Andrea Iacona

This paper deals with the question of what it is for a quantifier expression to be vague. First it draws a distinction between two senses in which quantifier expressions may be said to be vague, and provides an account of the distinction which rests on independently grounded assumptions. Then it suggests that, if some further assumptions are granted, the difference between the two senses considered can be represented at the formal level. Finally, it outlines some implications of the account provided which bear on three debated issues concerning quantification.

Classical logic rests on the assumption that there are two mutually exclusive and jointly exhaustive truth values. This assumption has always been surrounded by philosophical controversy. Doubts have been raised about its legitimacy, and hence about the legitimacy of classical logic. Usually, the assumption is stated in the form of a general principle, namely the principle that every proposition is either true or false. Then, the philosophical controversy is often framed in terms of the question whether every proposition is either true or false. The main purpose of the paper is to show that there is something wrong in this way of putting things. The point is that the common way of understanding the controversial assumption is misconceived, as it rests on a wrong picture of propositions. In the first part of the paper I outline this picture and I argue against it. In the second part I sketch a different picture of propositions and I suggest how this leads to conceive the issue of classical logic in different terms.

One of the most common strategies in philosophical dispute is that of accusing the opponent of begging the question, that is, of assuming or presupposing what is to be proved. Thus, it happens quite often that the credibility of a philosophical argument is infected by the suspicion of begging the question. In many cases it is an open question whether the suspicion is grounded, and the answer lurks somewhere in the dark of what the proponent of the argument does not say. This is why it may take years, or even centuries, before the begging of the question is brought to light. But few philosophers would deny that once it is established that a certain argument begs the question, that argument has to be rejected without hesitation: question-begging arguments are bad arguments, hence one should not appeal to them. Logicians traditionally classify begging the question as a fallacy, that is, as a bad reasoning that seems good at first sight. The fallacy is known under the name of petitio principii. This paper originated in our dissatisfaction with definitions of petitio principii found here and there in logic textbooks. Although it is uncontroversial that there is something wrong with begging the question, it is not clear from those definitions what is wrong.

The aim of this paper is to show that in order to make sense of the ascription of truth and falsity to the things we say it is essential to acknowledge a divergence between two basic intuitions. According to one of them it is plausible to talk of what is said as what the speaker has in mind. According to the other it is plausible to talk of what is said as the bearer of truth or falsity. The paper presents three cases in which these two intuitions seem not to coincide, and shows how this lack of coincidence can be accounted for in terms of underspecification.

This paper investigates the logic of Ockhamism, a view according to which future contingents are either true or false. Several attempts have been made to give rigorous shape to this view by defining a suitable formal semantics, but arguably none of them is fully satisfactory. The paper draws attention to some problems that beset such attempts, and suggests that these problems are different symptoms of the same initial confusion, in that they stem from the unjustified assumption that the actual course of events must be represented in the semantics as a distinguished history, the Thin Red Line

This paper defends the thesis that counterfactuals are strict conditionals. Its purpose is to show that there is a coherent view according to which counterfactuals are strict conditionals whose antecedent is stated elliptically. Section 1 introduces the view. Section 2 outlines a response to the main argument against the thesis that counterfactuals are strict conditionals. Section 3 compares the view with a proposal due to Aqvist, which may be regarded as its direct predecessor. Sections 4 and 5 explain how the view diers from the theories of counterfactuals advocated by Stalnaker and Lewis, and from some contextualist strict conditional accounts of counterfactuals that have emerged recently. Finally, section 6 addresses the thorny issue of disjunctive antecedents.

So far, T×W frames have been employed to provide a semantics for a language of tense logic that includes a modal operator that expresses historical necessity. The operator is defined in terms of quantification over possible courses of events that satisfy a certain constraint, namely, that of being alike up to a given point. However, a modal operator can as well be defined without placing that constraint. This paper outlines a T×W logic where an operator of the latter kind is used to express the epistemic property of definiteness. Section 1 provides the theoretical background. Sections 2 and 3 set out the semantics. Sections 4 and 5 show, drawing on established results, that there is a sound and complete axiomatization of the logic outlined.

Over the past few years, the tree model of time has been widely employed to deal with issues concerning the semantics of tensed discourse. The thought that has motivated its adoption is that the most plausible way to make sense of indeterminism is to conceive of future possibilities as branches that depart from a common trunk, constituted by the past and the present. However, the thought still needs to be further articulated and defended, and several important questions remain open, such as the question of how actuality can be understood and formally represented in a branching framework. The present volume is intended to be a 360 degree reflection on the tree model. The contributions is gathers concern the model and its alternatives, both from a semantic and from a metaphysical point of view. ​

Many arguments are affected by context sensitivity, because they include sentences that have different truth conditions in different contexts. Therefore, it is natural to think that a general criterion for evaluating arguments must take context sensitivity into account. One way to give substance to that thought is provided by the definition of validity offered by David Kaplan within his theory of indexicals. However, the route indicated by Kaplan is hindered by a problem whose importance is often underestimated. This paper explores a different route, and outlines a definition of validity that does not run into that problem. Its moral is that Kaplan's definition is not the only plausible definition. This is not to say that the definition outlined is the only plausible definition or that it is correct in some absolute sense. There might be equally important problems with it that the paper does not take into account. But until such problems are found and brought up, the departure from Kaplan's route remains a viable option.

In a paper called 'Definiteness and Knowability', Tim Williamson addresses the question whether one must accept that vagueness is an epistemic phenomenon if one adopts classical logic and a disquotational principle for truth. Some have suggested that one must not, hence that classical logic and the disquotational principle may be preserved without endorsing epistemicism. Williamson’s paper, however, finds ‘no plausible way of substantiating that possibility’. Its moral is that ‘either classical logic fails, or the disquotational principle does, or vagueness is an epistemic phenomenon’. The moral of this paper, on the contrary, is that there is a plausible way of substantiating that possibility. The option it contemplates looks like a view that Williamson dismisses at the beginning of his paper, and that others regard as unworthy of serious consideration.