Guido Imaguire

Federal University of Rio de Janeiro

A Semantic Criterion for Existential Import

19 December 2017, 16:00

Faculdade de Letras de Lisboa

Room B1

Abstract: In his book Logic and How It Gets That Way, Jacquette (2010) presents ‘the formalization paradox’ which emerges from the attempt to formalize a sentence like ‘Some monkey devours every craisin’, where craisins are imaginary non-existent fruits. From this paradox Jacquette concludes the expressive inadequacy of classical predicate quantificational logic. In this paper I analyze the three assumptions made in the emergence of the paradox, viz.: (i) colloquial expressions of the same logical form can and should be formally symbolized by applying the same symbolization schema; (ii) ‘Some monkey devours every raisin’ is correctly translated as ∃x (Mx ∧ ∀y (Ry ® Dxy)); (iii) uninstantiated predicates can legitimately enter into (meaningful, true or false) predicate-quantificational symbolizations. I fully accept (iii), but reject both (i) and (ii).  I argue, firstly, that (i) has at first glance two possible interpretations, one trivial and one false. So, I try to establish a third and more reasonable interpretation. Based on this interpretation I argue that ∃x (Mx ∧ ∀y (Ry ® Dxy)) is not the adequate formalization of ‘Some monkey devours every raisin’. My basic claim is based on a generalization of Russell’s theory of descriptions: just as most sentences of natural language which contain definite descriptions are viewed as entailing existential force which must be made explicit in formalization, so do we also consider many, although not all, sentences which contain general terms. A criterion will be presented and defended for deciding in each possible case if a sentence entails existential force.

Guido Imaguire

Federal University of Rio de Janeiro

Is Ostrich Nominalism a Dismissive Solution
to the Problem of Universals?

15 December 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Ostrich Nominalism is often described as a dismissive solution to the problem of universals. This is curious because there is no agreement about what exactly is the core of this problem, and which is its adequate formulation. In this paper I will present five different formulations and argue that Ostrich Nominalism is not dismissive at all. In fact, I will propose a positive and substantial answer to each one of the formulations of the problem. However, in order to solve predicaments of the original formulation of Ostrich Nominalism it will be important to appeal to the notion of ontological grounding and its logic.

Luís Estevinha Rodrigues

Federal University of Ceará

Mixed Epistemology, Methodological Naturalism, Gettierization and Explanatory Blindness

24 November 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Henderson & Horgan (2011) defended a middle ground epistemology with three main ingredients: low-grade apriorism, transglobal reliabilism and objective epistemic justification. In this talk I evaluate the bulk of this proposal and raise some objections concerning the scope of its naturalized chunk.

Filipe Martone

University of Campinas / FAPESP

Against Sentential and Propositional Priority in Metasemantics

17 November 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: In virtue of what do our words have meaning? It is nearly a truism that words have meaning because they are connected with human actions: we endow them with significance in virtue of using them to engage with the world. Sentence Priority is the thesis that the fundamental language-world engagement occurs at the level of whole sentences. It follows that sentences, not words, are the fundamental bearers of meaning. The motivation behind Sentence Priority is what I call Propositional Priority, the idea that propositional speech acts (things like asserting and commanding) are the most fundamental linguistic actions out of which meaning emerges. In this talk I argue that those theses cannot be right. I show that, if we accept Propositional Priority, we must accept Sentence Priority. However, Sentence Priority leads to the indeterminacy of word meaning, and this makes it impossible to explain how unused sentences have the meanings that they do. In short, Propositional and Sentence Priority are incompatible with compositionality, or so I claim. I argue that there must be at least some fundamental language-world connections at the subsentential level that explain how word meaning can directly emerge. I conclude by sketching a broadly Russellian account.

Massimiliano Carrara

University of Padua

Denial: a Logic, a Paradox and a Dilemma

10 November 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: How glut-theorists may express disagreement with the assertion of A if Boolean negation cannot be expressed in their language? A glut-theorist’s answer is by denying or rejecting A: To make up for the lack of exclusive negation, a glut-theorist like Priest introduces the notion of denial or rejection of a sentence, understood as a speech act, as clearly distinguished from the acceptance of the negation of A. I argue that the proposal meets some difficulties: the reason is that if the exclusivity of negation is the key to solving the semantic paradoxes, the exclusivity of denial/rejection land us back in paradox. I sketch a bilateral logic of exclusive denial for glut theorists – an extension of the Logic of Paradox (LP) and I observe that exclusive deniability – a key semantic notion of the logic – is not expressible in a dialetheist’s language. I conclude that glut theorists are faced with a dilemma: either denial can serve as means to express disagreement, but the notion of exclusive deniability is not expressible in the glut theorist’s language, or deniability is expressible, but denial may no longer serve as a means to express disagreement.

