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nÃo hà / This thesis aims facing the skeptical argument classic type from the contrastivist knowledge theory. The problem we will approach is when we accept the epistemic logic principle called closing principle. The principle states that knowledge is closed under implication and seems to regulate the way we expand our ordinary knowledge. Basically the closure affirms that for every epistemic subject S, target proposition p and logic Contrary q, If S knows that p and S knows that p logically implies q, so S knows that q. The problem arises when the contrary logic is a skeptical hypothesis, a hypothesis we can't know. Operating a modus tollens in the beginning closure a skeptic concludes logically that we can't know anything. To contextualize the skeptical problem contrastive solution problem that makes uses of closing we will show two theories treatment that will serve as preliminaries. The first is Fred Dretske's Relevant Alternatives Theory and the secondd is David Lewis' Contextualism. Dretske acknowledged accepting closure means surrendering to skepticism, for this reason tried to solve the problem rejecting the closing validity. The Closure rejection by Dretske, however, was considered ad hoc, therefore, unable to solve the problem. David Lewis contextualist solution, however, accepts the closure principle validity and seeks problem resolution by accusing the skeptic of misunderstand as to semantic term know. For Lewis, "knowledge" is an indexical term and , as such, undergoes contextual (semantic and epistemic) variations. Understand adequately the knowledge indexicality, for the contextualist, will show the paradox is only apparent. We will show Lewis theory advantages, but we will also show that it is unsatisfactory to solve skepticism problem. We will defend, finally, that the theory that best accommodates ordinary knowledge against skeptical arguments is Jonathan Schaffer's Contrastivism. The contrastivist theory will look to dodge the problem appealing to an epistemic revisionism. For Schaffer, the knowledge relation is essentially ternary and when we look at the skeptic puzzle by contrastivist bias we will perceive the problem is mitigated, that is, it is weakened in a most intuitive way than Dretske and Lewis theories. The contrastivist theory will defend, in an innovative way, that ordinary knowledge is compatible with skeptical doubt. / Esta tese tem por objetivo enfrentar um tipo clÃssico de argumento cÃtico a partir da teoria contrastivista do conhecimento. O problema que abordaremos surge quando aceitamos o princÃpio de lÃgica epistÃmica chamado princÃpio de fechamento. O princÃpio afirma que o conhecimento à fechado sob implicaÃÃo e parece regular o modo como expandimos nosso conhecimento ordinÃrio. Basicamente o fechamento afirma que para todo sujeito epistÃmico S, proposiÃÃo alvo p e contrÃria lÃgica q, se S sabe que p e S sabe que p implica logicamente q, entÃo S sabe que q. O problema surge quando a contrÃria lÃgica à uma hipÃtese cÃtica, uma hipÃtese que nÃo podemos conhecer. Operando um modus tollens no princÃpio de fechamento o cÃtico conclui logicamente que nÃo podemos conhecer qualquer coisa. Para contextualizar a soluÃÃo contrastivista do problema cÃtico que faz uso do fechamento apresentaremos o tratamento de duas teorias que nos servirÃo de preliminares. A primeira à a Teoria das Alternativas Relevantes de Fred Dretske e a segunda à o Contextualismo de David Lewis. Dretske reconheceu que aceitar o fechamento significa se render ao ceticismo, por esta razÃo tentou resolver o problema rejeitando a validade do fechamento. A rejeiÃÃo do fechamento por Dretske, entretanto, foi considerada ad hoc e, por isso, incapaz de resolver o problema. A soluÃÃo contextualista de David Lewis, entretanto, aceita a validade do princÃpio do fechamento e busca resolver o problema acusando o cÃtico de equivocar-se quanto à semÃntica do termo conhecer. Para Lewis o âconhecimentoâ à um termo indexical e, como tal, sofre variaÃÃes (semÃnticas e epistÃmicas) contextuais. Compreender adequadamente a indexicalidade do conhecimento, para o contextualista, mostrarà que o paradoxo à apenas aparente. Mostraremos as vantagens da teoria de Lewis, mas mostraremos tambÃm que ela à insatisfatÃria para resolver o problema do ceticismo. Defenderemos, por fim, que a teoria que melhor acomoda o conhecimento ordinÃrio frente aos argumentos cÃticos à o Contrastivismo de Jonathan Schaffer. A teoria contrastivista buscarà esquivar-se do problema apelando para um revisionismo epistÃmico. Para Schaffer, a relaÃÃo de conhecimento à essencialmente ternÃria e quando olharmos para o puzzle cÃtico pelo viÃs contrastivista perceberemos que o problema à mitigado, ou seja, à enfraquecido de um modo mais intuitivo do que as teorias de Dretske e Lewis. A teoria contrastivista defenderÃ, de maneira inovadora, que o conhecimento ordinÃrio à compatÃvel com a dÃvida cÃtica.

