On the contrary, under certain circumstances we become still more fully aware of this apparent motion created by our inner activity when we are conscious of the interruptions between the various phases of movement.
We come to the consequences.

What is then the difference between seeing motion in the photoplay and seeing it on the real stage?
There on the stage where the actors move the eye really receives a continuous series.
Each position goes over into the next without any interruption.

The spectator receives everything from without and the whole movement which he sees is actually going on in the world of space without and accordingly in his eye.

But if he faces the film world, _the motion which he sees appears to be a true motion, and yet is created by his own mind_.

The afterimages of the successive pictures are not sufficient to produce a substitute for the continuous outer stimulation; the essential condition is rather the inner mental activity which unites the separate phases in the idea of connected action.