Analytic philosophy has recently demonstrated a revived interest in metaphysical problems about possibility and necessity. Graeme Forbes here provides a careful description of the logical background of recent work in this area for those who may be unfamiliar with it, moving on to d discuss the distinction between modality de re and modality de dicto and the ontological commitments of possible worlds semantics. In addition, Forbes offers a unified theory of the essential properties of sets, organisms, artefacts, substances, and events, (...) based on the doctrine that identity facts must be intrinsically grounded, and analyzes and rejects apparent counterexamples to this doctrine. (shrink)

The Growing-Block view of time has some problems with the past. It is committed to the existence of the past, but needs to say something about the difference between the past and present. I argue that we should resist Correia and Rosenkranz’ response to Braddon-Mitchell’s argument that the Growing-Block leads to scepticism about whether we are present. I consider an approach, similar to Peter Forrest, and show it is not so counter-intuitive as Braddon-Mitchell suggests and further show that it requires (...) no ‘semantic and metaphysical gymnastics’, as Chris Heathwood has suggested. In doing these things I make the problem of the past on the Growing-Block view a problem in its history, not its present. (shrink)

Ascriptions of mental states to oneself and others give rise to many interesting logical and semantic problems. Attitude Problems presents an original account of mental state ascriptions that are made using intensional transitive verbs such as 'want', 'seek', 'imagine', and 'worship'. Forbes offers a theory of how such verbs work that draws on ideas from natural language semantics, philosophy of language, and aesthetics.

This paper is about a substitution-failure in attitude ascriptions, but not the one you think. A standard view about the semantic shape of ‘that’-clause attitude ascriptions is that they are fundamentally relational. The attitude verb expresses a binary relation whose extension, if not empty, is a collection of pairs each of which consists in an individual and a proposition, while the ‘that’-clause is a term for a proposition. One interesting problem this view faces is that, within the scope of many (...) attitude verbs, ‘that’-clauses are not interchange able with certain other terms which stand for the same propositions as the clauses are supposed to. For example, (1a) below may be true, but (1c) is probably not: (1) a. Holmes {fears/suspects} that Moriarty has returned. b. That Moriarty has returned is the proposition that Moriarty has re turned. c. Holmes {fears/suspects} the proposition that Moriarty has returned. For only the exceptionally timorous fear propositions, and, excluding contexts in which we speak of a ‘suspect premise’, only the unusually paranoid suspect them. The truth-conditional change eVected by substituting propositional descrip tion for ‘that’- clause illustrated in (1) occurs with a wide range of attitude verbs. If you understand that the window of opportunity is closing, perhaps you should act before it is too late, but if you mere-. (shrink)

In this article, we consider two independently appealing theories—the Growing-Block view and Humean Supervenience—and argue that at least one is false. The Growing-Block view is a theory about the nature of time. It says that past and present things exist, while future things do not, and the passage of time consists in new things coming into existence. Humean Supervenience is a theory about the nature of entities like laws, nomological possibility, counterfactuals, dispositions, causation, and chance. It says that none of (...) these entities are fundamental, since if they were, this would entail the existence of irreducible necessary connections between matters of fact. Instead, these entities supervene on a fundamental, non-nomological ‘Humean mosaic’ of property instances at spacetime points. We will further explain and motivate the Growing-Block view and Humean Supervenience in Sects. 2 and 3, but first, we turn to our master argument. (shrink)

Growing-Block theorists hold that past and present things are real, while future things do not yet exist. This generates a puzzle: how can Growing-Block theorists explain the fact that some sentences about the future appear to be true? Briggs and Forbes develop a modal ersatzist framework, on which the concrete actual world is associated with a branching-time structure of ersatz possible worlds. They then show how this branching structure might be used to determine the truth values of future contingents. They (...) point out three different ways of interpreting the logical connectives, which give rise to three different logics of the open future: one supervaluationist, one corresponding to Lukasiewicz's strong Kleene logic, and one intuitionist. (shrink)

