June 21, 2013 12:00am

Session 15 21 June 2013

Aristotelian Actualisms

David Yates (Power Structuralism in Ancient Ontologies Project, Corpus Christi College, University of Oxford)

 

Abstract: Aristotelian actualists think that metaphysical modality is grounded in the powers of actual things. Powers are essentially such as to manifest in various ways depending on their combinations, and they thereby make counterfactuals true. ‘David Yates could have been a scientist’ is possibly true, because various things in the history of the world—including me—have a range of powers which, had they been differently combined, would have manifested in a way that brought about my being a scientist. Aristotelian actualists take themselves to be hardcore actualists–p is possible iff somewhere in the history of the world, something has (or some things have) the power(s) to bring it about that p; and p is necessary iff nothing has the power to bring it about that Øp. The actualism is hardcore because it promises a grounding of modal truths directly in terms of powers, without appealing to possible worlds. I shall argue that the hardcore component of their actualism limits Aristotelian actualists to a very weak system of modal logic, K4. If a stronger system such as S4 or S5 is required, then they need to retreat to softcore actualism: build possible worlds out of powers and the ways in which they could manifest, then understand possibility and necessity in the usual way.

 

Session 14 7 June 2013

The Puzzle of Mental Imagery

Sara Bizarro (University of Lisbon, LanCog Group)

 

Abstract: The mental imagery debate, a debate about the nature of certain allegedly pictorial mental representations, is still undecided. On one side of the debate, we have those who argue that mental imagery is propositional in its nature, or at least a lot less pictorial than we like to think, while on the other side of the debate, we have those who defend that mental imagery is essentially pictorial in nature. In this paper, an attempt is made to clarify both positions with the examples usually brought up to illustrate them. In view of these examples, some conclusions are reached. Mental imagery is said to be not very detailed and have pictorial aspects that are similar to those that exist in regular perception. Mental imagery is also said to be cognitively permeable. Elaborate encoding across modalities is said to be more efficient than within modalities, thus supporting a dual code hypothesis of mental representation.

 

Session 13 31 May 2013

Living at the Present Moment

Fabrice Correia (University of Neuchâtel)

 

Abstract: The growing block theory and the moving spotlight theory – two of the main theories of temporal existence which take temporal passage seriously – have recently been accused of leading to a grave epistemic issue: on either view, we cannot know that it’s now now. The objection is considered by some prominent philosophers to be very powerful. I offer a precise characterisation of these views (and, in so doing, of other related views in the area like e.g. presentism), and use it to undermine the objection. The presentation is largely based on joint work with Sven Rosenkranz.

 

Session 12 17 May 2013

Ontologia da Arte: Criatividade e Bom Senso

António Lopes (University of Lisbon, LanCog Group)

 

Resumo: Que tipo de coisa é Macbeth? Se dois compositores escrevem duas partituras exactamente iguais sem o saberem, quantas obras temos? Se um poeta concebe um soneto e é atropelado fatalmente antes de o escrever, existe ou existiu um poema? Ao longo das últimas décadas, filósofos da arte e metafísicos têm apresentado perspectivas extremamente diversas, originais e surpreendentes sobre o problema de saber quais as categorias metafísicas em que melhor se encaixam as diferentes obras de arte. A profusão de teorias neste campo não só cobre a quase totalidade das categorias geralmente discutidas, como a transborda. A inovação em ontologia da arte parece querer espelhar a criatividade do seu objecto. Traçarei uma panorâmica das principais teorias ontológicas hoje discutidas, como preparação para a discussão de algumas questões meta-ontológicas e metodológicas cada vez mais na ordem do dia. Deve uma ontologia da arte descrever as concepções metafísicas constitutivas implícitas no discurso e prática artísticos, ou regimentá-las? Poderão estar erradas as crenças fundamentais dessa prática acerca da natureza dos artefactos que cria e com os quais lida? A partir de que limites uma teoria deixa de ser revisionista para passar a falhar o objecto que devia analisar? Como pano de fundo estará uma sugestão: se as questões de apreciação e valor têm a primazia na filosofia da arte, a metafísica em sentido estrito é esteticamente inerte, mesmo que isso não lhe retire o fascínio.

 

Session 11 10 May 2013

On the Logic of Fiction

Benjamin Schnieder (University of Hamburg)

 

Abstract: The content of a story consists in more than is explicitly given to its audience. In figuring out the complete content of a story, we draw all kinds of consequences from the explicitly given material. The most basic consequences are purely logical ones, so it may seem natural to assume a closure principle such as: if a proposition x belongs to the content of a fiction f, and if y is a logical consequence of x, then y belongs to the content of f as well. But if we work with the classical notion of consequence, this closure principle has notorious problems because of the possibility of inconsistent fiction.

I will explore the possibilities of defining an alternative notion of consequence, based on the notion of ground, with which the closure principle becomes more attractive.

 

Session 10 3 May 2013

O que é uma Lei da Natureza?

