In the domain of mathematics education, the term discourse seems to be these days on everybody’s lips. Traditionally regarded as only auxiliary to thinking, active mathematical communication it is nevertheless believed to enhance mathematical learning. In my research, I am going farther than that: I conceptualize mathematics as a special form of communication. By doing this, I promote mathematical discourse from the role of a mere instructional means to that of the object of learning. I also propose that learning mathematics is an interplay between two concomitant activities – that of mathematizing, that is, communicating about mathematical objects; and that of subjectifying (or identity building), that is, communicating about participants of mathematical discourse. To stress the unified vision of communication and cognition, I call this perspective commognitive. In the talk, I will explore the implications of the commognitive approach for research in mathematics education and for the practice of teaching and learning mathematics. Theoretical arguments will be supported with empirical examples coming from my recent classroom studies.