Alain Badiou occupies the place of the teacher whose primary responsibility rests on the transmission of tradition. The transmission occurs as a consequence of the teacher, the master, the professor, or, as it happens, the old man. Clearly, Badiou occupies all of these roles. However, what concerns us today is that he is an old man and that the old man is the man who is approaching death. In fact, he does not shy away from this designation. Rather, he acknowledges this point with a smile: “Do not say that I am really a young man because it is not true. I know that I am seventy-five years old.” Our teacher is fully aware that he is at the “beginning of the last straight line of life.” The possibility of the death of the old man necessitates a thinking about the preservation of the transmission of the future. The Subject of Change is a sustained engagement with the concept of change. The questions it asks include: what is a change?, what is a true change?, is change better than immobility?, what are the different types of change?, and, finally, what is the localization of change?