Adding a Conditional to Kripke’s Theory of Truth

Kripke’s theory of truth (Kripke, The Journal of Philosophy72(19), 690–716; 1975) has been very successful but shows well-known expressive difficulties; recently, Field has proposed to overcome them by adding a new conditional connective to it. In Field’s theories, desirable conditional and truth-theoretic principles are validated that Kripke’s theory does not yield. Some authors, however, are dissatisfied with certain aspects of Field’s theories, in particular the high complexity. I analyze Field’s models and pin down some reasons for discontent with them, focusing on the meaning of the new conditional and on the status of the principles so successfully recovered. Subsequently, I develop a semantics that improves on Kripke’s theory following Field’s program of adding a conditional to it, using some inductive constructions that include Kripke’s one and feature a strong evaluation for conditionals. The new theory overcomes several problems of Kripke’s one and, although weaker than Field’s proposals, it avoids the difficulties that affect them; at the same time, the new theory turns out to be quite simple. Moreover, the new construction can be used to model various conceptions of what a conditional connective is, in ways that are precluded to both Kripke’s and Field’s theories.     

Factor analysis models via I-divergence optimization

Given a positive definite covariance matrix \(\widehat{\Sigma }\) of dimension n, we approximate it with a covariance of the form \(HH^\top +D\), where H has a prescribed number \(k<n\) of columns and \(D>0\) is diagonal. The quality of the approximation is gauged by the I-divergence between the zero mean normal laws with covariances \(\widehat{\Sigma }\) and \(HH^\top +D\), respectively. To determine a pair (H, D) that minimizes the I-divergence we construct, by lifting the minimization into a larger space, an iterative alternating minimization algorithm (AML) à la Csiszár–Tusnády. As it turns out, the proper choice of the enlarged space is crucial for optimization. The convergence of the algorithm is studied, with special attention given to the case where D is singular. The theoretical properties of the AML are compared to those of the popular EM algorithm for exploratory factor analysis. Inspired by the ECME (a Newton–Raphson variation on EM), we develop a similar variant of AML, called ACML, and in a few numerical experiments, we compare the performances of the four algorithms.     

Non-reflexivity and Revenge

Journal of Philosophical Logic - We present a revenge argument for non-reflexive theories of semantic notions – theories which restrict the rule of assumption, or (equivalently) initial...     

Understanding Co-Occurring ADHD and Anxiety Symptoms within a Developmental Framework: Risk and Protective Factors of Early Temperament and Peer Relations

Research on Child and Adolescent Psychopathology - Symptoms of ADHD and anxiety often co-occur, yet we are limited in our understanding of which children with ADHD symptoms are more likely to...     

Mark,Image, Sign: A Semiotic Approach to Spinoza

Instead of reading Spinoza's account of the imagination in an anthropocentric way, as dependent on the traditional doctrine of human faculties, the author considers it as a consequence of his physics and cosmology. Knowledge by signs, as Spinoza calls imagination, has to be rooted in his theory of marks and images, and concerns all beings (human and non human) that are capable of marking and being marked by other bodies in the infinite semiosis of nature.     

“Where You Lead,I Will Follow”: Partisan Cueing on High-Salience Issues in a Turbulent Multiparty System

The ability of parties to not only reflect, but actually shape, citizens' preferences on policy issues has been long debated, as it corresponds to a fundamental prediction of classic party identification theory. While most research draws on data from the United States or studies of low-salience issues, we exploit the unique opportunity presented by the 2013 Italian election, with the four major parties of a clear multiparty setting holding distinct positions on crucial issues of the campaign. Based on an experimental design, we test the impact of party cues on citizens' preferences on high-salience issues. The results are surprising: Despite a party system in flux (with relevant new parties) and a weakening of traditional party identities, we find large, significant partisan-cueing effects in all the three experimental issues, and for voters of all the major Italian parties—both old and new, governmental and opposition, ideologically clear or ambiguous.