“Multiple personality, perhaps,” says some one. “But does that account for the stereoscopic process of which you speak, that makes two sub-personalities speak from a double head, that as it were prints two pictures on the same photographic plate?” The objector is thereupon referred to the dream-machinery on which poetry appears to be founded. He will acknowledge that in dreams the characters are always changing in a most sudden and baffling manner. He will remember for example that in “Alice in Wonderland,” which is founded on dream-material, the Duchess’ baby is represented as turning into a pig; in “Alice through the Looking Glass” the White Queen becomes an old sheep. That is a commonplace of dreams.

When there is a thought-connection of similarity or contrast between two concepts, the second is printed over the first on the mental photographic plate so rapidly that you hardly know at any given moment whether it is a pig or a baby you are addressing. “You quite make me giddy,” said Alice to the Cheshire Cat who was performing similar evolutions. One image starts a sentence, another image succeeds and finishes it, almost, but the first reappears and has the last word. The result is poetry—or nonsense. With music much the same happens; I believe that those wonderful bursts of music heard in sleep are impossible to reproduce in a waking state largely because they consist of a number of melodies of different times and keys imposed on one another.