Dist. 8, Part 2, Art. 1, Q. 3
by St. Bonaventure
Source text: Public Domain Mark 1.0. English translation/apparatus/encoding: CC BY-NC 4.0, Wroot Press.
https://bonaventure.wrootpress.com/browse/2/d/8/q/bon-sent-II-d8-p2-a1-q3
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### QUESTION III.
### *Whether the demons can delude the senses.*

In the third place it is asked whether a demon can delude the senses. And that it can, it seems.

*Foundations.* 1. Upon that [text] of Exodus 7: *The magicians did the like by enchantments and certain secret arts*, the Gloss of Rabanus [says]: «By diabolic figments they deluded the eyes of the spectators, so that things remaining in their own species seemed to be others».

2. Likewise, in the *Itinerary of Clement* Niceta said

to Peter, narrating the prestidigitations of Simon: «We have seen dogs sing and statues walk»; it is settled that this did not happen except by the power of demons. If, then, demons do these things and many like them, which can in no way come about except miraculously: therefore they delude the eyes of spectators, especially when they seem to do things which by the aid of nature [these spectators] cannot be helped to [achieve].

3. Likewise, in the *Lives of the Fathers* it is read that certain people brought a girl to a holy father, who [the girl] seemed to them to be a mare; but the holy father discerned that she was a girl: therefore if this came about by the diabolical art, [it is] manifest etc.

4. Likewise, it is more [to] deceive the intellect than the sense; but demons deceive and seduce many as to the intellect: therefore much more strongly can they seduce or delude [men] as to the sense.

**On the contrary:** 1. «The particular sense, as the Philosopher says, does not err about its proper object»; therefore it does not perceive except what is true; but a delusion of the senses cannot be without error and deception: therefore etc.

2. Likewise, when the devil makes someone see an ass, or some other animal, where it is not in truth, it is necessary that he make the likeness of that animal in the eye; but that likeness cannot be generated except from that animal, since it cannot be educed from nothing: therefore either he must bring the ass, or he never makes it be seen. But if he brings the ass, it is no illusion; if he does not bring [it], he does not alter [anything]: therefore he can never alter by deluding nor delude by altering.

3. Likewise, when he makes a man be seen as a goat, either the likeness of the man comes through up to the eye, or not. If yes: then since [the sense] judges according to the likeness received, it will judge him to be a man: therefore it will not be deceived. If [the likeness] does not come through: I ask what hinders [it]? and it seems that nothing can [hinder it]. For with the medium illuminated, it is necessary that the object be multiplied through the medium, if there be no bodily obstacle: therefore it seems that in no way can there be a delusion of sense there.

4. Likewise, when he makes seen what is not, either he does this by altering the *power*, or by altering the *eye*, or the *object*. If by altering the *object*, then it is a true miracle, not a prestidigitation. If by altering the *organ* or *power*, since these are more worthy, then it will be a greater miracle: therefore false miracles will be greater than true ones; and if this is false, the same returns [as before].

### CONCLUSION.

> A demon can delude our senses, either by showing as present what is not, or by showing otherwise than [a thing] is, or by hiding what is present.

**I respond:** For the understanding of what has been said, it is to be attended to that without doubt the demons can delude the senses, as manifold experience teaches. But to assign the *manner* is very difficult, and to this many doctors have applied themselves in divers ways.

*First opinion.* For certain men have wished to assign the manner of this delusion saying that it is above nature; and that *threefold* can this come about. For a demon can do this **by influencing from above**, **by moving phantasms from within**, **by setting forth species from without**. — *By influencing from above*, they say it can come about in this way: because a demon is by nature superior to the bodily sense; and because higher things are born to influence lower, a demon can imprint upon the sense the species which he has in himself, both interior and exterior; which species are nevertheless less spiritual in the receiver than in the giver, because «what is received in something is according to the mode of the receiver, not according to the mode of what is received». — Similarly, *by moving phantasms from within*, they say it can happen thus: as it happens in dreams, that from a motion of phantasms and a flowing down from the [interior] organ the sensitive power is excited within and a dream comes about, in which it seems to the man that he sees or hears the truth, when the phantasm of a thing comes through to the organ of sight or hearing: so also in [the case] proposed a demon can make phantasms existing in the interior organ flow down to the organs of the senses; and thus it seems to the man that he sees or perceives the thing itself; while from the phantasm of a thing the organ is formed, and the intention of the sense is turned upon it, [the sense] judges of the likeness as if it were the truth. — *But from without by setting forth species*, [a demon] can in this way play with the sense. For each thing is born to give its species to one susceptible [of it]. And if there were something which not only would receive the species but could also retain [it]; it could be carried about and offered to someone in place of truth; as the moon is shown in a well. Because, then, the nature of a mirror is not hidden from the demon — [a mirror] not only receptive of species but also retentive [of them] — by means of it [the demon] can offer to our senses, in place of truth, the species of whatever thing he wishes; and when they take it for truth, they are deluded. — This threefold mode, therefore, they say is possible to a demon; and that he uses now this, now

another, and now a third. — But each of these modes, to one inwardly considering [them], has something improbable. For it does not seem possible that a spiritual substance, which has in itself species wholly immaterial, can imprint them on the senses, since it is altogether a power incommensurable [with sense]. Nor again does it seem that a species can regress from the interior organ, since this is a retrograde order. Moreover, it is very strange if a demon finds so great a mirror, in which in its magnitude and breadth he can show a [whole] castle, as has sometimes been shown to many. It is also strange if someone sees a thing thus, [and yet] cannot see the mirror. The nature too of such a bodily thing is marvelous, [one] which can receive and retain a species, since we see that a species cannot sensibly be separated from its object.

