This paper aims to clarify the connection between the logic of temporal distinctions and the temporal features of propositions. Contra Prior, it argues that the adoption of tense operators does not commit one to the view that propositions can change their truth value over time.

McTaggart assumed (1) that propositions cannot change in truth value and (2) if (a) there is real change, then (b) events must acquire the absolute property of being present and then lose this property. He held that {1,2b} is an inconsistent set and thus inferred 2a--that there is no real change. The B theory rejects 2 and the A theory rejects 1. I accept 1, 2, 2a, and consequently, 2b, and argue that this is consistent. There is an absolute (...) property of presentness, but we can never predicate this property without producing an assertion in which that property is "chronologized." If at , we attribute presentness, we thereby attribute presentness-at-. We can grasp the existence of an absolute property which we are unable to attribute absolutely. (shrink)

Adversus Mathematicos x is the second book dedicated by Sextus to the discussion of the physical doctrines put forward by dogmatic philosophers. An extensive section deals with Diodorus Cronus' arguments concerning movement.

Adversus Mathematicos x is the second book dedicated by Sextus to the discussion of the physical doctrines put forward by dogmatic philosophers. An extensive section deals with Diodorus Cronus' arguments concerning movement.

This study shows that the Turkish expression _hani_ exhibits interesting properties for the study of the semantics and pragmatics interface, because, on the one hand, its function is merely pragmatic, but on the other hand, it is subject to the truth-conditional effect of other constituents at LF. This notwithstanding, studies on this expression are remarkably scarce. The only attempts to describe its properties are Erguvanlı-Taylan (Studies on Turkish and Turkic languages; proceedings of the ninth international conference on Turkish linguistics, 133–143, (...) 2000 ), Akar et al. (Discourse meaning, 57–78, 2020 ), and Akar and Öztürk (Information-structural perspectives on discourse particles, 251–276, 2020 ). In the present study, we introduce the first formal semantic and pragmatic treatment of clauses containing _hani_. Unlike previous accounts, we claim that _hani_ can have one of the following two major pragmatic functions: making salient a proposition in the Common Ground or challenging one in a past Common Ground, therefore requiring a Common Ground revision. Despite its variety of occurrences, we argue that _hani_ has a uniform interpretation and provide a compositional analysis of the different construals that it is associated with. Furthermore, we show that a formally explicit and accurate characterization of _hani_ clauses requires operating on indexical parameters, in particular the context time. Therefore, if our proposal is on the right track, _hani_ clauses may provide indirect empirical evidence in favour of the existence of “monstrous” phenomena, adding to the accumulating cross-linguistic evidence in this domain (see Schlenker in Linguistics and Philosophy 26(1):29–120, 2003 and much work since then). The definition of monsters is intended as in Kaplan (Themes from Kaplan, 481–563, 1989 ). (shrink)

This work aims to make tense logic a more robust tool for ontologists, philosophers, knowledge engineers and programmers by outlining a fusion of tense logic and ontology of time. In order to make tense logic better understandable, the central formal primitives of standard tense logic are derived as theorems from an informal and intuitive ontology of time. In order to make formulation of temporal propositions easier, temporal operators that were introduced by Georg Henrik von Wright are developed, and mapped (...) to the ontology of time. (shrink)

Recent attempts to resolve the truthmaker objection to presentism employ a fundamentally tensed account of the relationship between truth and being. On this view, the truth of a proposition concerning the past supervenes on how things are, in the present, along with how things were, in the past. This tensed approach to truthmaking arises in response to pressure placed on presentists to abandon the standard response to the truthmaker objection, whereby one invokes presently existing entities as the supervenience (...) base for the truth of past-directed propositions. In this paper, I argue that a fundamentally tensed approach to truthmaking is implausible because it requires the existence of cross-temporal supervenience relations, which are anathema to presentism. (shrink)

Non-bivalent semantics of the future tense assert that propositions regarding future contingents are neither true nor false. One of the most relevant non-bivalent semantics is supervaluationism :264–281, 1970; Thomason, in: Gabbay, Guenthner Handbook of philosophical logic, Springer, Berlin, 1984), which preserves important logical principles. Recently, non-bivalent semantics are under attack from some pragmatics arguments: these semantics would be incompatible with our practices of asserting future contingents and with the probability we ascribe to such assertions :251–271, 2014; Cariani and Santorio (...) in Mind 127:129–165, 2018). The aim of this paper is to defend supervaluationism against this kind of criticism. We argue that, if probability is interpreted as the subjective belief in a proposition and if a semantic contextualism is adopted, supervaluationism makes correct predictions concerning the norms that govern our practices of asserting future contingents. Obviously, other arguments can be proposed against supervaluationism, but they must be of a different kind, such as metaphysical arguments. (shrink)

