PREFACE 



Recent researches in the ethereal realms of Mysticism, 

 Metaphysics,and transcendental Anthropology have proved 

 beyond a doubt the existence of a great number of appa- 

 rently mysterious and occult facts, whose causes cannot 

 be explained by a science whose means for investigation 

 are limited by the imperfections of sensual perception, 

 and whose researches must necessarily come to a stop 

 where physical instruments cease to be of any service. 

 Invisible things cannot be seen, neither can that which is 

 imponderable be weighed with scales; but invisible and 

 imponderable things, such as the cosmic ether, the light- 

 producing power of the sun, the vital power of plants and 

 animals, thought, memory, imagination, will, psychological 

 influences affecting the state of the mind or producing a 

 sudden change of feeling, and other things too numerous 

 to mention, are nevertheless facts, and exist in spite of 

 the incapacity of teachers of anatomy or chemistry to 

 explain them. If a reasonable sceptic says that such 

 things do not exist, he can only mean to say that they 

 do not exist relatively to his knowledge ; because, to deny 

 the possibility of the existence of anything of which we 

 know nothing would imply that we imagined ourselves 

 to be in possession of all the knowledge that exists in the 

 world, and believed that nothing could exist of which we 

 did not know. A person who peremptorily denies the 



