To this cause, then, may many of the reported phenomena of dream be assigned. It would be beyond the scope of this monograph to treat at any length of the manifold phenomena of Somnambulism, but some of them will certainly explain cases of dream apparently not to be accounted for, as all facts and phenomena may be, if rightly investigated, by reference to natural causes, without invoking the assistance of the supernatural. Somnambulism proves the presence of two abnormal mental conditions, namely, supersensuous perception and mental sympathy. The former is the name given to a faculty the mind has, under certain conditions, of perception beyond the range of the senses (whatever the _modus operandi_ may be). The other refers to a special form of sympathy of thoughts and emotions of one sensitive mind with other minds having a certain relationship with it. Many of the authentic cases of cognizance of the distant in dream may be thus accounted for. The sleeper has lapsed into somnambulism, is then, in fact, a somnambulist and not a dreamer. Possessing the abnormal development of the perceptive sense which is so familiar a fact in natural somnambulism, the mind has perceptions beyond the range of the senses and is susceptible of sympathies with other minds which the bodily senses cannot convey. That such mental conditions exist is proved conclusively by the numberless cases of natural somnambulism recorded in the medical journals of all countries and which are indeed familiar to every reader because of their frequent occurrence in common life.