Simple partial logic (=SPL) is, broadly speaking, an extensional logic which allows for the truth-value gap. First I give a system of propositional SPL by partializing classical logic, as well as extending it with several non-classical truth-functional operators. Second I show a way based on SPL to construct a system of tensed ontology, by representing tensed statements as two kinds of necessary statements in a linear model that consists of the present and future worlds. Finally I compare that (...) way with other two ways based on Łukasiewicz’s three-valued logic and branching temporal logic. (shrink)

The B-theory of time holds that McTaggart’s A-series of past, present, and future is reducible to the B-series of events running from earlier to later. According to the date-theory—originally put forth by J.J.C. Smart and later endorsed by by D.H. Mellor—the truth conditions of tensed or Asentence-tokens can be given in terms of tenseless or B-sentences and, therefore, A-sentence-tokens do not ascribe any A-determinations of pastness, presentness, or futurity. However, as Nathan Oaklander has argued, the date-theory does not provide (...) an adequate analysis of the ontological truth conditions of irreducible A-propositions. I show that the co-reporting theory—which holds that for every A-sentence-token there is a B-sentence that differs in sense but reports the same event or state of affairs—escapes the objections Oaklander has addressed against the date-theory. (shrink)

In recent years combinations of tense and modality have moved intothe focus of logical research. From a philosophical point of view, logical systems combining tense and modality are of interest because these logics have a wide field of application in original philosophical issues, for example in the theory of causation, of action, etc. But until now only methods yielding completeness results for propositional languages have been developed. In view of philosophical applications, analogous results with respect to languages of predicate logic (...) are desirable, and in this paper I present two such results. The main developments in this area can be split into two directions, differing in the question whether the ordering of time is world-independent or not. Semantically, this difference appears in the discussion whether T x W-frames or Kamp-frames (resp. Ockham-frames) provide a suitable semantics for combinations of tense and modality. Here, two calculi are presented, the first adequate with respect to Kamp-semantics, the second to T x Wsemantics. (Both calculi contain an appropriate version of Gabbay's irreflexivity rule.) Furthermore, the proposed constructions of canonical frames simplify some of those which have hitherto been discussed. (shrink)

I defend the A Theory of Time that there are tensed (and other indexical) facts, e.g., about what has happened, as well as tenseless facts, e.g., about what happened in the nineteenth century. I reject arguments of McTaggart and Grunbaum, but concentrate on Mellor’s argument that tenseless truth-conditions can be given for the truth of every tensed sentence. My rebuttal of this argument depends on a distinction between the ’proposition’ and the ’statement’ expressed by a sentence. Statements have (...) changeless truth-value, while propositions may change truth-value; but there is more to be known than knowledge of true statements can capture. (shrink)

We consider a formal language whose logical syntax involves both modal and tense propositional operators, as well as sortal quantifiers, sortal identities and (second order) quantifiers over sortals. We construct an intensional semantics for the language and characterize a formal logical system which we prove to be sound and complete with respect to the semantics. Conceptualism is the philosophical background of the semantic system.

Prior has conjectured that the tense-logical system Gli obtained by adding to a complete basis for the classical propositional calculus the primitive symbolG, the definitionsDf. F:Fα=NGNαDf. L:Lα=KαGα,and the postulatesis complete for the logic of linear, infinite, transitive, discrete future time. In this paper it is demonstrated that that conjecture is correct and it is shown that Gli has the finite model property: see [4]. The techniques used are in part suggested by those used in Bull [2] and [3]:Gli can be (...) shown to be complete for the logic of linear, infinite, transitive, discrete future time in the sense that every formula of Gli which is true of such time can be proved as a theorem of Gli. For this purpose the notion of truth needs to be formalized. This formalization is effected by the construction of a model for linear, infinite, transitive, discrete future time. (shrink)

