New York Philosophical Logic Group Spring 2015 Schedule

New York Philosophical Logic Group Spring 2015 Schedule

New York Philosophical Logic Group

Spring Semester 2015

This semester the group will meet on Thursdays from 5-7 pm, in the Philosophy Department at NYU: Room 302, 5 Washington Place. We will meet roughly once a month. The provisional programme is as follows:

February 12: Mel Fitting, CUNY, “Justification Logics”

March 12: Harvey Lederman, Oxford, “Standard State Space Models of Unawareness”

May 7: Delia Graf Fara, Princeton, “A Problem for Predicativism Solved by Predicativism”

Organized by Graham Priest


Next talk:

Delia Graff Fara, Princeton
A Problem for Predicativism Solved by Predicativism

Abstract: Consider the following sentences:

(1) In every race, the colt won;
(2) In every race, John won.

John Hawthorne and David Manley say that the difference between these two sentences raises a problem for Predicativism about names (2012, 236). According to the currently more standard version of Predicativism about names, a bare singular name in argument position, like ‘John’ in (2), is embedded in (what I call) a denuded definite description, a definite description ‘Øthe John’, where ‘Øthe’ is an unpronounced definite article. The problem is supposed to be that (1) permits a covarying reading that allows for different races to have been won by different colts, while (2) does not permit a covarying reading — it can be true only if there is a single John that won every race. But, the objection runs, if the name ‘John’ is really embedded in a denuded definite description ‘Øthe John’, then the two sentences are structurally parallel and should not differ with respect to covariation. Appealing to Jason Stanley’s “Nominal Restriction” (the 2005 version), I show that the difference between the two sentences above not only does not raise a problem for Predicativism, but is actually predicted by it.



Thurs March 12, 5-7 pm.
Room 302, 5 Washington Place.  (Department of Philosophy, NYU.)
Harvey Lederman, NYU (with Peter Fritz, Oxford)

Standard State Space Models of Unawareness

The impossibility theorem of Dekel, Lipman and Rustichini (1998) has been thought to demonstrate that standard state-space models cannot be used for modeling unawareness. We show that Dekel, Lipman and Rustichini do not establish this claim. Distinguishing three notions of awareness, we argue that although one of them cannot be adequately modeled using standard state spaces, there is no reason to think that standard state spaces cannot provide models of the other two notions. Moreover, standard space models of these notions are attractively simple. As we show, they allow us to prove completeness and decidability results with ease, to carry over standard techniques from decision theory, and to add propositional quantifiers straightforwardly.



First Meeting, Spring 2015
Thurs Feb 12, 5-7 pm.
Room 302, 5 Washington Place.  (Department of Philosophy, NYU.)
Melvin Fitting, CUNY

Justification Logics

Gödel inaugurated a project of finding an arithmetic semantics for intuitionistic logic, but did not complete it. It was finished by Sergei Artemov, in the 1990’s. As part of this work, Artemov introduced the first justification logic, LP, (standing for logic of proofs). This is a propositional modal-like logic, with an infinite family of proof or justification terms, and can be seen as an explicit version of the well-known modal logic S4. There is a possible world semantics for LP (due to me). Since then, many other justification logic/modal logic pairs have been investigated, and justification logic has become a subject of independent interest, going beyond the original connection with intuitionistic logic. It is now known that there are infinitely many justification logics, but the exact extent of the family is not known. Justification logics are connected with their corresponding modal logics via Realization Theorems. A Realization Theorem connecting LP and S4 has a constructive proof, but there are other cases for which realization holds, but it is not known if a constructive proof exists. More recently, a firstorder version of LP has been developed, but I will not talk about it in detail. I will present a sketch of the basic propositional ideas.

Image: KeithMichaelNYC