Finally the Unconscious plays the part of supervisor over our physical processes. Digestion, assimilation, the circulation of the blood, the action of the lungs, the kidneys and all the vital organs are controlled by its agency. Our organism is not a clockwork machine which once wound up will run of itself. Its processes in all their complexity are supervised by mind. It is not the intellect, however, which does this work, but the Unconscious. The intellect still stands aghast before the problem of the human body, lost like Pascal in the profundities of analysis, each discovery only revealing new depths of mystery. But the Unconscious seems to be familiar with it in every detail.

It may be added that the Unconscious never sleeps; during the sleep of the conscious it seems to be more vigilant than during our waking hours.

In comparison with these, the powers of the conscious mind seem almost insignificant. Derived from the Unconscious during the process of evolution, the conscious is, as it were, the antechamber where the crude energies of the Unconscious are selected and adapted for action on the world outside us. In the past we have unduly exaggerated the importance of the conscious intellect. To claim for it the discoveries of civilisation is to confuse the instrument with the agent, to attribute sight to the field-glass instead of to the eye behind it. The value of the conscious mind must not be underrated, however. It is a machine of the greatest value, the seat of reason, the social instincts and moral concepts. But it is a machine and not the engine, nor yet the engineer. It provides neither material nor power. These are furnished by the Unconscious.

These two strata of mental life are in perpetual interaction one with the other. Just as everything conscious has its preliminary step in the Unconscious, so every conscious thought passes down into the lower stratum and there becomes an element in our being, partaking of the Unconscious energy, and playing its part in supervising and determining our mental and bodily states. If it is a healthful thought we are so much the better; if it is a diseased one we are so much the worse. It is this transformation of a thought into an element of our life that we call Autosuggestion. Since this is a normal part of the mind's action we shall have no difficulty in finding evidence of it in our daily experiences.

Walking down the street in a gloomy frame of mind you meet a buoyant, cheery acquaintance. The mere sight of his genial smile acts on you like a tonic, and when you have chatted with him for a few minutes your gloom has disappeared, giving place to cheerfulness and confidence. What has effected this change?—Nothing other than the idea in your own mind. As you watched his face, listened to his good-natured voice, noticed the play of his smile, your conscious mind was occupied by the idea of cheerfulness. This idea on being transferred to the Unconscious became a reality, so that without any logical grounds you became cheerful.

Few people, especially young people, are unacquainted with the effects produced by hearing or reading ghost-stories. You have spent the evening, let us say, at a friend's house, listening to terrifying tales of apparitions. At a late hour you leave the fireside circle to make your way home. The states of fear imaged before your mind have realised themselves in your Unconscious. You tread gingerly in the dark places, hurry past the churchyard and feel a distinct relief when the lights of home come into view. It is the old road you have so often traversed with perfect equanimity, but its cheerful associations are overlooked and the commonest objects tinged with the colour of your subjective states. Autosuggestion cannot change a post into a spectre, but if you are very impressionable it will so distort your sensory impressions that common sounds seem charged with supernatural significance and every-day objects take on terrifying shapes.

In each of the above examples the idea of a mental state—cheerfulness or fear—was presented to the mind. The idea on reaching the Unconscious became a reality; that is to say, you actually became cheerful or frightened.

The same process is much easier to recognise where the resultant is not a mental but a bodily state.

One often meets people who take a delight in describing with a wealth of detail the disorders with which they or their friends are afflicted. A sensitive person is condemned by social usage to listen to a harrowing account of some grave malady. As detail succeeds detail the listener feels a chilly discomfort stealing over him. He turns pale, breaks into a cold perspiration, and is aware of an unpleasant sensation at the pit of the stomach. Sometimes, generally where the listener is a child, actual vomiting or a fainting fit may ensue. These effects are undeniably physical; to produce them the organic processes must have been sensibly disturbed. Yet their cause lies entirely in the idea of illness, which, ruthlessly impressed upon the mind, realises itself in the Unconscious.

This effect may be so precise as to reproduce the actual symptoms of the disease described. Medical students engaged in the study of some particular malady frequently develop its characteristic symptoms.