This paper explains the evolution of the modal marker<i>voire</i>in French, following an argumentative and pragmatic approach. Until the 16th century,<i>voire</i>can mark a confirmation in a dialogue. It can also appear inside a sentential structure. In both cases,<i>voire</i>is strongly assertive. This assertive value disappears in the course of the 17th century, and intra-sentential<i>voire</i>1 will give way to<i>voire</i>2, characteristic of Modern French.<i>Voire</i>is found nowadays inside a sentential structure, and it has a semantic value close to the Modern French<i>m&#234;me</i>or English<i>even</i>. But with<i>voire</i>2, the degree of adhesion by the speaker to his utterance has diminished. The weakening of the primary assertive value has resulted in an entirely different marker.