Spring 2016: Talk at the Higher Seminar in Theoretical Philosophy

Tuesday, April 26th, 2016, 13.15-15.00
Philosophy Department, Lund University
LUX B429
Seminar website

Title:
Can Church’s Thesis be Viewed as a Carnapian Explication

Abstract:

Turing and Church provided two different definitions of computability that turned out to be extensionally equivalent. Since the definitions refer to different properties they cannot both be adequate conceptual analysis of the concept of computability. This insight has led to a debate concerning which definition is adequate. Tennant and others have suggested, in effect, that this philosophical debate, which shows few signs of convergence on one view, can be circumvented by regarding the theses instead as explications, or “rational reconstructions”, in Carnap’s sense. This move opens up for the possibility that both can be adequate, albeit in their own different ways. In this paper we focus on the question whether Church’s thesis can be seen as an explication in the framework of the Peano axiom system in the light of the fact that Carnap himself seems to rule out this possibility. We consider a recently proposed interpretation of Carnap’s view due to Dulith-Novaes and Reck that, if satisfactory, would resolve this conflict, finding their reading of Carnap problematic. Finally, we consider various ways of formulating Church’s thesis so that it becomes compatible with explication as Carnap viewed it.

Summer 2014: Paper publication

A paper of mine “From the Computability over Strings of Characters to Natural Numbers” just appeared as a chapter of Olszewski, Brozek, Urbanczyk (eds.), “Church’s Thesis: Logic, Mind and Nature”, Copernicus Center Press, 2014.

Abstract

This paper describes the concept of natural numbers as inherited from the concept of computability, itself understood in terms of character manipulation. The intention is to show that “computation over strings of characters” is a primitive notion that does not presuppose either any other notion of computability, or any independent conception of natural numbers. On this basis, I argue that natural numbers can be characterized, adequately, as abstract mathematical entities named by strings of characters on which computations can be performed: in particular computations of successor, addition and multiplication.

Preprint is available on my academia.com webpage.