Cet article a pour but d’étudier les perspectives que fournit l’approche performative de l’argument, afin de répondre à deux questions classiques liées à l’interprétation du cogito. D’abord : quel type de contrainte logique ou non logique le « donc » exprime-t-il dans la formulation de cet argument? Ensuite : quel type d’existence est manifesté par l’argument, ou par sa formulation par Hintikka : « Cogito ergo quis est? ».

According to Alfred Tarski’s classical definition, logical consequence is necessary and formal. This paper focuses on the question: In what sense (if any) is material consequence a logical relation? For Tarski, material consequence has no modal force. Treating all terms (of a language with a fixed domain) as logical, he reduces logical consequence to material consequence. Thus, Tarskian material consequence seems to be a logical oxymoron designed to emphasize the importance of the distinction between logical and extra-logical terms for the (...) definition of logical consequence. Historically, however, there have been different approaches to material consequences. This paper attempts to provide an investigation into the parallels between Tarski’s dichotomy of formal and material consequence and the modern. (shrink)