Question Three
On dreams and the apparitions of dreams, containing six questions
Little Question One of Question Three
On the causes of dreams and their definition
It is asked what a dream is, and also whence dreams, or the phantastic apparitions of dreams, are caused.
To this it is answered as follows: a dream, according to the Philosopher in Book II of On Sleep and Waking, is a phantasm made by the motion of images from a sensible likeness in one sleeping insofar as he sleeps.
A dream, or a phantasm of this kind, can have its origin from several things, and thus dreams can have several causes. For in general the cause of dreams is twofold: namely, interior and exterior.
The first, interior cause is also twofold. For the first is mental or spiritual: namely, a thought or affection, insofar as those things occur to a human being’s phantasy while he sleeps around which his thought and affection lingered while he was awake.
The second interior cause of dreams is a corporeal disposition. For from an interior disposition of the body, some motion conformable to such a disposition is formed in the phantasy. Thus it occurs to a human being in whom cold humors abound that he is in water or snow. And for this reason physicians say that attention must be given to dreams in order to cognize the interior dispositions of the body.
The second cause of dreams is exterior, and this is twofold. The first is spiritual. This is sometimes from God, who through the ministry of angels reveals certain things to human beings in dreams, as was said above. Sometimes, however, through the operation of demons certain phantasms appear to those sleeping; from these, certain future things are sometimes revealed to those who have illicit pacts with the demons, as will be said below in the Third Decade.
The second exterior cause is corporeal: namely, a change of the imagination or phantasy, insofar as the imagination or phantasy of one sleeping is changed either by the surrounding air or, as astronomers say, by an impression of a celestial body, so that certain phantasms conformable to the disposition of the celestial bodies appear to the sleeper.
For understanding this, it must be noted that astronomers say that the heaven, or celestial bodies, acts upon dreams per se. For they very often say that human beings’ dreams are conformable to the dispositions and configurations of the stars—so much so that, if the disposition of the heaven at the hour of the dream is known, an astrologer can state concerning what deed the dream occurred.
They also say that, just as when choler abounds in a human being, that human being dreams about hot and red things, and when phlegm abounds, about cold and watery things, as natural effects caused by a natural cause, so likewise the heaven can impart a cognition of the effects which it virtually contains, and consequently can make an impression upon sleepers per se so that they dream.
To these persons it is answered that, although the heaven can do something toward dreams, this is nevertheless not per se: namely, through the impression of a new species or of an interior cognition, whether sensual or intellectual. Rather, it is only per accidens, through some transformation of the body according to sensible qualities. For a heating influence cannot impress the species of heat upon the interior sense before it causes real heat which objectively moves the sense of touch.
And when it is said, according to the astronomers, that human beings’ dreams have sometimes been found conformable to the dispositions and images of the stars—for example, Pisces, Cancer, and so forth—it is said that this reasoning has either never been verified by experience, or that the correspondence is by chance, or that someone practiced in matters of this kind will, after the dream—but not before it—find some concordance in the heaven with the thing, or things, about which he dreamed.
But blessed Augustine, in his literal commentary On Genesis, says: “This indeed could have occurred through the hidden deception of malignant spirits, who have been accustomed, by the propagation of the stars, thus to delude human beings intent upon such vanities, unto their damnation and the prognostication of error.”
And it is denied that the humor which is called melancholy or choler produces in a dreaming or frenzied human being species that are hot or moist, or species of goats or serpents, or the species of anything whatsoever that differ specifically from those humors, although such things are accustomed to appear to those persons.
The reason for the denial is that a natural cause cannot per se produce the species of its real effect in the sense or intellect before it produces that effect in real existence.
But if it is asked whence phantastic apparitions of this kind are caused in dreams, it is said that they occur from the irregularity of the motion of spirits and fumes, and of the interior parts of the organs in which sensation occurs and phantasms are conserved. These phantasms are confused with one another by such motions and are monstrously conjoined. And in this manner such apparitions of dreams occur.
These things are from Albert and Henry.