In minor matters I have aimed above all things at clearness and readiness in reference. The division of the book into sections, with Appendices bearing the same numbers, will, it is hoped, facilitate the use both of syllabus and of references in general. I have even risked the appearance of pedantry in adding a glossary. Where many unfamiliar facts and ideas have to be dealt with, time is saved in the end if the writer explains precisely what his terms mean. * * * * * F. W. H. MYERS. GLOSSARY NOTE.--The words and phrases here included fall under three main heads:-- (1) Words common only in philosophical or medical use. (2) Words or phrases used in psychical research with some special significance. (3) A few words, distinguished by an asterisk, for which the author is himself responsible. _Aboulia._--Loss of power of willing. _After-image._--A retinal picture of an object seen after removing the gaze from the object. _Agent._--The person who seems to initiate a telepathic transmission. _Agraphia._--Lack of power to write words. _Alexia_ or _Word-blindness_.--Lack of power to understand words written. _Anæsthesia_, or the loss of sensation generally, must be distinguished from _analgesia_, or the loss of the sense of pain alone. _Analgesia._--Insensibility to pain. _Aphasia._--Incapacity of coherent utterance, not caused by structural impairment of the vocal organs, but by lesion of the cerebral centres for speech. _Aphonia._--Incapacity of uttering sounds. _Automatic._--Used of mental images arising and movements made without the initiation, and generally without the concurrence, of conscious thought and will. _Sensory automatism_ will thus include visual and auditory hallucinations. _Motor automatism_ will include messages written and words uttered without intention (automatic script, trance-utterance, etc.). _Automnesia._--Spontaneous revival of memories of an earlier condition of life. _Autoscope._--Any instrument which reveals a subliminal motor impulse or sensory impression, _e.g._, a divining rod, a tilting table, or a planchette. _Bilocation._--The sensation of being in two different places at once, namely where one's organism is, and in a place distant from it. _Catalepsy._--"An intermittent neurosis producing inability to change the position of a limb, while another person can place the muscles in a state of flexion or contraction as he will." (Tuke's _Dictionary of Psychological Medicine_.) _Centre of Consciousness._--The place where a percipient imagines himself to be. The point of view from which he seems to himself to be surveying some phantasmal scene. _Chromatism._--See _Secondary Sensations_. _Clair-audience._--The sensation of hearing an internal (but in some way veridical) voice. _Clairvoyance_ (_Lucidité_).--The faculty or act of perceiving, as though visually, with some coincidental truth, some distant scene.