External world skeptics argue that we have no knowledge of the external world. Contextualist theories of knowledge attempt to address the skeptical problem by maintaining that arguments for skepticism are effective only in certain contexts in which the standards for knowledge are so high that we cannot reach them. In ordinary contexts, however, the standards for knowledge fall back down to reachable levels and we again are able to have knowledge of the external world. In order to address the objection that contextualists confuse the standards for knowledge with the standards for warranted assertion, Keith DeRose appeals to the knowledge account of warranted assertion to argue that if one is warranted in asserting p, one also knows p. A skeptic, however, can maintain a context-invariant view of the knowledge account of assertion, in which case such an account would not provide my help to contextualism.

I argue that despite the fact that there can be no strong refutation of skepticism it remains that ignoring skeptical hypotheses and relying on one’s sensory experience are both sound epistemic practices. This argument comes in the form of arguing that we are justified in ignoring skeptical hypotheses on the grounds that (1) they are merely logically possible, and (2) the merely logically possible is rarely relevant in the context of everyday life. I suggest that (2) is true on the grounds that the context of everyday life is one in which our epistemic pursuit of truth is mixed with other pragmatic goals. The result of this mix is that the pursuit of truth can conflict with our goal of avoiding error in such a way that we must choose to prioritize one goal over the other. The above choice implies that skepticism comes at an epistemic cost not acknowledge in the contemporary literature on external world skepticism. This epistemic cost of skepticism means that the relative risk of error involved in relying on sensory experience is not as epistemically problematic as has often been assumed. These considerations allow an anti-skeptical position in which relying on sensory experience is prima-facie justified despite the possibility of being a brain in a vat. In this paper I explore what such a position might look like and what the implications of such a view might be for relevant alternatives positions, the closure debate, and the concept of differing epistemic perspectives in contemporary epistemology.

SOUZA, Luis Fernando dos Santos. Desarmando o puzzle cético: uma defesa da epistemologia contrastivista. 2016. 160f. – Tese (Doutorado) – Universidade Federal do Ceará, Programa de Pós-Graduação em Filosofia, Fortaleza (CE), 2016. / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2017-07-10T17:10:24Z No. of bitstreams: 1 2016_tese_lfssouza.pdf: 1448839 bytes, checksum: f3b0a151ca978022517d4e18ba7a8f98 (MD5) / Rejected by Gustavo Daher (gdaherufc@hotmail.com), reason: fd on 2017-07-11T11:07:39Z (GMT) / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2017-07-11T11:09:44Z No. of bitstreams: 1 2016_tese_lfssouza.pdf: 1041996 bytes, checksum: 436db74ca13b099559c9d9da4f8fb510 (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2017-07-25T12:32:06Z (GMT) No. of bitstreams: 1 2016_tese_lfssouza.pdf: 1041996 bytes, checksum: 436db74ca13b099559c9d9da4f8fb510 (MD5) / Made available in DSpace on 2017-07-25T12:32:06Z (GMT). No. of bitstreams: 1 2016_tese_lfssouza.pdf: 1041996 bytes, checksum: 436db74ca13b099559c9d9da4f8fb510 (MD5) Previous issue date: 2016 / Esta tese tem por objetivo enfrentar um tipo clássico de argumento cético a partir da teoria contrastivista do conhecimento. O problema que abordaremos surge quando aceitamos o princípio de lógica epistêmica chamado princípio de fechamento. O princípio afirma que o conhecimento é fechado sob implicação e parece regular o modo como expandimos nosso conhecimento ordinário. Basicamente o fechamento afirma que para todo sujeito epistêmico S, proposição alvo p e contrária lógica q, se S sabe que p e S sabe que p implica logicamente q, então S sabe que q. O problema surge quando a contrária lógica é uma hipótese cética, uma hipótese que não podemos conhecer. Operando um modus tollens no princípio de fechamento o cético conclui logicamente que não podemos conhecer qualquer coisa. Para contextualizar a solução contrastivista do problema cético que faz uso do fechamento apresentaremos o tratamento de duas teorias que nos servirão de preliminares. A primeira é a Teoria das Alternativas Relevantes de Fred Dretske e a segunda é o Contextualismo de David Lewis. Dretske reconheceu que aceitar o fechamento significa se render ao ceticismo, por esta razão tentou resolver o problema rejeitando a validade do fechamento. A rejeição do fechamento por Dretske, entretanto, foi considerada ad hoc e, por isso, incapaz de resolver o problema. A solução contextualista de David Lewis, entretanto, aceita a validade do princípio do fechamento e busca resolver o problema acusando o cético de equivocar-se quanto à semântica do termo conhecer. Para Lewis o “conhecimento” é um termo indexical e, como tal, sofre variações (semânticas e epistêmicas) contextuais. Compreender adequadamente a indexicalidade do conhecimento, para o contextualista, mostrará que o paradoxo é apenas aparente. Mostraremos as vantagens da teoria de Lewis, mas mostraremos também que ela é insatisfatória para resolver o problema do ceticismo. Defenderemos, por fim, que a teoria que melhor acomoda o conhecimento ordinário frente aos argumentos céticos é o Contrastivismo de Jonathan Schaffer. A teoria contrastivista buscará esquivar-se do problema apelando para um revisionismo epistêmico. Para Schaffer, a relação de conhecimento é essencialmente ternária e quando olharmos para o puzzle cético pelo viés contrastivista perceberemos que o problema é mitigado, ou seja, é enfraquecido de um modo mais intuitivo do que as teorias de Dretske e Lewis. A teoria contrastivista defenderá, de maneira inovadora, que o conhecimento ordinário é compatível com a dúvida cética.

