Conflicts between our best philosophical theories (BPTs) and our common beliefs are widespread. For example, if eliminativism is our BPT, then our BPT conflicts with common beliefs about the existence of middle-sized composite artifacts. “Compatibilism” is the name usually given to a theoretical attitude, according to which, in the case of a conflict between BPT and a common belief P, we should try to find a reconciliation. The two major variants of compatibilism are “semantic compatibilism” (SC) and “cognitive compatibilism” (CC). (...) According to SC, to be reconciled with BPT is the “real” version of the content of our ordinary assertions; according to CC, to be reconciled with BPT is the mental state we are “really” in while thinking P. In this paper, we present a new kind of compatibilism, epistemic compatibilism (EC). According to EC, to be reconciled with BPT is the explanation of why we believe that P. After presenting EC, we will argue that it fares better than SC and CC for at least two related reasons: EC does not rely on any form of what we call semantic or cognitive “recarving”; thus, EC avoids some sceptical problems that aect the other two versions of compatibilism. (shrink)

Commonsense ontology often conflicts with the ontology of our best scientific and philosophical theories. However, commonsense ontology, and commonsense belief systems in general, seems to be remarkably efficient and cognitively fundamental. In cases of contrast, it is better to find a way to reconcile commonsense and ”theoretical” ontologies. Given that commonsense ontologies are typically expressed within natural language, a classical procedure of reconciliation is semantical. The strategy is that of individuating the ”ontologically problematic” expressions of natural language and paraphrasing the (...) sentences in which they appear in a (formal) language whose commitments are compatible with those of our best theories. We believe that this strategy of reconciliation, though quite standard, especially in the philosophical literature, is problematic: for a start, it forces us to conclude that the ”real content” of our commonsense expressions and beliefs is different from what it appears. Commonsense ontology becomes just an illusion. We will thus propose an alternative approach: according to our view, a commonsense ontology is reconciled with a theoretical ontology in case it is shown that the explanation of why we believe in the existence of a problematic entity is compatible with our best theories. We will call this kind of reconciliation ”epistemic”. The advantage of an epistemic reconciliation is that commonsense ontology is treated in its own right and could be taken prima facie. Another advantage of the view is that epistemic reconciliation can be analysed through the notion of explaining away: a commonsense ontology is epistemically reconciled with a theoretical ontology if and only if the problematic entities of the commonsense ontology are explained away by ”respectable” entities of the theoretical ontology. In the final part of the paper, we sketch a formal analysis of explaining away. (shrink)

Can we explain why some propositions are necessary? Blackburn (Fact, science, and value. Blackwell, Oxford, 1987) has presented a dilemma aimed at showing that the necessity of a proposition cannot be explained either in the case where the explanans is another necessary proposition (necessity horn) or in the case where the explanans is a contingent proposition (contingency horn). Blackburn’s dilemma is intended to show that necessary truth is an explanatorily irreducible kind of truth: there is nothing that explains why propositions (...) are necessary, nothing that makes necessary necessary truths. In this paper, I criticize the contingency horn of Blackburn’s dilemma. On the one hand, I show that the official reconstruction of the horn uses a principle that is incompatible with the notion of explanation plausibly needed to explain why propositions are necessary; on the other, I show that a simpler formulation of the horn, which does not make use of such a controversial principle, makes essential use of principles that are incompatible with the idea that possibilities can have explanatory roles. I then defend the view that possibilities can have explanatory roles, and that the explanatory role of possibilities is best represented, within possible worlds, as the existence of trans-world relations of explanation. (shrink)

According to many actualist theories of modality, possible worlds should be identified with maximal and consistent sets of actually existing propositions called "world-stories". A set of propositions is said to be maximal if and only if for every (actually existing) proposition P , either P or its negation belongs to the set. In my talk, I will claim that this conception of maximality is problematic in case what has to be represented by a world-story is the possible non existence of (...) an actual individual. A representation of the possible non existence of an actual individual is either a representation that "encodes" the explicit information that the individual does not exist or a representation that does not contain any information about the individual in question. The former case corresponds to a world-story A that contains a proposition according to which a certain actually existing object, say O, does not exist, the latter case to a world-story B that simply does not contain any proposition about O. I will claim, however, that the first way is not good for the actualist (had A been the true world-story, something directly about a possible individual would have been true) while the second conflicts with the standard notion of maximality given above. In order to fix this problem, I will first propose to characterize the notion of "actual object that would have existed, had a certain set of propositions been true". I will then recursively define an alternative conception of maximality ("local maximality") that can be applied to world-stories aiming to represent, in an actualist acceptable way, the possible non-existence of an actual object. (shrink)

According to Williamson, our knowledge of metaphysical necessities and possibilities is just a “special case” of our knowledge of counterfactual conditionals. This subsumption of modal under counterfactual thinking mainly serves a methodological role: to sign the end of “philosophical exceptionalism” in modal epistemology, namely the view that our knowledge of metaphysical modalities is obtained by means of a special, dedicated, possibly a priori, capacity. In this paper, I show that a counterfactual approach to modal epistemology is structurally similar to more (...) traditional “conceivability-based” approaches. On this basis, I then show that the counterfactual approach suffers some of the same problems and I conclude that it is still based on a quite exceptional capacity to determine the truth of modal metaphysical claims. Given that, for Williamson, the epistemology of thought experiments should also be subsumed under the counterfactual approach, the problem I raise in this paper has consequences for his approach to thought experiments. (shrink)

