But they are only the materials, they do not
suffice to produce them.

They do not suffice to produce them, because they are vague and
indeterminate. To speak only of those that play the principal role, the
changing colors and forms, which deploy before us when our eyes are
closed, never have well-defined contours. Here are black lines upon a
white background. They may represent to the dreamer the page of a book,
or the facade of a new house with dark blinds, or any number of other
things. Who will choose? What is the form that will imprint its decision
upon the indecision of this material? This form is our memory.

Let us note first that the dream in general creates nothing. Doubtless
there may be cited some examples of artistic, literary and scientific
production in dreams. I will recall only the well-known anecdote told of
Tartini, a violinist-composer of the eighteenth century. As he was
trying to compose a sonata and the muse remained recalcitrant, he went
to sleep and he saw in a dream the devil, who seized his violin and
played with master hand the desired sonata. Tartini wrote it out from
memory when he woke. It has come to us under the name of "The Devil's
Sonata." But it is very difficult, in regard to such old cases, to
distinguish between history and legend. We should have auto-observations
of certain authenticity. Now I have not been able to find anything more
than that of the contemporary English novelist, Stevenson. In a very
curious essay entitled "A Chapter on Dreams," this author, who is
endowed with a rare talent for analysis, explains to us how the most
original of his stories have been composed or at least sketched in
dreams. But read the chapter carefully. You will see that at a certain
time in his life Stevenson had come to be in an habitual psychical state
where it was very hard for him to say whether he was sleeping or waking.
That appears to me to be the truth. When the mind creates, I would say
when it is capable of giving the effort of organization and synthesis
which is necessary to triumph over a certain difficulty, to solve a
problem, to produce a living work of the imagination, we are not really
asleep, or at least that part of ourselves which labors is not the same
as that which sleeps. We cannot say, then, that it is a dream. In sleep,
properly speaking, in sleep which absorbs our whole personality, it is
memories and only memories which weave the web of our dreams. But often
we do no