*Opinion of the author (second conclusion).* Therefore there is another mode of speaking, which is more consonant with nature and with intelligibility: that a demon can delude the senses *either by showing as present what is not, or by showing otherwise than [a thing] is, or by hiding what is present*. The first he does *by setting forth species*, the second by *varying the sense or the object*, the third by *furnishing an impediment*.

*First mode.* The first can be understood thus. When phantasms existing within are set forth by a strong setting-forth upon the interior power itself, or [when] the interior power strongly attends to them; the likeness of a thing seems to be the truth. This is manifest by nature. For to a frenzied man, on account of the rising of fumes to the brain, from some slight external occasion it seems to him that he sees many things which are not present to him, or that he hears [them]. Similarly, through a strong turning of attention, a phantasm seems [to be] truth, as Augustine exemplifies in the book *On the Trinity*, that someone with so great a conversion was recalling the image of a certain woman, that he seemed to himself to be carnally mingled with her, even while waking.

*Application.* Through this mode a demon can either turn the attention toward an image, or by sending in certain fumes alter the animal spirit and vary the phantasms diversely and set them forth to the attention, and so make diverse things appear to a man; and in this mode he most frequently uses [his power]. And the sign of this is that he never makes a man perceive something whose image he does not have in the interior organ of the imaginative power. For he never makes those naturally blind to dream of colors, nor the deaf [to dream] of sounds, nor does he represent such things to them in waking or in sleep.

*Second mode.* The second mode we can understand thus. That a thing should appear to the sense in another mode or under a different disposition than it is naturally, can come about on account of some variation on the side of the *organ*; as when a sanguine humor or a fiery vapor descends to the eyes, it seems to the man that things which are externally [present] are red; or on account of some variation on the side of the *object*, as it sometimes happens that from the position of a candle and the disposition of straws, straws are seen to be serpents by natural operation. The like [happens] in some powers of certain mineral things.

*Application.* And because this mode is not hidden from the demons, and they are swift ministers, capable of bringing immediately those things which are necessary for these [effects]; therefore they frequently delude our senses, showing the thing otherwise than it is, by making it appear otherwise than it is. Which indeed is brought about by inducing a slight variation around the organ or the object; which variation does not change the *form*, but is rather from a certain *accidental adherence*, and is as a *passion*, not as a *passible quality*.

*Third mode.* The third mode we can understand thus. A thing which is at hand can be hidden from our sense, without any visible obstacle, in two ways: either because the *power of the sense* is impeded from coming through to the sensible; or because the *sensible species* is impeded from coming through to the sense; and in either mode the sense is impeded from perceiving what is at hand to it.

*Application.* Now each of these is sufficiently to be believed possible to the power of a demon. And therefore [the demon] is said to be able by this way to render a man invisible, which nevertheless is not *certain*; *Notandum.* if, however, it is [so], that by this way [the thing] can come about, it is not very incredible.

These [points] having been seen, the response to the question proposed is plain — that it is to be terminated in the affirmative; and the response to the objections is plain in part.

*Solution of the opposed [arguments].* 1. For to that which is objected, that the sense does not err about its proper object; it must be said that this is understood [to be true] as far as concerns its own nature, with the *middle disposition of the organ, of the medium, and of the object* preserved. *It is understood also of the particular sense per se.* But in this deception the common sense or *phantasy*, which is called *collative*, is admixed to the particular sense and judges that to be another's which is its own.

2. To that which is objected, that no thing can be seen except through its own species; it must be said that [the demon] neither newly gives nor newly brings a species; but that one which was in the phantasy he so vividly sets forth to that interior power that [the power] believes [itself] to look upon an exterior sensible thing.

3. To that which is objected, that he makes a man be seen as a goat — whether the species of the man is borne to the sight; it must be said that perhaps he hinders [the species] from coming through to the sight, or the sight [from coming through] to it, or at least hinders [it] from coming through to judgment, while in place of that [species] he sets forth the species of a goat which he has in the phantasy; and so, while [the sense] looks upon a human body, it esteems itself to see a goat.

4. To that which is asked, where he makes the alteration — whether around the organ, or the object, or the power; it must be said that he can do and does [it] around all these for the place and time, as it seems to him expedient. Nor however does it follow that it is a true miracle, because there is not there a true transmutation or induction of forms, but only a certain transitory and as it were momentary alteration, which, while it shows there to be a true transmutation around a thing, is not a *true miracle*, but a *vain and false prestidigitation*.