The identity conception of truth holds that a thinkable is true just in case it is a fact. As such, it sets itself against correspondence theories of truth, while respecting the substantive role played by truth in respect of enquiry. In this article, I motivate and develop that view, and, in so doing, promote a particular conception of sense. This allows me to defend the view from two substantial criticisms. First, that the identity conception of truth is incoherent in respect (...) of its treatment of objects in the realm of reference, and, second, that it is committed to a view of the world in which ordinary objects have no place. (shrink)

In this paper, elementary but hitherto overlooked connections are established between Wittgenstein's remarks on mathematics, written during his transitional period, and free-variable finitism. After giving a brief description of theTractatus Logico-Philosophicus on quantifiers and generality, I present in the first section Wittgenstein's rejection of quantification theory and his account of general arithmetical propositions, to use modern jargon, as claims (as opposed to statements). As in Skolem's primitive recursive arithmetic and Goodstein's equational calculus, Wittgenstein represented generality by the use of free (...) variables. This has the effect that negation of unbounded universal and existential propositions cannot be expressed. This is claimed in the second section to be the basis for Wittgenstein's criticism of the universal validity of the law of excluded middle. In the last section, there is a brief discussion of Wittgenstein's remarks on real numbers. These show a preference, in line with finitism, for a recursive version of the continuum. (shrink)

Alan Turing anticipated many areas of current research incomputer and cognitive science. This article outlines his contributionsto Artificial Intelligence, connectionism, hypercomputation, andArtificial Life, and also describes Turing's pioneering role in thedevelopment of electronic stored-program digital computers. It locatesthe origins of Artificial Intelligence in postwar Britain. It examinesthe intellectual connections between the work of Turing and ofWittgenstein in respect of their views on cognition, on machineintelligence, and on the relation between provability and truth. Wecriticise widespread and influential misunderstandings of theChurch–Turing thesis (...) and of the halting theorem. We also explore theidea of hypercomputation, outlining a number of notional machines thatcompute the uncomputable. (shrink)

A survey of the field of hypercomputation, including discussion of a variety of objections.

Accelerating Turing machines are Turing machines of a sort able to perform tasks that are commonly regarded as impossible for Turing machines. For example, they can determine whether or not the decimal representation of contains n consecutive 7s, for any n; solve the Turing-machine halting problem; and decide the predicate calculus. Are accelerating Turing machines, then, logically impossible devices? I argue that they are not. There are implications concerning the nature of effective procedures and the theoretical limits of computability. Contrary (...) to a recent paper by Bringsjord, Bello and Ferrucci, however, the concept of an accelerating Turing machine cannot be used to shove up Searle's Chinese room argument. (shrink)

ABSTRACT Alice Ambrose is best known as Wittgenstein’s student during the 1930s. Her association with probably the most famous philosopher of the twentieth century contributes to her obscurity. Ambrose is referred to in historiography of this period as ‘follower’ or ‘disciple’ but never considered in her own right as a philosopher. The neglect of her place in the history of philosophy needs to be resisted. This paper explores some of Ambrose’s most interesting ideas from the early 1950s, when she developed (...) and expanded some of Wittgenstein’s inchoate suggestions and contributed to on-going debates about how to do philosophy and the role of language in the discipline. By combining an analysis of the 1950 paper “The Problem of Linguistic Inadequacy” and the 1952 paper “Linguistic Approaches to Philosophical Problems”, it will be seen that Ambrose rejects the idea that ordinary language can be improved and begins to develop the view that philosophical language adapts to usage. Thus, Ambrose does not blindly follow Wittgenstein but breaks with his idea that there is something inherently wrong with the way philosophers communicate. The paper also seeks to show how marginalized philosophers become obscured in the history of the subject through the example of Ambrose. (shrink)

Las máquinas aceleradas de Turing (ATMs) son dispositivos capaces de ejecutar súper-tareas. Sin embargo, el simple ejercicio de definirlas ha generado varias paradojas. En el presente artículo se definirán las nociones de súper-tarea y ATM de manera exhaustiva y se aclarará qué debe entenderse en un contexto lógico-formal cuando se pregunta por la existencia de un objeto. A partir de la distinción entre posibilidades lógicas y físicas se disolverán las paradojas y se concluirá que las ATMs son posibles y existen (...) como objetos abstractos. (shrink)