Now, if any shade of feeling becomes fixed and dominant in the mind, it will tend to control all the images of the time, allowing certain congruous ones to enter, and excluding others.[95] If, for example, a feeling of distress occupies the mind, distressing images will have the advantage in the struggle for existence which goes on in the world of mind as well as in that of matter.

We may say that attention, which is here wholly a passive process, is controlled by the emotion of the time, and bent in the direction of congruent or harmonious images.
Now, a ground-tone of feeling of a certain complexion, answering to the sum of sensations arising in connection with the different organic processes of the time, is a very frequent foundation of our dream-structure.

So frequent is it, indeed, that one might almost say there is no dream in which it is not one great determining factor.

The analysis of a very large number of dreams has convinced me that traces of this influence are discoverable in a great majority.
I will give a simple illustration of this lyrical type of dream.

A little girl of about four years and three-quarters went with her parents to Switzerland.