The real heart of the matter of selection, however, goes deeper
than a lag in the adoption of mechanisms by libraries, or a lack
of development of devices for their use. Our ineptitude in
getting at the record is largely caused by the artificiality of
systems of indexing. When data of any sort are placed in
storage, they are filed alphabetically or numerically, and
information is found (when it is) by tracing it down from
subclass to subclass. It can be in only one place, unless
duplicates are used; one has to have rules as to which path will
locate it, and the rules are cumbersome. Having found one
item, moreover, one has to emerge from the system and
re-enter on a new path.

The human mind does not work that way. It operates by
association. With one item in its grasp, it snaps instantly to the
next that is suggested by the association of thoughts, in
accordance with some intricate web of trails carried by the
cells of the brain. It has other characteristics, of course; trails
that are not frequently followed are prone to fade, items are not
fully permanent, memory is transitory. Yet the speed of action,
the intricacy of trails, the detail of mental pictures, is
awe-inspiring beyond all else in nature.

Man cannot hope fully to duplicate this mental process
artificially, but he certainly ought to be able to learn from it. In
minor ways he may even improve, for his records have relative
permanency. The first idea, however, to be drawn from the
analogy concerns selection. Selection by association, rather
than indexing, may yet be mechanized. One cannot hope thus
to equal the speed and flexibility with which the mind follows an
associative trail, but it should be possible to beat the mind
decisively in regard to the permanence and clarity of the items
resurrected from storage.

Consider a future device for individual use, which is a sort of
mechanized private file and library. It needs a name, and, to
coin one at random, "memex" will do. A memex is a device in
which an individual stores all his books, records, and
communications, and which is mechanized so that it may be
consulted with exceeding speed and flexibility. It is an enlarged
intimate supplement to his memory.

It consists of a desk, and while it can presumably be operated
from a distance, it is primarily the piece of furniture at which he
works. On the top are slanting translucent screens, on which
material can be projected for convenient reading. There is a
keyboard, and sets of buttons and levers. Otherwise it looks
like an ordinary desk.

In one end is the stored material. The matter of bulk is well
taken care of by improved microfilm. Only a small part of the
interior of the memex is devoted to storage, the rest to
mechanism. Yet if the user inserted 5000 pages of material a
day it would take him hundreds of years to fill the repository,
so he can be profligate and enter material freely.

Most of the memex contents are purchased on microfilm ready
for insertion. Books of all sorts, pictures, current periodicals,
newspapers, are thus obtained and dropped into place.
Business correspondence takes the same path. And there is
provision for direct entry. On the top of the memex is a
transparent platen. On this are placed longhand notes,
photographs, memoranda, all sorts of things. When one is in
place, the depression of a lever causes it to be photographed
onto the next blank space in a section of the memex film, dry
photography being employed.

There is, of course, provision for consultation of the record by
the usual scheme of indexing. If the user wishes to consult a
certain book, he taps its code on the keyboard, and the title
page of the book promptly appears before him, projected onto
one of his viewing positions. Frequently-used codes are
mnemonic, so that he seldom consults his code book; but when
he does, a single tap of a key projects it for his use. Moreover,
he has supplemental levers. On deflecting one of these levers to
the right he runs through the book before him, each page in turn
being projected at a speed which just allows a recognizing
glance at each. If he deflects it further to the right, he steps
through the book 10 pages at a time; still further at 100 pages
at a time. Deflection to the left gives him the same control
backwards.

A special button transfers him immediately to the first page of
the index. Any given book of his library can thus be called up
and consulted with far greater facility than if it were taken from
a shelf. As he has several projection positions, he can leave
one item in position while he calls up another. He can add
marginal notes and comments, taking advantage of one
possible type of dry photography, and it could even be
arranged so that he can do this by a stylus scheme, such as is
now employed in the telautograph seen in railroad waiting
rooms, just as though he had the physical page before him.

This article was originally published in the July 1945 issue of The Atlantic Monthly.