Eduardo Castro (Universidade da Beira Interior e LanCog Group)

 

Resumo: Comunicação sobre o estado da arte do tópico leis da natureza. Apresentam-se as teorias contemporâneas mais relevantes sobre o assunto, nomeadamente, teoria naïf da regularidade, teoria dos melhores sistemas, teoria da necessidade nómica, teoria da necessidade metafísica, teorias anti-reducionistas e teorias anti-realistas.

 

Session 9 19 April 2013

Fictionally Creating Fictional Characters

Fiora Salis (Lancog Group, University of Lisbon)

 

Abstract: Upholders of fictional creationism claim that fictional characters are abstract entities created by the author of fiction through the activity of story telling. They recognize that story telling involves pretense and imagination, yet they claim that by pretending to refer to a fictional individual the author genuinely brings something into existence. I distinguish two kinds of creation, genuine creation and fictional creation. Genuine creation is the process of causing something to exist or bringing something into existence. Fictional creation (I claim) is the author’s origination, performed in story telling, of a practice of thinking and talking about the same thing, even though there is not such a thing. I argue that upholders of fictional creationism have not been able to offer any adequate account of the genuine creation of fictional characters. Alternatively, I offer an account of the fictional creation of fictional characters coherent with fictional irrealism.

 

Session 8 12 April 2013

Verdade, Auto-Referência e o Fantasma de Tarski

Ricardo Santos (Universidade de Évora e LanCog Group)

 

Resumo: O teorema de Tarski diz que a propriedade de ser uma verdade aritmética não pode ser definida na linguagem da aritmética; a sua generalização diz-nos que nenhuma linguagem (com um mínimo de capacidade expressiva) pode conter o seu próprio predicado de verdade. Tarski concluiu daí que a noção intuitiva de verdade é inconsistente e que, para fins científicos, devemos substituí-la por uma hierarquia infinitamente ascendente de noções, cada uma das quais é aplicável no máximo àquela que a antecede. «Outline of a Theory of Truth» (1975), de Saul Kripke, tem sido a inspiração para a maioria dos que resistem a esta conclusão. Kripke descreveu um tipo especial de modelo – um modelo parcial de ponto fixo –, que serviria para interpretar de modo consistente uma linguagem com capacidade de auto-referência e com o seu próprio predicado de verdade.

As dificuldades começam quando tentamos avaliar os modelos de Kripke e dizer aquilo que eles pretendem mostrar. Os modelos reservam um tratamento especial para as frases paradoxais como «Esta frase não é verdadeira», na medida em que elas não caem na extensão do predicado de verdade, nem na sua anti-extensão. Ora, se a frase mentirosa não cai na extensão do predicado de verdade é porque, à luz do modelo, ela não é verdadeira. Mas isso é precisamente o que a frase mentirosa diz de si mesma. Então ela é verdadeira! E nós, ao reconhecermos e expressarmos este facto, estamos a usar um predicado de verdade de um nível superior ao da própria linguagem-objecto. Ou, como diz Kripke, «o fantasma da hierarquia de Tarski ainda está entre nós».

Analisando este problema, não apenas do ponto de vista semântico, mas também do ponto de vista da teoria da demonstração, defendo que nenhum exorcismo será possível no quadro da lógica clássica.

 

Session 7 27 March 2013

Uma defesa do Nominalismo de Avestruz

Guido Imaguire (Universidade Federal do Rio de Janeiro)

 

Resumo: Armstrong introduziu a expressão “nominalismo de avestruz” para caracterizar o tipo de nominalismo defendido por Quine. Na minha palestra, defenderei tal posição. Em primeiro lugar, discutirei as diferentes formulações do Problema dos Universais. Depois, compararei as estratégias de solução viatruthmakers e via comprometimento ontológico quantificacional. Finalmente, apresentarei a estratégia de solução do avestruz como a mais adequada solução.

 

Session 6 15 March 2013

Numbers and Everything

Gonçalo Santos (LanCog Group, UL)

 

Abstract: I begin by drawing a parallel between the intuitionistic understanding of quantification over all natural numbers and the generality relativist understanding of quantification over absolutely everything. I then argue that adoption of an intuitionistic reading of relativism not only provides an immediate reply to the absolutist’s charge of incoherence but it also throws a new light on the debates surrounding absolute generality.

 

Session 5 1 March 2013

Logic is Metaphysics

Daniel Durante (UFRN and LanCog Group, UL)

 

Abstract: Analyzing the position of two philosophers whose views are recognizably divergent, W. O. Quine and M. Dummett, we intend to support a striking point of agreement between them: the idea that our logical principles constitute our principles about what there is, and therefore, that logic is metaphysics.

