[en] The aim of this paper is to lay emphasis on the connection between the mind-body problem and the theory of language which is developed in early-modern philosophy by Descartes and post-cartesian philosophers such as Arnauld, Lancelot and Nicole, and also Géraud de Cordemoy. Whereas human psychophysical identity becomes a theoretical enigma, in the mechanistic and "dualistic" framework of the seventeenth century, new conceptions of linguistic activity are worked out, which deal with the "arbitrary nature of the sign", that is with the notion of a non natural association between the material dimension of signification (sounds, letters) on the one hand, and mental representation, or meaning, on the other hand. The main paradox, which is at stake in these conceptions of language, is such as follows : speech acts are essentially conceived of, in Descartes' philosophy, as inner acts, in so far as their function is to express an inner principle in man, i.e thought, and not as outer acts, that define the merely physical operations of beasts or machines. In that respect, language, as any kind of mental activity, seems to be theorized within the general framework of substance dualism, and of the distinctio realis which divides human mind from human body. Yet, the very notion of a linguistic activity, as public expression of mental states, involves the embodiment of the speaking subject, that is of the "real man", consisting of a mind and a body. This association of mental and physical, this psychophysical unity, which is postulated in the conception of human identity, seems also involved, for instance, in the theory of linguistic signification, such as it is set out by Port-Royal philosophers. But the relationship between the material and the "spiritual" sides of the linguistic sign, in this philosophical tradition, cannot be a natural one, as it is precisely an artificial and "arbitrary" one, the result of an institution which links together two different natures. Thus, the paradoxical institution of linguistic signification turns out to be the theoretical experimentation which leads to the comprehension of the non natural, yet metaphysically constituted, unity of mind and body in man.

[fr] En prenant appui sur des textes de Descartes et de philosophes post-cartésiens comme Géraud de Cordemoy, ou encore des théoriciens de Port-Royal, tels Lancelot, Arnauld et Nicole, nous nous intéressons au statut double et paradoxal que revêt la parole dans la philosophie classique, au moment où se construit la question de l'union psychophysique et où sont proposées diverses " réponses " à cette question, dans la perspective d'une conceptualisation nouvelle d'une identité humaine rendue problématique. Le paradoxe tient au fait que l'activité de langage est d'abord manifestation de la pensée, indice publiquement observable ou témoignage extérieur de l'existence d'un esprit à l'origine des actes linguistiques, conformément à la théorie cartésienne à ce sujet ; mais la parole dénote aussi, dans la philosophie même de Descartes, une faculté spécifiquement humaine, propre au " vrai homme ", en tant qu'il est indissolublement esprit et corps. Nous tentons de montrer que ce qui est en jeu dans les études brèves et éparses que Descartes consacre au langage, puis dans les développements ultérieurs de la Grammaire générale et raisonnée et de la Logique de Port-Royal, à travers la théorie du signe linguistique et de la signification, c'est la compréhension de la relation, nécessairement postulée et pourtant constamment renvoyée à l'ordre d'un lien contre-nature, et par là arbitraire, fruit d'une institution, entre la parole comme phénomène physique et la parole comme activité symbolique par excellence ; si bien que le prodige du phénomène humain du langage, comme expression publique des pensées, donne la mesure de l'énigme que constitue l'unité en l'homme du corps et de l'esprit.