Indeed, but we rarely think of it that way. When people today hear of oral historians that could speak memorized lineages that took days to recite in full, they are shocked to think humans have that sort of memory capacity because we've become so used to the idea of memory-keeping technology. At the same time we maintain a conceit that we are separate from our technologies in some esoteric way. I doubt many people think of their personal computer (or their written diary) as an extension of their brain/ soul/ self, even though it is.
I don't think I agree with that. Nor do I agree that 'we became cyborgs with the first reed pressed on a plank of mud.'
Written records aren't a form of memory, or "memory-keeping technology". They're a
substitute for memory, and for the sort of memory-training that allowed oral historians to perform the sorts of feats you describe.
Take me, for an example. Right now, as I type this message, I'm sitting in an office lined with books on a variety of topics--mostly history, but some philosophy and literature.
I have these books in my office partly because I have nowhere else to put them, but mostly because I need them at hand when I'm doing research, and when I'm writing lectures. I don't have the training necessary to remember more than a tiny fraction of the information contained therein.
Instead of trying to memorize the contents of these books, as ancient scholars did, I use my memory as an index file. Suppose I need information on, say, the 1892 cholera epidemic in Hamburg, Germany. In my long-term memory, there's a brief abstract of a book called
Death in Hamburg: Society and Politics in the Cholera Years by Richard Evans. This abstract includes this book's most important conclusions, along with some of its more interesting details, and finally, its location on my shelves--over there, second shelf, on the left.
But the book itself isn't full of 'memories'. Its full of writing--that is to say, its full of signs, in the form of marks on pieces of paper. If I need some detailed information from this book, I pull it down off the shelf, read the signs therein, and commit this information to short-term memory. Then, once the need has passed, the book goes back on the shelf, and the detailed information is forgotten.
That book is also not an extension of myself, in any meaningful sense. Physically, it's quite separate from my body, and there is very little correspondence between its contents and the contents of my mind. It's no more a form of cybernetics than the bus I'll be riding home in the evening, or the microwave I'll be using to warm my dinner. (Insert bachelor joke here) Anything I can leave behind in my office overnight just isn't a part of my 'self'. It is other.
I think that, by defining cybernetics so broadly, you're both essentially inflating this term to the point that it lacks any distinctive meaning, and using it as a synonym for "technology."
After all, the distinctive feature of cybernetic technology (as most people understand that term) is that you
can't leave it at the office--or even take it off, the way you can with clothes or eyeglasses--or take it out, the way you can with dentures and contact lenses.
It is a part of you, and would require surgery to remove, like any other body part.
To return to Gibson: what made Molly a cyborg was her retractable razors and the mirrored lenses she had grafted over her eyes. It is this process of
grafting, this creation of a hybrid biological-mechanical organism, that defines a cyborg.
