Tense, aspect and temporal reference

English exhibits a rich apparatus of tense, aspect, time adverbials and other expressions that can be used to order states of affairs with respect to each other, or to locate them at a point in time with respect to the moment of speech. Ideally one would want a semantics for these expressions to demonstrate that an orderly relationship exists between any one expression and the meanings it conveys. Yet most existing linguistic and formal semantic accounts leave something to be desired in this respect, describing natural language temporal categories as being full of ambiguities and indeterminacies, apparently escaping a uniform semantic description. It will be argued that this anomaly stems from the assumption that the semantics of these expressions is directly related to the linear conception of time familiar from temporal logic or physics - an assumption which can be seen to underly most of the current work on tense and aspect. According to these theories, the cognitive work involved in the processing of temporal discourse consists of the ordering of events as points or intervals on a time line or a set of time lines. There are, however, good reasons for wondering whether this time concept really is the one that our linguistic categories are most directly related to; it will be argued that a semantics of temporally referring expressions and a theory of their use in defining the temporal relations of events require a different and more complex structure underlying the meaning representations than is commonly assumed. A semantics will be developed, based on the assumption that categories like tense, aspect, aspectual adverbials and propositions refer to a mental representation of events that is structured on other than purely temporal principles, and to which the notion of a nucleus or consequentially related sequence of preparatory process, goal event and consequent state is central. It will be argued that the identification of the correct ontology is a logical preliminary to the choice of any particular formal representation scheme, as well as being essential in the design of natural language front-ends for temporal databases. It will be shown how the ontology developed here can be implemented in a database that contains time-related information about events and that is to be queried by means of natural language utterances

A topological perspective for branching-time logics

Questa tesi è suddivisa in due parti: - nella prima parte, abbiamo descritto la *Logica Temporale* e, in particolare, alcune logiche del tempo ramificato; - nella seconda parte abbiamo analizzato da un punto di vista topologico alcune proprietà algebriche degli alberi, su cui sono basate molte semantiche per la logica temporale. L'obiettivo principale della Logica temporale è la definizione di un linguaggio formale (e di una semantica) che possa esprimere proposizioni con tempi verbali, come "Ha piovuto", "Ho dormito, in passato", "In futuro impareremo a volare". Si osserva immediatamente che il valore di verità di queste proposizioni dipende dal momento in cui sono considerate, a differenza delle proposizioni della Logica Classica. Perciò, il primo passo per una definizione di verità in questo contesto è quello di costruire una adeguata struttura matematica che rappresenti il tempo. Nei primi due capitoli, analizzeremo varie scelte sintattiche e semantiche per la Logica Temporale, e differenti assunzioni ontologiche (una su tutte, l'*Indeterminismo*) che modificheranno il modello del tempo considerato. Seguendo l'articolo *Topological Aspects of Branching-Time Semantics *(2003) di M. Sabbadin e A. Zanardo, nel terzo capitolo abbiamo preso in considerazione una semantica inusuale per la Logica Temporale, basata su una naturale struttura topologica aggiunta alla semantica Ockhamista. In particolare, lo spazio dei rami massimali (o storie) della rappresentazione ad albero del tempo diventa uno spazio topologico *non-Archimedeo*. In questo capitolo vengono analizzate in dettaglio le proprietà di questo spazio, e viene dimostrato un importante risultato di validità. Infine il quarto capitolo, che è in parte un lavoro di ricerca, contiene la "traduzione" in questo nuovo linguaggio topologico di varie proprietà algebriche degli alberi. Vengono descritte le proprietà topologiche dello spazio delle storie degli alberi lineari, degli alberi finitamente ramificati, di quelli ben fondati, e di altre classi più particolari, come gli alberi ω-cofinali e gli alberi *jointed*. Il capitolo si conclude con un'analisi degli alberi di Souslin e degli alberi speciali, strettamente collegati al noto *Problema di Souslin*

Two Perspectives on Change and Institutions

Abstract The contrast between internal and external perspectives on change, discussed within applied ontology in recent years by Galton, is linked to the difference between finite automata and their runs. The link is based on a finite approximability hypothesis, under which granularities are bounded by signatures in institutions, as defined by Goguen and Burstall. How abstract types, described internally, are realized externally as concrete particulars is complicated by differences in signatures and by competing processes with related signatures

The Invisible Thin Red Line

The aim of this paper is to argue that the adoption of an unrestricted principle of bivalence is compatible with a metaphysics that (i) denies that the future is real, (ii) adopts nomological indeterminism, and (iii) exploits a branching structure to provide a semantics for future contingent claims. To this end, we elaborate what we call Flow Fragmentalism, a view inspired by Kit Fine (2005)’s non-standard tense realism, according to which reality is divided up into maximally coherent collections of tensed facts. In this way, we show how to reconcile a genuinely A-theoretic branching-time model with the idea that there is a branch corresponding to the thin red line, that is, the branch that will turn out to be the actual future history of the world

In Defense of Irreducible Relations

At least since Russell, mainstream analytic philosophy has distinguished internal and external relations and acknowledged the existence of both. This seems in line with both the manifest and scientific images of the world. However, there is a recent deflationary trend about relations, which focuses on the truthmakers of relational statements in order to show that putative external relations are in fact internal, and that internal relations do not really exist. Lowe’s posthumous 2016 paper is a thorough presentation of this line of thought. This article critically analyzes Lowe’s arguments in that paper, and some related arguments in recent works. It finds them wanting and thus reaffirms the irreducible reality of relations

Essence and Ontology

This dissertation provides an account of essentiality that satisfies two main desiderata: (1) The account should offer an explanation as to why the following two intuitions are true: (i) It is essential to the set {Socrates} to have Socrates as a member. (ii) It is not essential to Socrates to be a member of that set. (2) The account should do justice to the sense of philosophical significance that has traditionally been attached to the notion of essence. The two intuitions mentioned in: 1) together form what I call `Fine\u27s asymmetry\u27, after Kit Fine, whose paper `Essence and Modality\u27 has persuasively undermined the traditional modal account of essentiality by pointing out: among other worries) that this account cannot plausibly accommodate both of those intuitions. The account of essentiality proposed in this dissertation offers an alternative to the modal account. It is reductive, in the sense that it provides truth-conditions for essentialist claims without in turn relying on any fundamental notions of an entity\u27s `nature\u27 or `identity\u27; nor does it rely on any concepts of metaphysical modality. Instead, it is based on a framework of sets, attributes, and states of affairs, which is introduced in chapters 2 and 3. The account itself is then developed in chapters 4 to 7. The first major step in this direction is the introduction, in chapter 4, of the concept of an individuational ontology, which results from a generalization and modification of Peter Aczel\u27s approach to the theory of non-well-founded sets. On this basis, chapter 5 introduces relativized concepts of essence and essentiality, where the relativization in question is to individuational ontologies. The question of what conditions an individuational ontology O has to satisfy in order for essences-relative-to-O to count as essences simpliciter is the topic of chapters 6 and 7. Chapter 6 sets out to develop a fairly straightforward approach, but this is quickly seen to face apparently insuperable difficulties. Chapter 7 develops a fundamentally different approach, which turns out to be more successful. In chapter 8, it is shown how the resulting account of essentiality manages to accommodate Fine\u27s asymmetry, and in the final chapter, the account is applied to an elucidation of de re modal discourse