Online research in philosophy

Most theories of conditionals and attitudes do not analyze either phenomenon in terms of the other. A few view attitude reports as a species of conditionals (e.g. Stalnaker 1984, Heim 1992). Based on evidence from Kalaallisut, this paper argues for the opposite thesis: conditionals are a species of attitude reports. The argument builds on prior findings that conditionals are modal topic-comment structures (e.g. Haiman 1978, Bittner 2001), and that in mood-based Kalaallisut English future (e.g. Ole will win) translates into a factual report of a prospect-oriented attitudinal state (e.g. expectation or anxiety, see Bittner 2005). It is argued that in conditionals the antecedent introduces a topical subdomain of an input modal base (Kratzer 1981) and requires the consequent to comment. The comment is a factual report of an attitude to the topical antecedent sub-domain.

An examination of a particular passage in Cicero's De fato?Fat. 13?17?is crucial to our understanding of the Stoic theory of the truth-conditions of conditional propositions, for it has been uniquely important in the debate concerning the kind of connection the antecedent and consequent of a Stoic conditional should have to one another. Frede has argued that the passage proves that the connection is one of logical necessity, while Sorabji has argued that positive Stoic attitudes toward empirical inferences elsewhere suggest that that cannot be the right interpretation of the passage. I argue that both parties to the debate have missed a position somewhere between them which both renders a connection between antecedent and consequent that is not merely empirical and makes sense of the actual uses to which the Stoics put the conditional. This will be an account which grounds the connection between antecedent and consequent in a prolêpsis, a special kind of concept which plays a special epistemological role for the Stoics, especially in grounding scientific explanations. My contention will be that Stoic conditionals are true when there is a conceptually necessary connection between antecedent and consequent such that the former explains the latter via a prolêpsis.

The paper presents an alternative substitutional semantics for first-order modal logic which, in contrast to traditional substitutional (or truth-value) semantics, allows for a fine-grained explanation of the semantical behavior of the terms from which atomic formulae are composed. In contrast to denotational semantics, which is inherently reference-guided, this semantics supports a non-referential conception of modal truth and does not give rise to the problems which pertain to the philosophical interpretation of objectual domains (concerning, e.g., possibilia or trans-world identity). The paper also proposes the notion of modality de nomine as an alternative to the denotational notion of modality de re.

This is indeed a very nice draft that I have read with great pleasure, and that has helped me to better understand the completeness proof for LCC. Modal fixed point logic allows for an illuminating new version (and a further extension) of that proof. But still. My main comment is that I think the perspective on substitutions in the draft paper is flawed. The general drift of the paper is that relativization, (predicate) substitution and product update are general operations on models, and that it is important to check whether given logical languages are closed under these operations. FO logic is closed under relativization, predicate substitution and product constructions (such as those involved in relative interpretation). The minimal modal logic is closed under relativization, which explains the reduction of epistemic logic (withhout common knowledge) + public announcement to epistemic logic simpliciter (as observed in Van Benthem, [2]). The reduction breaks down as soon as one adds common knowledge. The minimal modal logic is also closed under substitution, which explains the reduction of epistemic logic plus (publicly observable) factual change to epistemic logic simpliciter, via the following reduction axioms (I use !p := φ for the operation of publicly changing the truth value of p to φ): [!p := φ]p ↔ φ [!p := φ]q ↔ q (p and q syntactically different ) [!p := φ]¬ψ ↔ ¬[!p := φ]ψ [!p := φ](ψ1 ∧ ψ2) ↔ [!p := φ]ψ1 ∧ [!p := φ]ψ2 [!p := φ][i]ψ ↔ [i][!p := φ]ψ Unlike the case of relativisation, this can be extended to the case of epistemic logic with common knowledge, by means of: [!p := φ]CGψ ↔ CG[!p := φ]ψ We get the following..

The benchmark theory of conditionals maintains that conditionals quantify over a contextually restricted domain of worlds (Kratzer 1991). They are modal statements. The antecedent contributes to the interpretation of the whole conditional a proposition, a set of worlds. Conditionals quantify over a contextually restricted domain of worlds in which the proposition that the antecedent expresses is true. This is all antecedents do. In particular, the semantic import of its tense and mood inflection is neglected: it is - at most - a merely formal reflection of the type of modal in the consequent (Fintel 1998; Heim 1992; Kratzer 1991).