Jeffrey King has recently argued: (i) that the semantic value of a sentence at a context is (or determines) a function from possible worlds to truth values, and (ii) that this undermines Jason Stanley's argument against the rigidity thesis, the claim that no rigid term has the same content as a non-rigid term. I show that King's main argument for (i) fails, and that Stanley's argument is consistent with the claim that the semantic value of a sentence at a context (...) is (or determines) a function from worlds to truth values. (shrink)

Tense logics formulated in the bimodal propositional language are investigated with respect to Kripke-completeness (completeness) and decidability. It is proved that all minimal tense extensions of modal logics of finite width (in the sense of K. Kine) as well as all minimal tense extensions of cofinal subframe logics (in the sense of M. Zakharyaschev) are complete. The decidability of all finitely axiomatizable minimal tense extensions of cofinal subframe logics is shown. A number of variations and extensions of these results are (...) also presented. (shrink)

Two of the main debates in philosophy of language concerning time and tense are the debate about the semantics of the tenses in the English language and the debate over whether propositions can be transiently true or false as opposed to always being eternally true or false. The latter quarrel is also known as the "temporalism–eternalism debate." Given standard semantics, the two debates are not logically independent, as we will see. Those who believe propositions are eternally true or (...) false needn’t treat the tenses as operators. Their opponents, on the other hand, appear to be committed to an operator theory of the tenses, given a standard semantic framework. In this chapter I will focus primarily on these two debates. (shrink)

The author's motivation for constructing the calculi of this paper\nis so that time and tense can be "discussed together in the same\nlanguage" (p. 282). Two types of enriched propositional caluli for\ntense logic are considered, both containing ordinary propositional\nvariables for which any proposition may be substituted. One type\nalso contains "clock-propositional" variables, a,b,c, etc., for\nwhich only clock-propositional variables may be substituted and that\ncorrespond to instants or moments in the semantics. The other type\nalso contains "history-propositional" variables, u,v,w, etc., for\nwhich only history-propositional variables may (...) be substituted and\nthat correspond to maximally linearly ordered subsets of instants.\nThis second type is for tense logics in which time is not linear\nand where at any moment there may exist alternative future courses\nof events. Quantifiers are included in both types but only for clock-\nand history-propositional variables. However, these quantifiers are\ngiven an essentially substitutional interpretation. In addition,\nbesides each clock-propositional variable being true at exactly one\ninstant, the semantics requires that for each instant there be at\nleast one clock-propositional variable true at that instant, which\nin effect amounts to having each instant of the model "denoted" in\nthe formalism by some clock-propositional variable. Thus it is not\nsurprising that quantification over clock-propositional variables\nturns out to have a "well behaved first-order semantics" (p. 284).\n{One axiom relating history- with clock-propositions seems to need\nrevision: CKTauTbuAUabUba. Since the clock-propositional variables\nmight be true at the same instant the consequent should include an\nalternative, namely, LCab.} Besides the standard truth-functional\nand tense operators G,H,F,P, the author includes L for "it is\nalways the case that". The model-theoretic earlier-than relation\nordering instants and the semantic truth-at (an instant) relation\nare formalized by Uab and Taα (for a wff α) which\nare defined respectively as LCbPa (whenever the clock-proposition\nb is the case the clock-proposition a was the case) and LCaα\n(α is the case whenever the clock-proposition a is the case).\nBecause the future tense operators are definable in terms of U\nand T and the latter are definable in terms of L and P, the\ndual of H, the author notes that his completeness proofs can be\nrestricted to L and H as primitive and with the future tense\noperators used for other interpretations, especially Prior, A.'s\nindeterminist "it will be the case that", where time is not linear.\nThe author concludes with some rather technical observations showing\nthat "in ordinary tense logics the instants are nonstandard elements\nof the models. This provides", according to the author, "a semantic\npressure to build the instants into tense logic, so that they will\nappear as standard elements in the models" (p. 283). (shrink)

Ewald considered tense operators G, H, F and P on intuitionistic propositional calculus and constructed an intuitionistic tense logic system called IKt. In 2014, Figallo and Pelaitay introduced the variety IKt of IKt-algebras and proved that the IKt system has IKt-algebras as algebraic counterpart. In this paper, we introduce and study the variety of tense Nelson algebras. First, we give some examples and we prove some properties. Next, we associate an IKt-algebra to each tense Nelson algebras. This result allowed us (...) to determine the congruence of the tense Nelson algebras and also to characterize the subdirectly irreducible tense Nelson algebras and particularly the simple tense Nelson algebras. Finally, we prove that there exists an equivalence between the category of IKt-algebras and the category of tense centered Nelson algebras. (shrink)

