If left to himself he will probably go through routine actions well enough.

But any one who understands his condition can make him act absurdly.
In the same way when we dream we draw absurd inferences by association.
The feeling of discomfort due to slight indigestion produces a belief that we are about to speak to a large audience and have mislaid our notes, or are walking along the Brighton Parade in a night-shirt.

Even when men are awake, those parts of their mind to which for the moment they are not giving full attention are apt to draw equally unfounded inferences.

A conjurer who succeeds in keeping the attention of his audience concentrated on the observation of what he is doing with his right hand can make them draw irrational conclusions from the movements of his left hand.

People in a state of strong religious emotion sometimes become conscious of a throbbing sound in their ears, due to the increased force of their circulation.