Deva, Orbs, fairies, Big foot, the universe is full of mysteries that we are here to uncover.

discusses the eternal mystery of the paranormal in The Unknown Guest:  

"When I speak of the present position of the mystery, I of course do not mean the mystery of life, its end and its beginnings, nor yet the great riddle of the universe which lies about us. In this sense, all is mystery, and, as I have said elsewhere, is likely always to remain so; nor is it probable that we shall ever touch any point of even the utmost borders of knowledge or certainty.

It is here a question of that which, in the midst of this
recognized and usual mystery, the familiar mystery of which we are almost oblivious, suddenly disturbs the regular course of our general ignorance. In themselves, these facts which strike us as supernatural are no more so than the others; possibly they are rarer, or, to be more accurate, less frequently or less easily observed. In any case, their deep-seated cause, while being probably neither more remote nor more difficult access, seem to lie hidden in an unknown region less often visited by our science, which after all is but a reassuring and conciliatory
espression of our ignorance".