estes resultados; que leve em conta a pretensão de aplicabilidade de um determinado princípio de fecho, segundo a situação e os agentes que se pretende modelar. Um exemplo dessa estratégia será dado ao se analisar princípios de fecho na perspectiva de agentes conjecturadores de proposições contingentemente incognoscíveis. Nossa hipótese é a de que, nesta aplicação, certos princípios de fecho não valem.

It is widely believed that we have immediate, introspective access to the content of our own thoughts. This access is assumed to be privileged in a way that our access to the thought content of others is not. It is also widely believed that, in many cases, thought content is individuated according to properties that are external to the thinker's head. I will refer to these theses as privileged access and content externalism, respectively. Though both are widely held to be true, various arguments have been put forth to the effect that they are incompatible. This charge of incompatibilism has been met with a variety of compatibilist responses, each of which has received its own share of criticism. In this thesis, I will argue that a contrastive account of self-knowledge is a novel compatibilist response that shows significant promise.

This thesis concerns approaches to solving the problem of paradoxical sceptical arguments from ignorance within contemporary epistemology. In chapter 1, I critically discuss three frameworks for approaching the sceptical problem, and argue that theoretical responses are unsatisfactory. In chapter 2, I critically examine recent accounts of sceptical hypotheses, and argue against them on the grounds of generality, and in favour of my own account. In chapter 3, I critically examine recent accounts of the epistemic principles underwriting sceptical arguments from ignorance, and argue against them on the grounds of generality, and in favour of my own account. In chapter 4, I critically evaluate the adequacy of resolutions to sceptical paradoxes suggested by three prominent versions of epistemological contextualism. In chapter 5, I examine a central objection to the error theories implied by contextualist resolutions of sceptical paradoxes, which focuses on the notion of semantic blindness. Two assessments of the objection are set out, and contextualist responses to each. I argued that considerations of semantic blindness count against contextualist resolutions of sceptical paradoxes in favour of invariantists. In chapter 6, I assess the potential for an invariantist to provide an adequate error-theory concerning, and resolving, sceptical paradoxes. I critically assess approaches based on aspects of the heuristics and biases paradigm, and of dual-process theories of mindreading. I propose, instead, a novel anti-sceptical error-theory in terms of the default-interventionist model of dual-process theory of judgement and reasoning, together with my conclusions from chapters 2 and 3.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The identification and analysis of epistemic principles have enabled significant gains in the study of skepticism in recent decades; this does not mean that we are near a consensus about which principles should be accepted. Taking p for any proposition that we normally accept to be known, like here is a hand , and h for a skeptical scenario such p is not true, but just a illusion projected in my mind , the skeptical argument can be formalized as follows: (1) If S knows that p, then S knows that ~h; (2) S doesn t know that ~h, then (3) S doesn t know that p. The first chapter of this text presents a comprehensive analysis of this argument, where is pointed out that its cogency can be defended from a valid version of the epistemic closure principle. The second chapter deals with the antiskeptical strategy advocated by Fred Dretske, which attempts to refute the skeptic arguing against its first premise, by rejecting the closure principle. At the end of this chapter, it is argued that the Dretske's arguments fail to fulfill their goal, collapsing in the face of relevant objections. Finally, the third chapter examines the answer to the skeptic presented by Peter Klein. Based on a more sophisticated understanding of the epistemic closure principle, Klein suggests that the skeptic cannot build a plausible argument for (2). It is argued that this analysis of the problem is adequate and resists criticism of his objectors. / A identificação e a análise de princípios epistêmicos têm possibilitado ganhos significativos no estudo do ceticismo nas últimas décadas; contudo isso não significa que estejamos próximos de um consenso sobre quais princípios devam ser aceitos. Entendendo p como qualquer proposição que geralmente admitiríamos saber, como aqui há uma mão , e h como algum cenário cético incompatível com a verdade de p, tal como p não é verdade mas apenas uma ilusão projetada em minha mente , o argumento cético é comumente assim formalizado: (1) Se S sabe que p, então S sabe que ~h; (2) S não sabe ~h, logo, (3) S não sabe que p. O primeiro capítulo desta dissertação é destinado à análise detalhada das premissas desse argumento, onde é apontado que sua cogência pode ser mantida a partir da defesa de uma versão válida do princípio de fechamento epistêmico. O segundo capítulo trata da estratégia anticética defendia por Fred Dretske, que busca refutar o ceticismo atacando sua primeira premissa, rejeitando o princípio de fechamento. Ao término deste capítulo, é defendido que os argumentos de Dretske falham no cumprimento de seu objetivo, sucumbindo frente a importantes objeções. Finalmente, no terceiro capítulo, discorre-se sobre a resposta para o cético apresentada por Peter Klein. Partindo de uma compreensão mais sofisticada do princípio de fechamento epistêmico, Klein sinaliza que o cético não consegue construir um argumento plausível para (2). Defende-se que essa análise do problema é adequada e resiste às críticas de seus objetores.