We consider a paradox involving indicative conditionals (‘ifs’) and deontic modals (‘oughts’). After considering and rejecting several standard options for resolv- ing the paradox—including rejecting various premises, positing an ambiguity or hidden contextual sensitivity, and positing a non-obvious logical form—we offer a semantics for deontic modals and indicative conditionals that resolves the paradox by making modus ponens invalid. We argue that this is a result to be welcomed on independent grounds, and we show that rejecting the general validity of modus (...) ponens is compatible with vindicating most ordinary uses of modus ponens in reasoning. (shrink)

Reconhecido centro de formação profissional em carreiras jurídicas, o IDC oferece Especialização, preparação para Exame de Ordem e Cursos de Extensão em mais de 20 áreas do Direito, aprofundando os conhecimentos de advogados e bacharéis. Possui também graduação em Filosofia, além de promover Cursos Preparatórios para Concursos em diversas áreas, obtendo excelentes resultados de aprovação graças à preocupação constante na qualificação e excelência de seu corpo docente e infra-estrutura.

An agent in a decision problem may not know the goals that should guide selection of an option. Accommodating this ignorance require methods that supplement expected utility theory.

Imperatives may be interpreted with many subvarieties of directive force, for example as orders, invitations, or pieces of advice. I argue that the range of meanings that imperatives can convey should be identified with the variety of interpretations that are possible for non-dynamic root modals (what I call ‘priority modals’), including deontic, bouletic, and teleological readings. This paper presents an analysis of the relationship between imperatives and priority modals in discourse which asserts that, just as declaratives contribute to the Common (...) Ground and thus provide information relevant to the interpretation of epistemic modals in subsequent discourse, imperatives contribute to another component of the discourse context, the addressee’s To-Do List, which serves as a contextual resource for the interpretation of priority modals. This analysis predicts that the interpretation of imperatives and modals in discourse is constrained in surprising ways; these predictions are borne out. (shrink)

The present study examined the neural substrate of two classes of quantifiers: numerical quantifiers like ” at least three” which require magnitude processing, and logical quantifiers like ” some” which can be understood using a simple form of perceptual logic. We assessed these distinct classes of quantifiers with converging observations from two sources: functional imaging data from healthy adults, and behavioral and structural data from patients with corticobasal degeneration who have acalculia. Our findings are consistent with the claim that numerical (...) quantifier comprehension depends on a lateral parietal-dorsolateral prefrontal network, but logical quantifier comprehension depends instead on a rostral medial prefrontal-posterior cingulate network. These observations emphasize the important contribution of abstract number knowledge to the meaning of numerical quantifiers in semantic memory and the potential role of a logic-based evaluation in the service of non-numerical quantifiers. (shrink)

Szymanik (2007) suggested that the distinction between first-order and higher-order quantifiers does not coincide with the computational resources required to compute the meaning of quantifiers. Cognitive difficulty of quantifier processing might be better assessed on the basis of complexity of the minimal corresponding automata. For example, both logical and numerical quantifiers are first-order. However, computational devices recognizing logical quantifiers have a fixed number of states while the number of states in automata corresponding to numerical quantifiers grows with the rank of (...) the quantifier. This observation partially explains the differences in processing between those two types of quantifiers (Troiani et al. 2009) and links them to the computational model. Taking this perspective, below, we suggest the experimental setting extending the one by McMillan et al. (2005) and Troiani et al. (2009). (shrink)

We examine the verification of simple quantifiers in natural language from a computational model perspective. We refer to previous neuropsychological investigations of the same problem and suggest extending their experimental setting. Moreover, we give some direct empirical evidence linking computational complexity predictions with cognitive reality.<br>In the empirical study we compare time needed for understanding different types of quantifiers. We show that the computational distinction between quantifiers recognized by finite-automata and push-down automata is psychologically relevant. Our research improves upon hypothesis and (...) explanatory power of recent neuroimaging studies as well as provides<br>evidence. (shrink)