Bogdan Dicher

LANCOG Universidade de Lisboa

The Original Sin of Proof-Theoretic Semantics
(joint work with Francesco Paoli)

3 November 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Logical inferentialists hold that the meaning of the logical constants is determined by the rules of inference which govern their behaviour in proofs. In the inferentialist tradition, one usually identifies the derivability relation of a logic with the logic’s (internal) consequence relation. This leads to departures from the orthodox Tarskian view according to which a consequence relation is reflexive, monotonic, and transitive. Our aim is to show that the inferentialist account of the meaning of the logical constants can keep very close to the Tarskian paradigm. Using the Blok-Jonsson theory of abstract consequence relations, we show how meanings can be seen to be determined inferentialistically within the bounds of a reflexive, monotonic and transitive consequence relation.

Juhani Yli-Vakkuri

Bielefeld University

Modals and Conditionals are Ambiguous

27 October 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Following Angelika Kratzer’s classic work on modals and conditionals, the consensus in natural language semantics is that modals and conditionals (which are often thought to be a kind of modal) are indexical – in the sense that their contents depend on context – but not ambiguous. I argue that the consensus is mistaken: modals and conditionals are both indexical and ambiguous. That the difference between objective (or circumstantial) and epistemic interpretations of these expressions is not a matter of indexicality can be seen by studying the ways in which they interact with other indexicals. I reconstruct the view that modals and conditionals are only indexical using standard two-dimensional semantics for indexicals, and I show that it cannot handle the modal/indexical interaction. I then give an alternative (three-dimensional) semantics that treats modals and indexicals on their objective and epistemic readings as pairs of (indexical) homonyms, and I show that it can handle the interaction.

Catarina Dutilh Novaes

University of Groningen

The Beauty(?) of Mathematical Proofs

20 October 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Mathematicians often use aesthetic vocabulary to describe mathematical proofs: they can be beautiful, elegant, ugly, etc. In recent years, philosophers of mathematics have begun to ask themselves what these descriptions in fact mean: should we take them literally, as tracking truly aesthetic properties of mathematical proofs, or are these terms being used as proxy for non-aesthetic properties? Starting from the (largely dialogical) idea that one of the main functions of mathematical proofs is to explain and convince, I argue that most of the properties typically associated with beautiful proofs are ultimately epistemic properties. There is however an ‘aesthetic’ residue that is not to be immediately reduced to the epistemic import of proofs, namely the surprising effect that a proof may have. I argue that this aspect is rather to be understood as eliciting an affective response in the proof’s recipient, which in turn plays an important role in a proof’s persuasive effect.

Catarina Dutilh Novaes

University of Groningen

The Social Epistemology of Argumentation

16 October 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: Humans are famously a highly social species, and without collaboration with conspecifics a human being stands no chance to survive. At the same time, we compete with one another for resources at multiple levels. This combination of interdependence and competition means that exchange of information and of epistemic resources more generally among humans becomes a complex affair, involving both trust and vigilance. In my talk, I discuss the role of argumentation in the circulation and production of epistemic resources, relying on insights from social exchange theory, social epistemology, and argumentation theory.

João Pinheiro

Centro de Filosofia das Ciências da Universidade de Lisboa

The True-Fit Thesis and its Prime Corollary

13 October 2017, 16:00

Faculdade de Letras de Lisboa

Sala Mattos Romão (Departamento de Filosofia)

Abstract: According to interactivism, autonomous systems are those that maintain a non-stationary stability outside of thermodynamic equilibrium in virtue of interactions with their environment, and normativity emerges as a measure of the systems’ ability to preserve their autonomy, such that only those interactions that maintain autonomy are said to be functional. Interactivists think that this constitutes the basic framework in which one can state a minimalist theory of representation. Because the conditions under which interactions are deemed functional are in the future of the interaction once initiated, functional interactions are those that rightfully anticipate the conditions under which autonomy is maintained. In this talk I will offer a formulation and defence of a complement to this theory which I have called the True-Fit Thesis, one that reads as follows: a true-fit is an internal and extrinsic relation between true contents and the truth conditions qua success conditions of these contents bearers’ interactions. From TFT, I will then derive a corollary called Milvian Bridge (after Griffiths & Wilkins 2014), of which a possible reading is that there is positive natural selection only for truth-tropic cognitive mechanisms in virtue of their ability to preserve biosystems’ autonomy.