apprehensions, functions as a fundamental physical qualification of things in Spencer's 'law of evolution,' and doubtless passes with most readers for all right. Psychologists, studying our perceptions of movement, have unearthed experiences in which movement is felt in general but not ascribed correctly to the body that really moves. Thus in optical vertigo, caused by unconscious movements of our eyes, both we and the external universe appear to be in a whirl. When clouds float by the moon, it is as if both clouds and moon and we ourselves shared in the motion. In the extraordinary case of amnesia of the Rev. Mr. Hanna, published by Sidis and Goodhart in their important work on _Multiple Personality_, we read that when the patient first recovered consciousness and "noticed an attendant walk across the room, he identified the movement with that of his own. He did not yet discriminate between his own movements and those outside himself."[79] Such experiences point to a primitive stage of perception in which discriminations afterwards needful have not yet been made. A piece of experience of a determinate sort is there, but there at first as a 'pure' fact. Motion originally simply _is_; only later is it confined to this thing or to that. Something like this is true of every experience, however complex, at the moment of its actual presence. Let the reader arrest himself in the act of reading this article now. _Now_ this is a pure experience, a phenomenon, or datum, a mere _that_ or content of fact. _'Reading' simply is, is there_; and whether there for some one's consciousness, or there for physical nature, is a question not yet put. At the moment, it is there for neither; later we shall probably judge it to have been there for both. With the affectional experiences which we are considering, the relatively 'pure' condition lasts. In practical life no urgent need has yet arisen for deciding whether to treat them as rigorously mental or as rigorously physical facts. So they remain equivocal; and, as the world goes, their equivocality is one of their great conveniences.