The dreams in which we seem to ourselves to be suffering from the difficulty or impossibility of movement thus constitute a special class. Jewell would apply to them the term 'nightmare,' which he regards as 'characterised by inability to move or speak.' When, in dreams, we become conscious of difficult movement, it has frequently, and perhaps usually, happened that the motor channels are not entirely closed, the sensory channels unusually open, and very frequently, though not necessarily, this is associated with the approach of awakening. I dreamed that I was walking with a friend, that we quarrelled, and that thereupon I crossed the road, and walked on ahead of him. These actions seemed entirely effortless. Gradually, however, I became conscious of immense and ineffectual effort in keeping in front, and slowly began to experience, as I awakened, a feeling of lassitude in my actual and motionless limbs. In the process of awakening, I take it, the increased, but still defective, efflux of sensation from the legs, conveying the message of their real position, entered into conflict with the dream imagery, and produced a struggle in consciousness. It is by no means necessary to assume that there was a complete absence of sensory impressions from the legs during the earlier part of the dream; on the contrary, it is probable that the feeling of lassitude was itself the cause of the dream, the idea of walking being a theory to account for the lassitude; this seems more probable than that the actual lassitude was caused by the mental exertion in the dream.
In a dream which a friend tells me he has often had, and always finds painful, he imagines he is climbing a mountain, and at last reaches a point at which, notwithstanding all his efforts, further progress is impossible. It seems probable that this dream is also an example of the conflict due to the process of awakening. In this case, however, the solution is complicated by the fact that in earlier life the dreamer had really once found himself in the situation he now only experiences in dreams.
It is sometimes possible to prove, through the evidence of a witness, that in our dreams of movements executed with difficulty, we are really sufficiently awake on the motor side to be making actual movements, though these actual movements may only very roughly correspond to the movements we imagine we are trying to make. Very frequently, no doubt, dreams of difficult movement co-exist with, or are caused by, some degree of actual movement. In some such cases, indeed, the slight and imperfect actual movement may, in dream consciousness, be a complete and adequate movement. In these cases the imperfect sensory messages are not, it seems, sufficiently precise to reveal to sleeping consciousness the imperfection of the motor impulses.