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. The intellectual feats just spoken of, unless, indeed, they are referred to some mysterious unconscious mental operations, clearly involve a measure of volitional guidance. All who dream frequently are occasionally aware on awaking of having greatly exercised their attention on the images presented to them during sleep. I myself am often able to recall an effort to see beautiful objects, which threatened to disappear from my field of vision, or to catch faint receding tones of preternatural sweetness; and some dreamers allege that they are able to retain a recollection of the feeling of strain connected with such exercise of attention in sleep. The main function of this voluntary attention in dream-life is seen in the selection of those images which are to pass the threshold of clear consciousness. I have already spoken of a selective action brought about by the ruling emotion. In this case, the attention is held captive by the particular feeling of the moment. Also a selective process goes on in the case of the action of those associative dispositions just referred to. But in each of these cases the action of selective attention is comparatively involuntary, passive, and even unconscious, not having anything of the character of a conscious striving to compass some end. Besides this comparatively passive play of selective attention, there is an active play, in which there is a conscious wish to gain an end; in other words, the operation of a definite motive. This motive may be described as an intellectual impulse to connect and harmonize what is present to the mind. The voluntary kind of selection includes and transcends each of the involuntary kinds. It has as its result an imitation of that order which is brought about by what I have called the associative dispositions, only it consciously aims at this result. And it is a process controlled by a feeling, namely, the intellectual sentiment of consistency, which is not a mode of emotional excitement enthralling the will, but a calm motive, guiding the activities of attention. It thus bears somewhat the same relation to the emotional selection already spoken of, as dramatic creation bears to lyrical composition.