Intuitionistic propositional logic with Galois negations ( \(\mathsf {IGN}\) ) is introduced. Heyting algebras with Galois negations are obtained from Heyting algebras by adding the Galois pair \((\lnot,{\sim })\) and dual Galois pair \((\dot{\lnot },\dot{\sim })\) of negations. Discrete duality between GN-frames and algebras as well as the relational semantics for \(\mathsf {IGN}\) are developed. A Hilbert-style axiomatic system \(\mathsf {HN}\) is given for \(\mathsf {IGN}\), and Galois negation logics are defined as extensions of \(\mathsf {IGN}\). We give the bi-tense (...) logic \(\mathsf {S4N}_t\) which is obtained from the minimal tense extension of the modal logic \(\mathsf {S4}\) by adding tense operators. We give a new extended Gödel translation \(\tau \) and prove that \(\mathsf {IGN}\) is embedded into \(\mathsf {S4N}_t\) by \(\tau \). Moreover, every Kripke-complete Galois negation logic _L_ is embedded into its tense companion \(\tau (L)\). (shrink)

Tense logics formulated in the bimodal propositional language are investigated with respect to Kripke-completeness and decidability. It is proved that all minimal tense extensions of modal logics of finite width as well as all minimal tense extensions of cofinal subframe logics are complete. The decidability of all finitely axiomatizable minimal tense extensions of cofinal subframe logics is shown. A number of variations and extensions of these results are also presented.

According to James McCawley (1981) and Richard Larson and Gabriel Segal (1995), the following sentence is three-ways ambiguous: -/- Harry wants to be the mayor of Kenai. -/- According to them also, the three-way ambiguity cannot be accommodated on the Russellian view that definite descriptions are quantified noun phrases. In order to capture the three-way ambiguity of the sentence, these authors propose that definite descriptions must be ambiguous: sometimes they are predicate expressions; sometimes they are Russellian quantified noun phrases. After (...) explaining why the McCawley-Larson-Segal solution contains an obvious flaw, I discuss how an effort to correct the flaw brings to light certain puzzles about the individuation of desires, about quantifying in, and about the disambiguation of desire ascriptions. (shrink)

Cappelen and Hawthorne’s Relativism and Monadic Truth (2009) offers an extended defense of a thesis they call simplicity, which, in brief, holds that propositions are true or false simpliciter. Propositions are cast in their traditional roles as the contents of assertions, and as the semantic values of declarative sentences in contexts. Simplicity stands in sharp contrast to forms of relativism including, for instance, a form that hold that our claims are true or false only relative to a judge. (...) This applies especially to claims of taste, which come out true or false only relative to the judge who finds things tasty (e.g. Glanzberg 2007, Lasersohn 2005). But simplicity also rejects the more widespread temporalist view that propositions are true or false only relative to a time, and it rejects the even more widely held view that propositions are true or false only relative to a world. One reason that has been advanced for temporalism, e.g. by Kaplan (1989), is that our languages seem to contain non-trivial temporal operators. Hence, the argument goes, the semantic values of sentences need to be temporally neutral, i.e. vary for truth or falsehood with time. The same goes for possible worlds and modal operators. Hence, Kaplan and many others think of the semantic values of sentences as sets of world-time pairs. It has been tempting to apply this sort of argument much more widely, to see the semantic values of sentences as varying not just with world and time, but perhaps with location and other parameters as well. Kaplan.. (shrink)

The tense tree method extends Jeffrey’s well-known formulation of classical propositional logic to tense logic (Jeffrey 1991).1 Tense trees combine pure tense logic with features of Prior’s U-calculi (where ‘U’ is the earlier-than relation; see Prior 1967 and the Introduction to this volume). The tree method has a number of virtues: trees are well suited to computational applications; semantically, the tree systems presented here are no less illuminating than model theory; the metatheory associated with tree formulations is often more tractable (...) than that required in a model-theoretic setting; and last but not least the tree method is ideal for pedagogical purposes. (shrink)

In this paper we argue that Prior and Reichenbach are best viewed as allies, not antagonists. We do so by combining the central insights of Prior and Reichenbach in the framework of hybrid tense logic. This overcomes a well-known defect of Reichenbach’s tense schema, namely that it gives multiple representations to sentences in the future perfect and the future-in-the-past. It also makes it easy to define an iterative schema for tense that allows for multiple points of reference, a possibility noted (...) by Prior and demanded by Comrie, and we sketch how this schema can be generalized to a shift-and-restrict pattern in which special propositional symbols act as restrictors on the range of tense operators. (shrink)

