Human beings have many different and incompatible modes of speaking.
It is impossible to form a unity of these modes of enunciation or of the person who speaks. Furthermore, we cannot refer or appeal to subjectivity as the source of meaning in the act of speaking ! The analysis of statements operates therefore without reference to a cogito statements.
With Foucault, we know also that subjectivity and consciousness are constituted on the basis of complex power-knowledge relations.