In attempting to theorize the specific impact of hypertext technology on our understanding of writing, we might usefully recall Freud's brief essay, "A Note Upon the 'Mystic Writing-Pad'" (1925). Mystic writing pads are children's toys consisting of a thin sheet of clear plastic which covers a thick waxen board. The user can write on it with any pointed instrument, even a fingernail. The tip of the stylus presses through the sheet of plastic and makes a faint indentation in the wax below which appears as a dark trace through the plastic. When the plastic sheet is lifted away from the surface of the waxen tablet beneath, the dark traces disappear; the pad is clean again, like a blackboard just wiped off. This is its "mystic" or magical quality.
For Freud, all means of mechanically supplementing the memory suffered from one of two drawbacks. Permanent means of recording, like paper, can only be written on once--they quickly become filled and need to be further supplemented. The alternative (eg: a chalk board) is infinitely receptive, but only if one erases the previous inscriptions. The Mystic Writing Pad, however, represented an admittedly imperfect but illuminating example of how the psyche itself records material. Like the chalk board, it can record an infinite amount of material while always remaining "new." But, like the piece of paper, this material leaves a faint, but perceptible trace on the waxen surface below, a trace which can be seen if one were to lift up the sheet of plastic and examine the wax surface. This, for Freud, is analogous to the way the psychic system which received sense impression from the outside world remains unmarked by those impressions which pass through it to a deeper layer where they are recorded as unconscious memory. Thus, "the appearance and disappearance of the writing" is similar to "the flickering-up and passing-away of consciousness in the process of perception" (SE XIX:230).
Freud's somewhat off-hand analogy of the way which the perceptive conscious passes experience through to the unconscious to a child's toy has had a curious career. In "Freud and the Scene of Writing," Derrida notes the father of psycho-analysis's dependence on metaphors of writing to describe psychological processes and concludes that this is no metaphor, that perception really is a kind of writing machine like the Mystic Writing Pad. Derrida in particular notes the fact that the marks on the pad are not visible due to the stylus leaving a deposit on the sheet of plastic (in the manner of a pen, ink and paper). The marks only become visible because of the contact the wax has on the reverse side of the sheet of plastic. This is also the case in perception. None of us, Derrida claims, apprehend the world directly, but only retrospectively; our sense of that which is beyond ourselves is the product of previous memories, previous writings. "Writing," says Derrida, "supplements perception before perception even appears to itself" (Writing and Difference 224).
The Mystic Writing Pad, then, is a model of the primacy of writing, of the way in which we can only ever experience the world, as it were, after the fact, that is, through the traces of previous experiences and through the signifiers which are in effect the condition of being.
Hypertext might be described as a hyper-Mystic Writing Pad; it is both infinitely receptive to new experience and capable of potentially infinite (at least to the limit of the computer's memory) retention. Its "magic" arises from its ability to reactivate any trace unaltered from when it was first recorded. More particularly, hypertext allows writing to become a physical force which, like that which enters the unconscious through perception, creates paths and webs which determine the structure of all subsequent experiences. Here words have presence only in so much as they are (literally) illumined from behind, just as we attain identity only retroactively, through a kind of perpetual process of catching up to ourselves.
Thus experience in hypertext must always reproduce the very act of writing itself; as a physical act which leaves, in the form of new links, anchors and nodes, the indelible traces of our passing. In reading a hypertext, our sense of immediacy, of a text "unfolding" before our eyes for "the first time," is underscored by the presence of other readings and other authors, other versions of ourselves that throw into question the very concept of being as a unified, coherent and stable whole existing in the plenitude of the present. In hypertext, consciousness is displaced from the act of apprehension, from the act of reading, to experience of having been written.