Within the field of Discourse Analysis (Pêcheux) and psychoanalysis, this work states interdiction and silence as constituents and founders of the discourse. In short, we claim that what makes it possible to say anything is that it is not possible to say it all, so something must remain unsaid. The logic principle here is that the contradiction, the excluded founds the possible. For such task we use the logic square. We also propose and build a square of the saying or of the utterances. The analysis made here points toward the existence of the impossible in language, and also indicates how important a modal approach of language can be.
Discourse; interdiction; silence