In this article, I show that (i) from what I call a “Kripkean” account of the relations between conceivability and metaphysical necessities, (ii) an apparently plausible principle relating conceivability and epistemic modality, and (iii) the duality of epistemic modalities, one can show the utterly anti-Kripkean result that every metaphysical necessity is an epistemic necessity. My aim is to present and diagnose the problem and evaluate the costs of some possible Kripkean reactions. In particular, I will evaluate the consequences and theoretical (...) costs of rejecting the main ingredients of the argument, namely that we cannot genuinely conceive the negations of metaphysical necessities, that there is no postulated relation between conceivability and epistemic possibility (actually, between unconceivability and epistemic impossibility), and that epistemic possibility and necessity are not dualities. (shrink)

The notion of validity for modal languages could be defined in two slightly different ways. The first is the original definition given by S. Kripke, for which a formula φ of a modal language L is valid if and only if it is true in every actual world of every interpretation of L. The second is the definition that has become standard in most textbook presentations of modal logic, for which a formula φ of L is valid if and only (...) if it is true in every world in every interpretation of L. For simple modal languages, “Kripkean validity” and “Textbook validity” are extensionally equivalent. According to E. Zalta, however, Textbook validity is an “incorrect” definition of validity, because: (i) it is not in full compliance with Tarski’s notion of truth; (ii) in expressively richer languages, enriched by the actuality operator, some obviously true formulas count as valid only if the Kripkean notion is used. The purpose of this paper is to show that (i) and (ii) are not good reasons to favor Kripkean valid- ity over Textbook validity. On the one hand, I will claim that the difference between the two should rather be seen as the result of two different conceptions on how a modal logic should be built from a non-modal basis; on the other, I will show the advantages, for the question at issue, of seeing the actuality operator as belonging to the family of two-dimensional operators. (shrink)

Aaccording to D. K. lewis (1973), would-couterfactuals and might-counterfactuals are duals. from this, it follows that the negation of a would-counterfactual is equiv- alent to the corresponding “might-not”-counterfactual and that the negation of a might-counterfactual is equivalent to the corresponding “would-not”- counterfactual. there are cases, however, where we seem to be entitled to accept the would- counterfactual and we are also equally entitled to accept the corresponding might-not-counterfactual and cases where we seem to be entitled to accept the might-counterfactual without (...) being equally entitled to reject the corresponding would-not-counterfactual. In this paper, I will show that a distinction between two types of rejections for counterfactuals (p-rejection and s-rejection) and the recognition that might-not-counterfactuals may play the role of p-rejections (by an application to counterfactuals of the lewisian approach to conversational scores) could explain why the problematic cases should not be seen as cases where the duality of would- and might-counterfactuals fails. (shrink)

In this paper, I claim that two ways of defining validity for modal languages (“real-world” and “general” validity), corresponding to distinction between a correct and an incorrect way of defining modal valid- ity, correspond instead to two substantive ways of conceiving modal truth. At the same time, I claim that the major logical manifestation of the real- world/general validity distinction in modal propositional languages with the actuality operator should not be taken seriously, but simply as a by-product of the way (...) in which the semantics of such an operator is usually given. (shrink)

Timothy Williamson in his article "Necessary Existents" presents a proof of the claim that everything necessarily exists using just three seemingly uncontroversial principles relating the notions of proposition with those of truth and existence. The argument, however, may be easily blocked once the distinction, introduced by R. M. Adams, between the notions of a proposition being true in a world and of (or at) a world is introduced. In this paper I defend the plausibility of the notion of a proposition's (...) being true of a world by rejecting two criticisms of it raised by Williamson; in the final section, I present a conception of propositions, according to which they are equivalence classes of mental representations, for which at least one of the principles comes out as false. (shrink)

The entailment connective is introduced by Priest (2006b). It aims to capture, in a dialetheically acceptable way, the informal notion of logical consequence. This connective does not “fall foul” of Curry’s Paradox by invalidating an inference rule called “Absorption” (or “Contraction”) and the classical logical theorem called “Assertion”. In this paper we show that the semantics of entailment, given by Priest in terms of possible worlds, is inadequate. In particular, we will argue that Priest’s counterexamples to Absorption and Assertion use (...) in the metalanguage a dialetheically unacceptable principle. Furthermore, we show that the rejection of Assertion undermines Priest’s claim that the entailment connective expresses the notion of logical consequence. (shrink)

Aim of this paper is to present and evaluate linguistic ersatzism, an actualist metaphysics of modality according to which possible worlds are maximal and consistent sets of sentences. In the first section, I make some general considerations about reductive theories of modality and the relation between modality and possible worlds, in the second I present a specific version of linguistic ersatzism and in the last section I present what I take to be the major problem for this kind of theories, (...) namely that of finding a suitable surrogate for the possibilist’s notion of a merely possible object. (shrink)