Plato's parable of the cave is a metaphor for ignorance and knowledge. Imagine, says Plato, a cave in which prisoners are chained in such a way that all they can see are shadows thrown on a wall in front of them. All they know of life are these shadows. They would think that these shadows were reality, having known nothing else. If one of them were freed, and allowed to emerge into the daylight, he would see things as they are, and realize how limited his vision was in the cave. He would be quite unwilling to return:
And when he remembered his old habitation, and the wisdom of the den and his fellow-prisoners, do you not suppose that he would felicitate himself on the change, and pity them?...you must not wonder that those who attain to this beatific vision are unwilling to descend to human affairs; for their souls are ever hastening into the upper world where they desire to dwell. (Republic VII, 516)
Yet to his fellow-prisoners, he would seem the fool, not they:
And if there were a contest, and he had to compete in measuring the shadows with the prisoners who had never moved out of the den, while his sight was still weak, and before his eyes had become steady...would he not be ridiculous? Men would say of him that up he went and down he came without his eyes; and that it was better not even to think of ascending. (Ibid, 517)
I suggest that the lethal text may not in fact destroy the mind, but rather cause it to move up to a higher level of consciousness, which would seem "weak" to the people left behind. He might have a direct apprehension of Plato's world of Ideal Forms. Instead of having been destroyed, such a person might simply have transcended the body and no longer have need of it. (Such a fate is implied in Macroscope.)
I further suggest that the person who enters cyberspace has, in a metaphorical sense, left the cave. She has entered an abstract dataspace-a world of Ideal Forms-and has no need of the physical body. Indeed, the person wearing a bodysuit and VR goggles seems vaguely ridiculous to anyone watching her twist and turn in response to no apparent stimulus. She is, in a literal sense, a visionary.