Sentences of natural languages are often said to express propositions and to have meanings . This work is about the nature of such entities and their role in an account of the truth conditions of tensed attributions of belief containing demonstratives and indexicals. ;In Chapter I, I discuss the temporal properties of propositions. Two views concerning the temporal properties of propositions--temporalism and eternalism--are characterized; eternalism is defended as the correct view. I show that the temporalist cannot (...) give adequate truth conditions for tensed attributions of belief, and, in addition, that criticisms of eternalism made by David Kaplan are unfounded. I also show that, given the truth of eternalism, Kaplan's identification of sentence meaning with character must be rejected. ;Chapter II takes, as its point of departure, Kaplan's work on demonstratives. An account of the semantical properties of demonstratives and indexicals is presented, one based upon Kaplan's account, but modified in the light of the results of Chapter I. It is then argued, on the basis of this account, that the usual truth conditions accorded to attributions of belief are incorrect: I argue that an attribution of belief is not true simply if the person to whom belief is attributed believes the proposition expressed by the sentence used to attribute belief. ;In Chapter III, two recent attempts to deal with the problems raised in Chapter II are considered: The semantics for attributions of belief suggested by Robert Stalnaker and Bas C. van Fraassen. On Stalnaker's and van Fraassen's views, in attributing belief to a person u using a sentence S, we sometimes do not attribute to u a belief in the proposition expressed by S, but in some other proposition. Both accounts are shown to be unacceptable. ;Finally, in Chapter IV, a solution to the problems raised in Chapter II is proposed. I suggest that not only the proposition expressed by a sentence S, but the meaning of S, is involved in truth conditions for attributions of belief containing S. The work concludes with a formal development of this proposal. (shrink)

This dissertation includes an introduction, five main chapters, and a conclusion. In the chapter “The Definition of Change”, I expound Aquinas’ account of change. I maintain that Aquinas’ account is meant to describe both spiritual and material changes. Hence, the hylomorphic account of change as the passage from form-less matter to enformed matter is unable to describe all changes. Contrary to Brower, I suggest that Aquinas’ favorite model involves a passage from potentiality to actuality. In addition, I state that ‘change’ (...) is identical to the second potentiality/first actuality of a process that includes three steps, a first potentiality, a second potentiality, and a second actuality. In the chapter on “Aquinas, Presentism, and Adverbialism”, I analyze the semantics of propositions that describe changing processes. I maintain that Aquinas subscribed to the view that past and future tense statements can have a truth-value. Chapter 4 is devoted to the so-called principle of plenitude, i.e. the thesis that all possibilities are realized at some point in the future. Aquinas is believed to have subscribed to the principle, whereas Aristotle’s texts are much more disputed. In this chapter, I offer a new interpretation, according to which Aristotle accepted a restricted version of the principle of plenitude, but Aquinas rejected the principle in all its formulations. In chapter 5 “Aquinas on Future Contingents”, I expound Aquinas’ theory of future contingents events. In this chapter, I make two claims. I state that Aquinas’ theory entails that future events do not exist, according to the ‘actual’ sense of existence. My second claim is about the logic of future contingents. I claim that Aquinas’ argument is logically sound, but presupposes that the so-called K-formula is not a tautology of Aquinas’ modal system. In chapter 6 I expound Aquinas’ definition of time. I maintain that Aquinas’ definition is not circular and time is distinct in both definition and in essendo from change. I conclude by stating that time has extra-mental existence. (shrink)

