In Philosophical Logic, the Liar Paradox has been used to motivate the introduction of both truth value gaps and truth value gluts. Moreover, in the light of “revenge Liar” arguments, also higher-order combinations of generalized truth values have been suggested to account for so-called hyper-contradictions. In the present paper, Graham Priest's treatment of generalized truth values is scrutinized and compared with another strategy of generalizing the set of classical truth values and defining an entailment relation on the resulting sets of (...) higher-order values. This method is based on the concept of a multilattice. If the method is applied to the set of truth values of Belnap's “useful four-valued logic”, one obtains a trilattice, and, more generally, structures here called Belnap-trilattices. As in Priest's case, it is shown that the generalized truth values motivated by hyper-contradictions have no effect on the logic. Whereas Priest's construction in terms of designated truth values always results in his Logic of Paradox, the present construction in terms of truth and falsity orderings always results in First Degree Entailment. However, it is observed that applying the multilattice-approach to Priest's initial set of truth values leads to an interesting algebraic structure of a “bi-and-a-half” lattice which determines seven-valued logics different from Priest's Logic of Paradox. (shrink)

Text: Reproduktion nach Scan der Ausgabe von 1934, Verlag von J. C. B. Mohr (Paul Siebeck) in Tübingen. - Von dem kleinen Buch, das ich hier der Öffentlichkeit übergebe, bitte ich den Leser, nichts anderes zu erwarten, als das, was sein Titel ausdrücklich sagt. Es handelt sich in ihm nicht etwa um die Grundlinien eines Systems der Philosophie, sondern ausschließlich um dessen Probleme, und wenn diese sich auch nicht darlegen lassen, ohne die Richtung anzudeuten, in der das System bei der (...) Ausführung sich zu bewegen hätte, so sollen doch in dieser Schrift hauptsächlich Fragen gestellt, nicht Antworten gegeben werden. Oft brechen die Darlegungen dort ab, wo mancher Leser glauben kann, daß die größten Schwierigkeiten noch ungelöst sind. Ja mehr: nur die Grundprobleme der Philosophie werden erörtert, und das Eingehen auf Sonderfragen ist fast überall vermieden. Einzelheiten sind dann allein herangezogen worden, wenn es zur Verdeutlichung der Hauptbegriffe wünschenswert erschien. [Auszug aus dem Vorwort des Buches]. (shrink)

The famous “slingshot argument” developed by Church, Gödel, Quine and Davidson is often considered to be a formally strict proof of the Fregean conception that all true sentences, as well as all false ones, have one and the same denotation, namely their corresponding truth value: the true or the false. In this paper we examine the analysis of the slingshot argument by means of a non-Fregean logic undertaken recently by A.Wóitowicz and put to the test her claim that the slingshot (...) argument is in fact circular and presupposes what it intends to prove. We show that this claim is untenable. Nevertheless, the language of non-Fregean logic can serve as a useful tool for representing the slingshot argument, and several versions of the slingshot argument in non-Fregean logics are presented. In particular, a new version of the slingshot argument is presented, which can be circumvented neither by an appeal to a Russellian theory of definite descriptions nor by resorting to an analogous “Russellian” theory of λ–terms. (shrink)

Achievement test differences between boys and girls and between young men and young women, mostly favoring males, extend far beyond mathematics. Such pervasive differences, illustrated here, may require an explanatory theory broader than Geary's.