The question which will now naturally arise, and which I am bound to answer, is, how have these views been formed? and what is the authority for them? And the answer I have to make will startle many minds when I say, that they have been gathered from two sources; first and chiefly from the state in which those spirits appear to be, and sometimes avow themselves to be, who, after quitting the earth, return to it and make themselves visible to the living; and, secondly, from the revelations of numerous somnambules of the highest order, which entirely conform in all cases, not only with the revelations of the dead, but with each other. I do not mean to imply, when I say this, that I consider the question finally settled as to whether somnambules are really clear-seers or only visionaries; nor that I have by any means established the fact that the dead do sometimes actually return; but I am obliged to beg the question for the moment, since, whether these sources be pure or impure, it is from them the information has been collected. It is true that these views are extremely conformable with those entertained by Plato and his school of philosophers, and also with those of the mystics of a later age; but the latter certainly, and the former probably, built up their systems on the same foundation; and I am very far from using the term _mystics_ in the opprobrious, or at least contemptuous, tone in which it has of late years been uttered in this country; for, although abounding in errors, as regarded the concrete, and although their want of an inductive _methodology_ led them constantly astray in the region of the real, they were sublime teachers in that of the ideal; and they seem to have been endowed with a wonderful insight into this veiled department of our nature.