Une nouvelle tentative pour faire face au défi sceptique est menée depuis une quarantaine d’années. Cette tentative repose sur une théorie de la connaissance centrée sur la notion d’alternatives pertinentes. La thèse se propose de montrer les faiblesses de cette théorie, même lorsqu’elle s’appuie sur l’appareillage des mondes possibles, et suggère que le scepticisme demeure la meilleure position épistémologique. Dans le premier chapitre on passe en revue une série de difficultés liées au sujet des alternatives pertinentes et l'on essaye d'argumenter en faveur de l'idée qu'il n'y a peut-être pas, finalement, de moyens en quelque sorte objectifs pour établir quelles sont les alternatives pertinentes relativement à une situation quelconque. À partir du deuxième chapitre, il est procédé à une analyse critique des tentatives de certains auteurs qui se sont servis, pour élaborer leurs propres conceptions bien précises, du langage des mondes possibles. Dans le deuxième chapitre, l'on se concentre surtout sur la question du degré de proximité qu'un monde possible donné doit exhiber pour être considéré comme suffisamment proche du monde actuel et l'on essaye de montrer qu'il n’est probablement pas possible de tracer d'une manière non arbitraire une ligne de démarcation entre ces mondes possibles qu’on peut ignorer et ceux qu’on ne peut ignorer dans nos attributions de connaissance. Dans le troisième chapitre, l'on se concentre surtout sur la question des critères qui devraient guider nos évaluations de proximité et l'on essaye de montrer le caractère discutable de n'importe quelle règle visant à établir quels seraient ces critères-là. / Over the last forty years, a new attempt to answer to the skeptic challenge has been proposed. This attempt is based on a theory of knowledge, which is grounded on the notion of relevant alternative. My dissertation aims to show the problems of such a theory, even when formulated in terms of possible worlds, and suggests that in the end skepticism remains the best epistemological option. In the first chapter, I will offer a discussion of the issue of relevant alternatives, and I will argue in favor of the idea that perhaps there are no objective criteria to establish which are the relevant alternatives with respect to a certain given situation. In the second chapter, I will propose a critical analysis of the attempts of some philosophers to formulate their own proposals in the language of possible worlds. In particular, I will focus on the issue of the proximity degree that a certain possible world must have in order to be considered as sufficiently closed to the real world, and I will try to show that perhaps it is not possible to draw a sharp line of demarcation between those possible worlds that we can ignore and those that we must take into account in our attribution of knowledge. In the third chapter, I will critically discuss the criteria that should guide our evaluations about proximity, and I will show the problematic aspects of any rule aimed to establish which these criteria in effect should be.

The increasingly observable excess capacity in the fixed networks calls into question the established long-standing pricing standards for wholesale services based on forward-looking long-run incremental costs (FL-LRAIC). The FL-LRAIC standard has worked quite well in expanding markets, although even there price-squeeze problems have appeared. In contracting markets the price-squeeze issue, however, becomes paramount and lower prices both at the wholesale and retail levels would be efficient. This would favor a retail-minus approach (RM) under long-term contraction. Because both expansion and contraction could be relevant in the future, we propose an optional approach based on the wholesale price formula p = min(FL-LRAIC, RM). This will generally protect alternative competitors against price-squeeze while at the same time allowing the fixed-network incumbent full downward price flexibility. It also protects alternative competitors and end users against excessively high prices. Hence, implementing this option successfully at wholesale level would eliminate the need to regulate retail markets. The combination of RM and FL-LRAIC seems to be most realistic, because it is relatively simple and internationally partly tested already. We show that this option is superior to FL-LRAIC or RM alone and to other approaches, such as short-run marginal costs. We also consider a possible combination with capacity-based charging, which may have particular merits for converged services in next generation networks (NGNs). / Series: Working Papers / Research Institute for Regulatory Economics