[Footnote 79: The action of some drugs produces a state in this respect resembling that which prevails in dreams. 'Under the influence of a large dose of haschisch,' Professor Stout remarks (_Analytic Psychology_, vol. i. p. 14), 'I found myself totally unable to distinguish between what I actually did and saw, and what I merely thought about.' Not only are the motor and sensory activities relatively dormant, but the central activity is perfectly able, and content, to dispense with their services. 'Thought,' as Jastrow says (_Fact and Fable in Psychology_, p. 386), 'is but more or less successfully suppressed action.']
[Footnote 80: This seems to me to be the answer to the question, asked by Freud, (_Die Traumdeutung_, p. 227), why we do not always dream of inhibited movement. Freud considers that the idea of inhibited movement, when it occurs in dreams, has no relation to the actual condition of the dreamer's nervous system, but is simply an ideatory symbol of an erotic wish that is no longer capable of fulfilment. But it is certain that sleep is not always at the same depth and that the various nervous groups are not always equally asleep. A dream arising on the basis of partial and imperfect sleep can scarcely fail to lead to the attempt at actual movement and the more or less complete inhibition of that movement, presenting a struggle which is often visible to the onlooker, and is not purely ideatory.]
[Footnote 81: This explanation, based on the depth and kind of the sleep, is entirely distinct from the theory of Aliotta (_Il Pensiero e la Personalità nei Sogni_, 1905), who believes that dreamers differ according to their nervous type, the person of visual type assisting passively at the spectacle of his dreams, while the person of motor type takes actual part in them. I have no evidence of this, though I believe that dreams differ in accordance with the dreamer's personal type.]
[Footnote 82: Dugald Stewart argued that there is loss of control over the muscular system during sleep, and the body, therefore, is not subject to our command; volition is present but it cannot influence the limbs. Hammond argued, on the contrary, that Stewart was quite wrong; the reason why voluntary movements are not performed during sleep is, he said, that volition is suspended. 'We do not will our actions when we are asleep. We imagine that we do, and that is all' (_Treatise on Insanity_, p. 205). Dugald Stewart and Hammond, though their phraseology may have been too metaphysical, were, from the standpoint I have adopted, both maintaining tenable positions. In one type of dream, we imagine we easily achieve all sorts of difficult and complicated actions, but in reality we make no movement; the ease and rapidity with which the mental machine moves is due to the fact that it is ungeared, and is effecting no work at all. In the other type of dream we make violent but inadequate efforts at movement and only partially succeed; the machine is partially geared, in a state intermediate between deep sleep and the waking condition.]