 

Session 4 22nd February 2013

Uma Semântica Simples para Existenciais Negativas

João Branquinho (LanCog Group, Universidade de Lisboa

 

Resumo: É proposta uma semântica simples para um fragmento importante de predicações singulares de inexistência, frases usualmente tidas como semanticamente problemáticas. O tratamento adoptado depende de duas suposições substantivas de partida: (a) a suposição de que as frases em questão são, do ponto de vista da sua forma lógica, aquilo que parecem ser; (b) a suposição de que o predicado de existência que aí ocorre é um predicado lógico, universal. E depende ainda, mais crucialmente, de uma tese semântica algo controversa acerca da referência singular: a tese de que nomes próprios e outros termos singulares são designadores, não apenas rígidos, mas obstinadamente rígidos, dos objectos que de facto designam (Kaplan). Isto significa o seguinte: uma vez atribuído a um desses termos um objecto como sendo o referente do termo relativamente a um contexto de uso, o termo designará esse objecto com respeito a qualquer estado possível do mundo ou ocasião. Por conseguinte, tal objecto será o objecto referido pelo termo mesmo em relação a estados do mundo ou ocasiões nos quais o objecto em questão não exista. Se isto for correcto, parece haver um sentido no qual a existência não é necessária para a referência, no qual nos podemos referir àquilo que não existe. No entanto, daí não se segue, ou pelo menos não queremos que daí se siga, que há coisas que não existem.

 

Session 3 14th December 2012

Counterfactual Abduction and the Inference to the Best Explanation

Moritz Schulz (Logos Group, University of Barcelona)

 

Abstract: Counterfactuals give rise to a kind of inference (counterfactual abduction) strikingly similar to what is usually called the inference to the best explanation. On the other hand, counterfactuals seem to play a major role in inferences to the best explanation. This suggests that the two kinds of inferences could be accounted for in a unified way. I will argue that both types of inferences can be seen as a certain kind of exclusion argument which starts with a simple disjunction of hypotheses (in the case of counterfactual abduction) or with a disjunction of potential explanations (in the case of the inference to the best explanation) and then proceeds in counterfactual terms. As a result, it will turn out that both types of abduction owe their evidential import to the availability of a corresponding deductive argument. In the form of a slogan: abduction is just a special kind of deduction.

 

Session 2 30th November 2012

Variables and Attitudes

Bryan Pickel (Logos Group, University of Barcelona)

 

Abstract: Renewed interest in variables suggests that they have both an assignment unsaturated and an assignment saturated semantic value, which it contributes to the semantic processing sentences that contain it. I use this dual role of the semantics of variables to develop a new Fregean response to the argument from quantifying in to attitude ascriptions. I take as my point of departure Cumming’s (2008) view that an attitude ascription relates the subject of an attitude to the assignment-unsaturated semantic value of an open sentence. I argue that this approach fails. I propose an alternative, according to which belief is a relation to both the assignment-saturated and the assignment-unsaturated semantic value of an open sentence. This approach reverses standard assumptions concerning the relation between quantification and substitution.

 

Session 1 26th October 2012

Metaphysical Knowledge

E.J. Lowe (Durham University)

 

Abstract: My topic in this paper is metaphysical knowledge, by which I mean knowledge of metaphysical truths. And my principal questions are whether, and if so how, such knowledge is attainable by creatures like ourselves. I shall argue that we can and do possess metaphysical knowledge. But, of course, how controversial this claim is deemed to be will depend on what one takes to be distinctive of metaphysical truths. Consequently, I must first offer some account of what I take to be the nature of metaphysics as an intellectual discipline. It will soon be seen that on my account of the nature of metaphysics, the claim that we can and do possess metaphysical knowledge is indeed a controversial one and consequently one whose defence may prove interesting. But in offering this account and defending this claim, I have a deeper motive. This is to promote a certain conception of the methodology of metaphysics which is regrettably still very much in abeyance, largely on account of the dominance of first epistemology and then the philosophy of language in the western philosophical tradition of the last three hundred years.The slogan for my preferred conception of metaphysical method might well be this: metaphysics must be done directly. What I am opposing is the view — so widespread that it often goes unspoken — that metaphysics, to the extent that it can be done at all, has to be done through the medium of some other branch of philosophy, such as epistemology, logic, philosophical semantics or the philosophy of mind. What is particularly absurd about this view is that each of these branches of philosophy has, inevitably, certain distinctively metaphysical commitments which cannot possibly be warranted by doing metaphysics in the way that the view recommends. All that sustains the view in the face of this absurdity, as far as I can see, is the unspoken conviction of so many philosophers that metaphysics cannot be done, as I put it, ‘directly’. I think we owe this pernicious conviction in large measure to the ‘modernist’ legacy of Descartes, Hume, and Kant — great philosophers all of them, but all philosophers whose work contributed to the demotion of metaphysics from its central role in philosophy. It has been encouraging to see evidence of a revival in the fortunes of metaphysics in recent years, but contemporary metaphysics is still a tender plant that needs much nurturing and one that is constantly in danger of reverting to the degenerate type propagated by the modernist legacy.