A thorough and philosophical treatise on the subject of evidence is, in view of these considerations, much needed.  The liability all men are under to confound the fictions of their imaginations with the realities of actual observation is not understood with sufficient clearness by the community; and, so long as it is not understood and regarded, serious mistakes and inconveniences will be apt to occur in seasons of general excitement.  We are still disposed to attribute more importance than we ought to strong convictions, without stopping to inquire whether they may not be in reality delusions of the understanding.  The cause of truth demands a more thorough examination of this whole subject.  The visions that appeared before the mind of the celebrated Colonel Gardiner are still regarded by the generality of pious people as evidence of miraculous interposition, while, just so far as they are evidence to that point, so far is the authority of Christianity overthrown; for it is a fact, that Lord Herbert of Cherbury believed with equal sincerity and confidence that he had been vouchsafed a similar vision sanctioning his labors, when about to publish what has been pronounced one of the most powerful attacks ever made upon our religion.  It is dangerous to advance arguments in favor of any cause which may be founded upon nothing better than the reveries of an ardent imagination!

The phenomena of dreams, of the exercises and convictions which occupy the mind, while the avenues of the senses are closed, and the soul is more or less extricated from its connection with the body, particularly in the peculiar conditions of partial slumber, are among the deep mysteries of human experience.  The writers on mental philosophy have not given them the attention they deserve.

The testimony in these trials is particularly valuable as showing the power of the imagination to completely deceive and utterly falsify the senses of sober persons, when wide awake and in broad daylight.  The following deposition was given in Court under oath.  The parties testifying were of unquestionable respectability.  The man was probably a brother of James Bayley, the first minister of the Salem Village parish.

“THE DEPOSITION OF JOSEPH BAYLEY, aged forty-four years.—­Testifieth and saith, that, on the twenty-fifth day of May last, myself and my wife being bound to Boston, on the road, when I came in sight of the house where John Procter did live, there was a very hard blow struck on my breast, which caused great pain in my stomach and amazement in my head, but did see no person near me, only my wife behind me on the same horse; and, when I came against said Procter’s house, according to my understanding, I did see John Procter and his wife at said house.  Procter himself looked out of the window, and his wife did stand just without the door.  I told my wife of it; and she did look that way, and could see nothing but a little maid at the door.