and I was close to
plagiarism. Indeed, if a history of plagiarism could be written, it
would probably abound in just such stories. I had read the article
containing this sentence only once, about three years before, and had
never quoted it or consciously thought of it. It had lain buried for
three years, only to come forth as an original idea of my own. Who
knows how many times we all do just this thing without catching
ourselves in the trick?

=Back-Door Memories.= There are other kinds of memories which hide in
the subconscious, memories of experiences which have not come in by
the front door, but have entered the mind during special states, such
as sleep, delirium, intoxication, or hypnosis. What is known as
post-hypnotic suggestion is the functioning of a suggestion received
during hypnosis and emerging later as an impulse without being
recognized as a memory. A man in a hypnotic state is told that at five
o'clock he will take off his clothes and go to bed, without
remembering that such a suggestion has been given him. He awakens with
no recollection of the suggestion, but at five o'clock he suddenly
feels impelled to go to bed, even though his unreasonable desire puts
him into a highly embarrassing position. The suggestion, to be thus
effective, must have been conserved somewhere in his mind outside of
consciousness.

Suggestions that enter the mind during the normal sleep are also
recorded,--a fact that carries a warning to people who are in the
habit of talking of all sorts of matters while in the room with
sleeping children. I have sometimes suggested to sleeping patients
that on waking they will remember and tell me the cause of their
symptoms. The following example shows not only the conservation of
impressions gained in sleep, but also the sway of forgotten ideas of
childhood, still strong in mature years. This young woman, a trained
nurse, with many marked symptoms of hysteria, had been asked casually
to bring a book from the Public Library. She cried out in
consternation, "Oh, no, I am afraid!" After a good deal of urging she
finally brought the book, although at the cost of considerable effort.
Later, while she was taking a nap, I said to her, "You will not
remember that I have talked to you. You will stay asleep while I am
talking and while you are asleep there will come to your mind the
reasons why you are afraid to go to the Public Library. When you
waken, you will tell me all about it." Upon awakeni