The last chapter examines the tense system used by ordinarily competent speakers of English to discuss past, present, and future events, actual and possible events, and various combinations of these. I present a systematic method for translating English sentences containing certain compound verb tenses and embedded tense constructions into a logical language using tense operators. Finally I show how the usual semantics for these operators reflects the truth conditions of the original English sentences. I argue, however, that a tense logical (...) semantics reflecting the use of tense in English will contain a partially ordered tense structure rather than one that is linearly ordered or branching. ;The third chapter discusses logic of 'unless'. I show that many of the previously puzzling features of this word can be understood by considering the tenses of the verbs in the sentences joined by 'unless'. In a number of cases it turns out that 'unless' should not be interpreted as a truth-functional connective at all, but is best understood as an intensional, tense connective. ;In the second chapter I discuss Quine's doctrine of eternal sentences. I take Quine's position to be that all the information important for logic and science presented in tensed English sentences can also be presented by eternal sentences which use timeless verbs and data and clock times. I argue that in so far as logic and science are concerned with an analysis of the reasons for human action, and with the explanation and prediction of specific events, eternal sentences lose indexical information that is necessary to accomplish these tasks. ;The first chapter investigates what may be called the standard view of propositions. On this view propositions are abstract objects that are timelessly true , and serve both as the meanings of sentences and as the objects of propositional attitudes. Although this view was widely held by a previous generation of logicians and is found in many textbooks today, there are serious difficulties in the view. I show that many of these difficulties stem from the claim that propositions are timelessly true . The standard view has been revised in two general ways. The first sort of revision allows propositions to be sometimes true and sometimes false. This position is consistent with the development of tense logic as one of the intensional logics. The second sort of revision replaces the notion of timeless propositions with that of eternal sentences which always have the same truth value. On this view tense logic is not worth serious philosophic attention since its basic notion, that of truth at a time, can be eliminated in favor of eternal truth. ;The first part of the project examines two major sources of criticism of tense logic: the view that logic is concerned with timeless propositions, and Quine's doctrine of eternal sentences. The second part of the project discusses several problems in logical theory that the use of tense logic can clarify or resolve, and that alternative theories are unable to present accurately, much less to elucidate. ;In the past few years there has been increasing interest in the logic of indexicals, including the temporal indexical 'now', and in the relationship between tense and modality. Although modern tense logic has reached a high level of technical sophistication, often specifically in response to this interest, many philosophers remain skeptical about the value of tense logic as a philosophic tool. This thesis addresses that skepticism and argues that it is unjustified. (shrink)

The paper has two parts: First, I describe a relatively popular thesis in the philosophy of propositional attitudes, worthy of the name ‘taking tense seriously’; and I distinguish it from a family of views in the metaphysics of time, namely, the A-theories (or what are sometimes called ‘tensed theories of time’). Once the distinction is in focus, a skeptical worry arises. Some A-theorists maintain that the difference between past, present, and future, is to be drawn in terms of what (...) exists: growing-block theorists eschew ontological commitment to future entities; presentists, to future and past entities. Others think of themselves as A-theorists but exclude no past or future things from their ontology. The metaphysical skeptic suspects that their attempt to articulate an ‘eternalist’ version of the A-theory collapses into merely ‘taking tense seriously’– a thesis that does not imply the A-theory. The second half of the paper is the search for a stable eternalist A-theory. It includes discussion of temporary intrinsics, temporal parts, and truth. (shrink)

It is a widely held view in philosophy that propositions perform a plethora of different theoretical roles. Amongst other things, they are believed to be the semantic values of sentences in contexts, the objects of attitudes, the contents of illocutionary acts, and the referents of that-clauses. This assumption is often combined with the claim that propositions have their truth-values eternally. In this paper I aim to show that these two assumptions are incompatible: propositions cannot both fulfill the (...) mentioned roles and be eternally true or false. Following Kaplan and Lewis’s Operator Argument, I argue that compositional semantic values of sentences in contexts do not correspond to eternal propositions. Thus, either we regard the non-eternal entities that in fact realize the semantic role of propositions as also fulfilling the remaining propositional roles, or we abandon the assumption that there is a unique realizer of all the roles. The Operator Argument has recently come under attack, mainly for its tense-logical assumptions. However, rejecting these assumptions is not a sufficient defense of the compatibility of the two claims, since the extensional alternative to the tense-logical framework does not allow us to universally retain eternal propositions as compositional semantic values of sentences either. (shrink)

In this work Ockham proposes a theory of simple predication, which he uses in explicating the truth conditions of progressively more complicated kinds of propositions. His discussion includes what he takes to be the correct semantic treatment of quantified propositions, past tense and future tense propositions, and modal propositions, all of which are receiving much attention from contemporary philosophers. He also illustrates the use of exponential analysis to deal with propositions that prove troublesome in both (...) semantic theory and other disciplines, such as metaphysics, physics, and theology. This type of analysis plays an essential role in his substantive philosophical and theological works, and in many cases then can hardly be understood without a prior acquaintance with this section of the Summa. An introduction by Alfred J. Freddoso clarifies and summarizes Ockham's theory, discusses certain philosophical problems which it engenders, and proposes new interpretations for parts of it. The essay will be helpful both to those interested in Ockham as a historical figure and to those interested in his substantive systematic contributions to logical theory. (shrink)

Tense logics in the bimodal propositional language are investigated with respect to the Finite Model Property. In order to prove positive results techniques from investigations of modal logics above K4 are extended to tense logic. General negative results show the limits of the transfer.