This paper discusses some recent responses to Kripke’s modal objections to descriptivism about names. One response, due to Gluer-Pagin and Pagin, involves employing "actually" operators in a new way. Another, developed mainly by Chalmers, involves distinguishing the dimension of meaning modal operators affect from the dimension other operators, especially epistemic ones, affect. I argue that both these moves run into problems with "mixed" contexts involving factive verbs such as "know", "establish", "prove", etc. In mixed contexts there are both modal and (...) epistemic operators, and it seems that some contradictory examples, such as "possibly (Hesperus has a moon and someone establishes that Hesperus has no moon)", are classified as true according to these views. (shrink)

Filling the need for an accessible, carefully structured introductory text in symbolic logic, Modern Logic has many features designed to improve students' comprehension of the subject, including a proof system that is the same as the award-winning computer program MacLogic, and a special appendix that shows how to use MacLogic as a teaching aid. There are graded exercises at the end of each chapter--more than 900 in all--with selected answers at the end of the book. Unlike competing texts, Modern Logic (...) gives equal weight to semantics and proof theory and explains their relationship, and develops in detail techniques for symbolizing natural language in first-order logic. After a general introduction featuring the notion of logical form, the book offers sections on classical sentential logic, monadic predicate logic, and full first-order logic with identity. A concluding section deals with extensions of and alternatives to classical logic, including modal logic, intuitionistic logic, and fuzzy logic. For students of philosophy, mathematics, computer science, or linguistics, Modern Logic provides a thorough understanding of basic concepts and a sound basis for more advanced work. (shrink)

This paper is about the cluster of issues that orbit a well-known thesis of Quine’s, as it applies to attitude ascriptions.

In a recent article in Analysis, Graeme Hunter and William Seager (1981) attempt to rescue counterpart theory (CT) from some objections of Hazen 1979. They see these objections as arising from ‘uncritical use of the translation scheme originally proposed by Lewis’, and intend to meet them by refraining from use of that scheme. But they do not offer a new scheme; they say ‘…it is no more necessary to have one to capture the sense of modal idiom than it is (...) to capture the sense of quantificational idiom…Appeal to truth value is the single most important criterion of correct translation’ (Hunter and Seager 1981:72). Thus, where the scheme of Lewis (1968) translates a truth by a falsehood or conversely, Hunter and Seager simply produce a sentence which they claim to be a better translation, without articulating any structural principles they employ to arrive at their candidate. A friend of CT should not be happy with this procedure. Let Lm be first-order modal language and Lc be the language of counterpart theory. Sentences of Lc are intended to interpret or elucidate the meanings of Lm-sentences in the strong sense that they should be the outputs of an adequate theory of meaning, which we can formulate as a model theory, for Lm, written in Lc plus set theory. The interest of CT resides in its potential to provide an alternative approach to the model theory of modal logic, and from the clauses of any such alternative model theory we should be able to read off a translation scheme for Lm into Lc, just as we can in the standard case. If CT’s motivation is sound, which Hunter and Seager do not dispute, yet there is no translation scheme and so no counterpart-theoretic model theory, one might suspect some defect in the original language Lm. And in fact, Hunter and Seager find certain Lm-sentences multiply ambiguous with respect to Lc; but if a counterpart-theoretic model theory is possible, to say.. (shrink)

A verb is transitive iff it usually occurs with a direct object, and in such occurrences it is said to occur transitively . Thus ‘ate’ occurs transitively in ‘I ate the meat and left the vegetables’, but not in ‘I ate then left’ (perhaps it is not the same verb ‘left’ in these two examples, but it seems to be the same ‘ate’). A verb is intensional if the verb phrase (VP) it forms with its complement is anomalous in at (...) least one of three ways: (i) interchanging expressions in the complement referring to the same entity can change the truth-value of the sentence embedding the VP; (ii) the VP admits of a special “unspecific” reading if it contains a quantifier, or a certain type of quantifier; and (iii) the normal existential commitments of names and existential quantifiers in the complement are suspended even when the embedding sentence is negation-free. (shrink)

