"That the media influence bodies through emergence and immersion, on that point we both agree. However, I don't believe in the old thesis that thus the media are prostheses of the body, which amounts to saying, in the beginning was the body, then came the glasses, then suddenly television, and from the television, the computer. The mythology is that everything frees itself from the body, dissolves and submerges in it again, in the sense of emergence and immersion, virtual reality, cinemascope, and hallucination. Your theory may be true for some of the entertainment media, but I think to be able to describe a general media history, it would be better to work, like Luhmann, systematically from the independent histories of the technological media. The media don't emerge from the human body, rather you have, for example, the book, and the military generals in considering how they can subvert the book or the written word, come up with the telegraph, namely, the telegraph wire; and then to offset the military telegraph, they come up with the wireless radio, which Hitler builds into his tanks. In England Alan Turing or Churchill ponder a way to beat Germany's radio war, and they arrive at the computer to crack the radio signals - and the German goose is cooked, that's the end of the war. A history like this doesn't need individual bodies or a subject that expands in and through the media - such a history can do without the subjective agency of a historical actor. Rather, I think, it's a reasonable hypothesis to say that the media, including books and the written word, develop independently from the body. Even then, if you want to, you can describe how, through advertising or commercial means, the media influence and separate bodies."
Griffin, Matthew, Susanne Herrmann, and Friedrich A. Kittler. "Technologies of Writing: Interview with Friedrich A. Kittler." New Literary History 27, no. 4 (1996): 731-42.