This paper starts the systematic study of inconsistency measures for propositional logics enriched with operators involving time. We use Prior’s operators for tense logic: H, G, P, and F; however, we apply different semantics to them. We define two logics. The first one, ATPL, allows formulas with the application of any of the four operators any number of times to propositional logic formulas. The semantics is given in terms of TPL structures. We then show how to measure the inconsistency of (...) a set of ATPL formulas using appropriately modified versions of standard inconsistency measures for propositional logic. Additionally, these new measures are checked for the satisfaction of various properties. We also investigate a new concept of inconsistency that cannot be defined for propositional logic. Then, ATPL is extended to CTPL by applying the propositional connectives to ATPL formulas and measuring inconsistency is extended to sets of CTPL formulas. (shrink)

Transient Truths: An Essay in the Metaphysics of Propositions provides the first book-length exposition and defense of semantic temporalism, the view that propositions are contents or semantic values that can change their truth-values across time.

In at least some cases of future directed propositional hoping, facts about the hoper become puzzling if one supposes that the object of hoping is a future tensed proposition. These facts are easily explained by the alternative suppostion that the hoper accepts a future tensed proposition but bears the hopingattitude toward a disjunctively tensed proposition. Parallel remarks apply to past directed and present directed prepositional hoping. Thus, at least some instances of hoping have as their objects disjunctively (...) tensed rather than purely tensed propositions. Propositional remembering may possibly resemblepropositional hoping in this respect. (shrink)

The aim of this paper1 is to provide a unified semantic analysis for three important readings of the Italian Imperfetto (and Presente): the PROGressive, the HABitual, and the FUTurate reading. To highlight the role of the utterance context in setting the relevant parameters of interpretation, explicit temporal adverbials are left out of the scene and prominence is given to the situations where the context provides the temporal information required to discriminate between alternative readings, by exploiting a single logical form. The (...) paper is organized as follows. After a short presentation of the data (sect. 1), in the second section I discuss some intuitive features of imperfectivity by focusing on the fact that the conclusion of an event or series of events is left open. This indeterminacy with respect to a given perspective point is formalized in the third section of the paper by resorting to a branching time model. In the third section a unitary treatment (based on the derivation of a single logical form) is proposed for the three main readings of tenses such as the Presente and the Imperfetto and for an intriguing side effect that, in some particular circumstances, makes a "perfective" reading possible. Since the context has a key role in this reconstruction of imperfectivity, the last section of the paper is devoted to the consideration of the temporal parameters to which the evaluation of an utterance is relativized. (shrink)

Consistency is one of the key concepts of logic; logicians have put a great deal of effort into proving the consistency of many logics. Understanding what causes inconsistency is also important; some logicians have developed paraconsistent logics that, unlike classical logics, allow some contradictions without making all formulas provable. Another direction of research studies inconsistency by measuring the amount of inconsistency of sets of formulas. While the initial attempt in 1978 was too ambitious in trying to do this for first-order (...) logic, this research got a substantial boost when an inconsistency measure was proposed for propositional logic in 2002. Since then, researchers in logic and artificial intelligence have made many interesting proposals and found related issues. Almost all of this work has been done for propositional logic. The purpose of this paper is to extend inconsistency measures to logics that also contain operators, such as modal operators. We use the terminology “generalized propositional logic” for such logics. We show how to extend propositional inconsistency measures to sets of formulas in any such generalized propositional logic. Examples are used to illustrate how various modal operators, including spatial and tense operators, fit into this framework. We also show that the addition of operators leads to a weak type of inconsistency. In all cases, the calculations for several inconsistency measures are given. (shrink)

In this paper, we will study Heyting algebras endowed with tense negative operators, which we call tense H-algebras and we proof that these algebras are the algebraic semantics of the Intuitionistic Propositional Logic with Galois Negations. Finally, we will develop a Priestley-style duality for tense H-algebras.