Know Techn Pol (2010) 23:25–40
DOI 10.1007/s12130-010-9098-4
SPECIAL ISSUE
A Classical Prejudice?
Patrick Allo
Received: 28 April 2010 / Accepted: 18 May 2010 / Published online: 24 July 2010
© Springer Science+Business Media B.V. 2010
Abstract In this paper, I reassess Floridi’s solution to the Bar-Hillel–Carnap
paradox (the information yield of inconsistent propositions is maximal) by
questioning the orthodox view that contradictions cannot be true. The main
part of the paper is devoted to showing that the veridicality thesis (semantic
information has to be true) is compatible with dialetheism (there are true
contradictions) and that, unless we accept the additional non-falsity thesis
(information cannot be false), there is no reason to presuppose that there is
no such thing like contradictory information.
Keywords Contradiction · Dialetheism · Logic · Method of abstraction ·
Paradox · Philosophy of information · Semantic information ·
Veridicality thesis
1 Introduction
The classical theory of semantic information, as formulated in Carnap and Bar-
Hillel (1952), is a close relative of the usual model theoretic characterisation
1
1
The original version is based on state descriptions instead of models, but as may be seen from
Kemeny (1953), it can be so reformulated.
Postdoctoral Fellow of the Science Foundation (FWO).
P. Allo (B )
Centre for Logic and Philosophy of Science, Vrije Universiteit Brussel,
Pleinlaan 2, 1050 Brussel, Belgium
e-mail: patrick.allo@vub.ac.be
P. Allo
IEG, Oxford University, Oxford, UK
Author's personal copy