Associative indexing, the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another. This is the essential feature of the Memex. The process of tying two items together is the important thing.
Vannevar BushThe question of whether a device will come into being depends upon three things: first, whether there is a practical use for it that warrants its development and manufacturing costs; second, whether the laws of physics applying to the elements available for its design allow the attainment of the needed ranges, sensitivities, or the like; and third, whether the pertinent art of manufacture has advanced sufficiently to allow a useful embodiment to be built successfully.
Vannevar BushScience has a simple faith, which transcends utility. Nearly all men of science, all men of learning for that matter, and men of simple ways too, have it in some form and in some degree. It is the faith that it is the privilege of man to learn to understand, and that this is his mission. If we abandon that mission under stress we shall abandon it forever, for stress will not cease. Knowledge for the sake of understanding, not merely to prevail, that is the essence of our being. None can define its limits, or set its ultimate boundaries.
Vannevar Bush