This paper is about two puzzles, or two versions of a single puzzle, which deserve to be called paradoxes, and develops some apparatus in terms of which the apparently conflicting principles which generate the puzzles can be rendered consistent. However, the apparatus itself is somewhat controversial: the puzzles are modal ones, and the resolution to be advocated requires the adoption of a counterpart theoretic semantics of essentially the kind proposed by David Lewis, which in turn requires qualified rejection of certain (...) modal theses about identity which are valid in S5. (shrink)

A New Route to the Necessity of Origin’, Guy Rohrbaugh and Louis deRossett argue for the Necessity of Origin in a way that they believe avoids use of any kind of transworld constitutional sufficiency principle. In this discussion, we respond that either their arguments do imply a sufficiency principle, or else they entirely fail to establish the Necessity of Origin.

The delicate point in the formalistic position is to explain how the non-intuitionistic classical mathematics is significant, after having initially agreed with the intuitionists that its theorems lack a real meaning in terms of which they are true (S. C. Kleene, 1952).

The article considers whether arguments involving sentences that make cross-world comparisons ("I could have been taller than I actually am") are better handled by counterpart theory than by standard modal semantics. The author describes a modal object-language in which such statements may be symbolized and gives both a Kripkean and a counterpart-theoretic semantics for it.

[Graeme Forbes] In I, I summarize the semantics for the relational/notional distinction for intensional transitives developed in Forbes. In II-V I pursue issues about logical consequence which were either unsatisfactorily dealt with in that paper or, more often, not raised at all. I argue that weakening inferences, such as 'Perseus seeks a mortal gorgon, therefore Perseus seeks a gorgon', are valid, but that disjunction inferences, such as 'Perseus seeks a mortal gorgon, therefore Perseus seeks a mortal gorgon or an immortal (...) gorgon', are invalid. Since 'a gorgon' and 'a mortal gorgon or an immortal gorgon' are extensionally and intensionally the same quantifier, it is not completely trivial to arrange the semantics of intensional transitives so that this classification of the inferences is obtained. ; the latter will be incorporated into a forthcoming monograph, Attitude Problems.) /// [Jennifer Saul] This paper discusses the question of which verbs are intensional transitives. In particular, I ask which verbs Forbes should take to be intensional transitives. I argue that it is very difficult to arrive at a clear and plausible understanding of what an intensional transitive is-making it difficult to answer these questions. I end by briefly raising some questions about the usefulness of the category of intensional transitives. (shrink)

Time appears to us to pass. Some philosophers think that we should account for these experiences by appeal to change in what there unrestrictedly is . I argue that such an appeal can only be the beginning of an account of passage. To show this, I consider a minimal type of view—a purely topological view—that attempts to account for experiences as of passage by an appeal to ontological change and topological features of the present. I argue that, if ontological change (...) is needed to account for our experiences as of passage, then there are other features of our experiences as of passage that a purely topological view does not have the resources to explain. These features include the implacability of time’s passage, the orderliness of time’s passage, and the impossibility of a having a past that was never present. (shrink)

[Graeme Forbes] In I, I summarize the semantics for the relational/notional distinction for intensional transitives developed in Forbes (2000b). In II-V I pursue issues about logical consequence which were either unsatisfactorily dealt with in that paper or, more often, not raised at all. I argue that weakening inferences, such as 'Perseus seeks a mortal gorgon, therefore Perseus seeks a gorgon', are valid, but that disjunction inferences, such as 'Perseus seeks a mortal gorgon, therefore Perseus seeks a mortal gorgon or an (...) immortal gorgon', are invalid. Since 'a gorgon' and 'a mortal gorgon or an immortal gorgon' are extensionally and intensionally the same quantifier, it is not completely trivial to arrange the semantics of intensional transitives so that this classification of the inferences is obtained. (This paper is an abridged version of Forbes (2001a); the latter will be incorporated into a forthcoming monograph, Attitude Problems.) /// [Jennifer Saul] This paper discusses the question of which verbs are intensional transitives. In particular, I ask which verbs Forbes should take to be intensional transitives. I argue that it is very difficult to arrive at a clear and plausible understanding of what an intensional transitive is-making it difficult to answer these questions. I end by briefly raising some questions about the usefulness of the category of intensional transitives. (shrink)