12)"It is impractible, however, to keep our sleep free from stimuli; they impinge upon the sleeper from all sides - like the germs of life which Mephistopheles complained - from without and from within and even from parts of his body which are quite unoticed in waking life. Thus sleep is disturbed; first one corner of the mind is shaken into wakefulness and then another; the mind functions for a brief moment with its awakened portion and is then glad to fall asleep once more. Dreams are a reaction to the disturbance of sleep brought about by a stimulus - a reaction, incidentally, which is quite superfluous.
But the description of dreaming - which, after all is said and done, remains a function of the mind - as a somatic process implies another meaning as well. It is intended to show that dreams are unworthy to rank as psychical processes. Dreaming has often been compared with 'the ten fingers of a man who knows nothing of music wondering over the keys of a piano' [Strümpell, 1877, 84;cf.p.222 below]; and this simile shows as well as anything the sort of opinion that is usually held of dreaming by representatives of the exact sciences. On this view a dream is something wholly and completely incapable of interpretation; for how could the ten fingers of an unmusical player produce a piece of music?"