In point of fact, the dreamer, not to speak of the somnambulist, is often conscious of voluntarily going through a series of actions.
This exercise of volition is shown unmistakably in the well-known instances of extraordinary intellectual achievements in dreams, as Condillac's composition of a part of his _Cours d'Etudes_.

No one would maintain that a result of this kind was possible in the total absence of intellectual action carefully directed by the will.

And something of this same control shows itself in all our more fully developed dreams.
One manifestation of this voluntary activity in sleep is to be found in those efforts of attention which not unfrequently occur.

I have remarked that, speaking roughly and in relation to the waking condition, the state of sleep is marked by a subjection of the powers of attention to the force of the mental images present to consciousness.

Yet something resembling an exercise of voluntary attention sometimes happens in sleep.