appeared and given me the explanation. Maury publishes tales in which
a forgotten fact was revealed to him in a dream from the lips of a
dream-character (Le Sommeil et les Reves, pp. 142-143. The curious
may also consult, on all these things, The Philosophy of Mysticism, by
Karl du Prel, translated by Mr. Massey. The Assyrian Priest is in
Proceedings, S.P.R., vol. xii., p. 14).

On the same plane as the dreams which we have been examining is the
waking sensation of the deja vu.

"I have been here before,
But when or how I cannot tell."

Most of us know this feeling, all the circumstances in which we find
ourselves have already occurred, we have a prophecy of what will
happen next "on the tip of our tongues" (like a half-remembered name),
and then the impression vanishes. Scott complains of suffering
through a whole dinner-party from this sensation, but he had written
"copy" for fifty printed pages on that day, and his brain was breaking
down. Of course psychology has explanations. The scene _may_ have
really occurred before, or may be the result of a malady of
perception, or one hemisphere of the brain not working in absolute
simultaneousness with the other may produce a double impression, the
first being followed by the second, so that we really have had two
successive impressions, of which one seems much more remote in time
than it really was. Or we may have dreamed something like the scene
and forgotten the dream, or we may actually, in some not understood
manner, have had a "prevision" of what is now actual, as when Shelley
almost fainted on coming to a place near Oxford which he had beheld in
a dream.