The phenomena of dreaming has exercised the ingenuity of mankind in all ages, and various have been the theories invented to account for it. Epicurus fancied that "an infinite number of subtle images, some flowing from bodies, some formed of their own accord, and others made up of different things variously combined, were continually moving up and down in the air about us; and that those images, being of extreme fineness, penetrate our bodies, and, striking upon the mind, give rise to that mode of perception which we call Imagination, and to which he refers the origin, both of our waking thoughts and of our dreams.

Aristotle seems to think "that every object of outward sense makes, upon the human soul, or upon some other part of our frame, a certain impression, which remains for some time after the object that made it is gone; and which, being afterwards recognised by the mind in sleep, gives rise to those visions that then present themselves."

Locke says, "The dreams of sleeping men are all made up of the looking man's ideas;" but that this is not the case the experience of hundreds will prove, for there is scarcely a person now in existence, who, if appealed to whether they have not dreamed of places and persons they have never even thought of, and of events of which they have had no manner or kind of apprehension, but would answer in the affirmative. To say nothing of the vast multitude of ominous and prophetic dreams that the history of almost every family, and certainly of every generation, both in past and present times, will furnish.

Other persons adduce the phenomena of dreaming as a proof of the immortality of the soul, grounding their opinions upon the numerous instances recorded in "Holy Writ;" where prophetic inspirations and forewarnings were derived from these nocturnal visions. Mr. Baxter, the celebrated divine, goes so far in this subject as to ascribe "all our dreams to separate spirits, having access to our minds and furnishing us with ideas while we sleep."

The celebrated Dr. Young hath poetically summed up the cases of common dreams, in his usual sprightly, yet solemn manner, thus:

"Tit past conjecture; all things rise in proof: While o'er my limbs sleep's soft dominion spreads, What though my soul fantastic measures trod O'er fairy fields; or mourn'd along the gloom Of pathless woods; or, down the craggy steep Hurl'd headlong, swam with pain the mantled pool; Or scaled the cliff; or danc'd on hollow winds With antic shapes, wild natives of the brain; Her ceaseless flight, though devious, speaks her nature Cf subtler essence than the trodden clod; Active, aerial, tow'ring unconfin'd, Unfetter'd with her gross companions' fall. E'en silent night proclaims my soul immortal! E'en silent night proclaims eternal day! For human weal. Heaven husbands all events; Dull sleep instructs, nor sport vain dreams in vain!"

The accomplished Addison, in one of his Spectators, considers our common dreams as giving us some idea of the great excellency of a human soul, and some intimation of its tradependencies on matter. The heads of what he observes upon them, are as follows: - First, "our dreams are great instances of that activity which is natural to the human sou], and which it is not in the power of sleep to deaden or abate. Secondly, "Dreams are an instance of that agility and perfection which are natural to the faculties of the mind, when they are disengaged from the body." Thirdly, "the passions affect the mind with greater strength when we are asleep, than when we are awake." Fourthly, what gives us a very high idea of the nature of the soul, in regard to what passes in dreams, is that innumerable multitude and variety of ideas which then arise in her." Fifthly, "the next property of the soul is, that wonderful power of producing her own company on these occasions." Sixthly, "the last property of the soul I would mention, is its power of divining in dreams." See Spectator, 487, where all these heads are enlarged upon.

The excellent Bishop Bull delivers the following sentiments relative to dreams, in his discourse on the office of the holy angels. "It is true, indeed," says this pious man, "the good angels do not now ordinarily appear in visible forms, or speak by audible voices to men, as in ancient times they did. After God had once spoken unto men by his own son, manifested in the flesh, and by him fully revealed his will to the world, and confirmed that revelation by a long succession of unquestionable miracles, there was no such need of angelic appearances, for the instruction, confirmation, and consolation of the faithful. The succeeding ages do indeed afford us very credible relations of some such apparitions now and then; but ordinarily, I say, the government of angels over us is now administered in a secret and invisible manner. Hence too, too many have been inclined either flatly to deny, or at least to call in question, the truth of the doctrine we are now upon. But they have souls very much immersed in flesh, who can apprehend nothing but what touches and affects their senses; and they that follow this gross and sensual way of procedure, must at last necessarily fall into down, right Epicurism, to deny all particular providence of God over the sons of men, and to ascribe all events to those causes that are next to them.

"But, besides, although the ministry of angels be now for the most part invisible, yet to the observant it is not altogether indiscernible.

"We may trace the footsteps of this secret providence over us in many instances, of which I shall note a few. How often may we have observed strong, lasting, and irresistible impulses upon our minds, to do certain things, we can scarce for the present tell why or wherefore; the reason and good success of which we afterwards plainly see. So, on the contrary, there are oftentimes sudden and unexpected accidents, as we call them, cast in our way to divert us from certain enterprises we are just ready to engage in, the ill consequences whereof we do afterwards, but not till then, apprehend. Again, quantum est in subitis casibus ingenium! How strange many times are our present thoughts and suggestions in sudden and surprising dangers! We then, upon the spot, resolve and determine as well as if we had a long time deliberated, and taken the best advice and counsel; and we ourselves afterwards wonder how such thoughts came into our minds. Hither, also, we may refer that lucky conspiracy of circumstances which we sometimes experience in our affairs and business, otherwise of great difficulty: when we light upon the nick of opportunity; when the persons whose counsel or assistance we most need strangely occur, and all things things fall out according to our desire, but beyond our expectation. What strange ominous forebodings and fears do many times on a sudden seize upon men of certain approaching evils, whereof at present there is no visible appearance! And have we not had some unquestionable instances of men not inclined to melancholy, strongly and unalterably persuaded of the near approach of their death, so as to be able punctually to tell the very day of it, when they have been in good health, and neither themselves nor their friends could discern any present natural cause for such a persuasion, and yet the event hath proved that they were not mistaken. And, although I am no deter on dreams, yet, I verily believe, that some dreams are monitory above the power of fancy, and impressed on us by some superior influence; for of such dreams we have plain and undeniable instances in history, both sacred and profane, and in our own age and observation. Nor shall I so value the laughter of sceptics, and the scoffs of the epicureans, as to be ashamed to profess that I myself have had some convincing experiments of such impressions. Now, it is no enthusiasm, but the best account that can be given of them, to ascribe these things to the ministry of those invisible instruments of God's providence, that guide and govern our affairs and concerns, - namely, the angels of God."