We present a semantic study of a family of modal intuitionistic linear systems, providing various logics with both an algebraic semantics and a relational semantics, to obtain completeness results. We call modality a unary operator on formulas which satisfies only one rale (regularity), and we consider any subsetW of a list of axioms which defines the exponential of course of linear logic. We define an algebraic semantics by interpreting the modality as a unary operation on an IL-algebra. Then we introduce a relational semantics based on pretopologies with an additional binary relationr between information states. The interpretation of is defined in a suitable way, which differs from the traditional one in classical modal logic. We prove that such models provide a complete semantics for our minimal modal system, as well as, by requiring the suitable conditions onr (in the spirit of correspondence theory), for any of its extensions axiomatized by any subsetW as above. We also prove an embedding theorem for modal IL-algebras into complete ones and, after introducing the notion of general frame, we apply it to obtain a duality between general frames and modal IL-algebras.

In contemporary discussions of the Ramsey Test for conditionals, it is commonly held that (i) supposing the antecedent of a conditional is adopting a potential state of full belief, and (ii) Modus Ponens is a valid rule of inference. I argue on the basis of Thomason Conditionals (such as ‘If Sally is deceiving, I do not believe it’) and Moore’s Paradox that both claims are wrong. I then develop a double-indexed Update Semantics for conditionals which takes these two results into account while doing justice to the key intuitions underlying the Ramsey Test. The semantics is extended to cover some further phenomena, including the recent observation that epistemic modal operators give rise to something very like, but also very unlike, Moore’s Paradox.

It often seems that what one ought to do depends on what contingent ends one has adopted and the means to pursuing them. Imagine, for example, that you are applying for jobs, and a particularly attractive one comes your way. It offers excellent colleagues in a desirable location, the pay is good, and acquiring a job like this is one of your ends. If practicing your job talk is a means to getting the job, the following seems true: (1) If you want1 to get the job, then you ought to practice your job talk. Let us call conditional ought sentences that purport to express an end in the antecedent and a means to the end in the consequent end-given oughts. Some end-given oughts run into the problem of detachment; i.e., some end-given oughts seem true, and yet we do not think the consequent by itself, detached from the conditional, is true even if the antecedent is true. Consider a case where you want revenge on Bill for some slight offense. You happen to have the opportunity to poison Bill’s drink while he is away, which is the only thing that would lead to his demise. What of: (2) If you want to kill Bill, then you ought to poison his drink. (2) runs up against the problem of detachment because of the following modus ponens argument: • If you want to kill Bill, then you ought to poison his drink. • You want to kill Bill. • Therefore, you ought to poison his drink. In fact, you ought not poison Bill’s drink. You ought to avoid him and seek counseling.

This article is oriented toward the use of modality in artificial intelligence (AI). An agent must reason about what it or other agents know, believe, want, intend or owe. Referentially opaque modalities are needed and must be formalized correctly. Unfortunately, modal logics seem too limited for many important purposes. This article contains examples of uses of modality for which modal logic seems inadequate.I have no proof that modal logic is inadequate, so I hope modal logicians will take the examples as challenges.

to use David Chalmers's jargon) claim that though zombies are conceivable, they are not metaphysically possible. This article calls this position regarding the relation between metaphysical and epistemic modality "modal autonomism," as opposed to the "modal rationalism" endorsed by David Chalmers and Frank Jackson, who insist on a deep link between the two forms of modality. This article argues that the defense of modal rationalism presented in Chalmers and Jackson (2001) begs the question against the type-B materialist/modal autonomist. The argument proceeds as follows. Modal rationalists claim that for all nonphenomenal macro properties, the appropriate supervenience conditional is both necessary and a priori. Hence, type-B materialists must engage in special pleading when they claim that the relevant supervenience conditional for phenomenal properties, expressing the supervenience of the phenomenal on the physical, is necessary but not a priori. However, what Chalmers and Jackson demonstrate, if anything, is that the conditional that includes all the microphysical plus the phenomenal in the antecedent, and nonphenomenal macro facts (such as facts about water and other natural kinds, among other things) in the consequent, is a priori. The question arises why, since facts about water and the like do not metaphysically supervene on the phenomenal facts, is it appropriate to include the phenomenal facts in the antecedent of the relevant supervenience conditional. This article argues for the following claims: First, that it's crucial to the general semantic framework Chalmers and Jackson defend that they do include the phenomenal facts in the supervenience conditional; without them, the conditional would not be a priori. Second, that the only way to argue from the a priori character of these conditionals to the applicability of modal rationalism to the nonphenomenal cases is to rely either on modal rationalism itself or on the denial of type-B materialism. Obviously, in the context of this argument, either way would beg the question. CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?