The question of identity of evidence, the normalization thesis, and some of its basic semantic assumptions

Abstract

The article offers, first, a characterisation of the question of identity of pro-ofs as a problem concerning the semantics of deductive arguments, pertai-ning to logic and philosophy of language. In the sequel, a description of the main formal and conceptual aspects of the normalisation thesis – probably the most well developed formal approach to identity of proofs in the literature so far, proposed as a conjecture by Prawitz in 1971 – is given. Finally, some of the semantical assumptions that form the basis of the thesis’ formulation –important components of the representationalist view of proofs which it ins-tantiates – are exposed and discussed as to its relevant consequences and pos-sible motivations. Apart from the goals directly related to its contents, the ar-ticle has the pedagogical aim of facilitating and stimulating the consideration of the question of identity of proofs amongst the portuguese-speaking philo-sophical community.