111 THE ACTION OF THE ANGELS ON MAN
We now consider the action of the angels on man, and inquire: (1) How far they can
change them by their own natural power; (2) How they are sent by God to the ministry of
men; (3) How they guard and protect men.
Under the first head there are four points of inquiry:
(1) Whether an angel can enlighten the human intellect?
(2) Whether he can change man's will?
(3) Whether he can change man's imagination?
(4) Whether he can change man's senses?

111 ARTICLE 1
Whether an angel can enlighten man?
Objection 1
It would seem that an angel cannot enlighten man. For man is enlightened by faith;
hence Dionysius (Eccl. Hier. iii) attributes enlightenment to baptism, as "the
sacrament of faith." But faith is immediately from God, according to Eph. 2:8:
"By grace you are saved through faith, and that not of yourselves, for it is the gift
of God." Therefore man is not enlightened by an angel; but immediately by God.
Objection 2
Further, on the words, "God hath manifested it to them" (Rm. 1:19), the gloss
observes that "not only natural reason availed for the manifestation of Divine truths
to men, but God also revealed them by His work," that is, by His creature. But both
are immediately from God---that is, natural reason and the creature. Therefore God
enlightens man immediately.
Objection 3
Further, whoever is enlightened is conscious of being enlightened. But man is not
conscious of being enlightened by angels. Therefore he is not enlightened by them.
On the contrary
On the contrary, Dionysius says (Coel. Hier. iv) that the revelation of Divine things
reaches men through the ministry of the angels. But such revelation is an enlightenment as
we have stated (Q106, ARTICLE 1; Q107, ARTICLE 2). Therefore men are enlightened by the
angels.
Body
I answer that, Since the order of Divine Providence disposes that lower things be
subject to the actions of higher, as explained above (Q109, ARTICLE 2); as the inferior
angels are enlightened by the superior, so men, who are inferior to the angels, are
enlightened by them.
The modes of each of these kinds of enlightenment are in one way alike and in another
way unlike. For, as was shown above (Q106, ARTICLE 1), the enlightenment which consists in
making known Divine truth has two functions; namely, according as the inferior intellect
is strengthened by the action of the superior intellect, and according as the intelligible
species which are in the superior intellect are proposed to the inferior so as to be
grasped thereby. This takes place in the angels when the superior angel divides his
universal concept of the truth according to the capacity of the inferior angel, as
explained above (Q106, ARTICLE 1).
The human intellect, however, cannot grasp the universal truth itself unveiled; because
its nature requires it to understand by turning to the phantasms, as above explained (Q84,
ARTICLE 7). So the angels propose the intelligible truth to men under the similitudes of
sensible things, according to what Dionysius says (Coel. Hier. i), that, "It is
impossible for the divine ray to shine on us, otherwise than shrouded by the variety of
the sacred veils." On the other hand, the human intellect as the inferior, is
strengthened by the action of the angelic intellect. And in these two ways man is
enlightened by an angel.
Reply to objection 1
Two dispositions concur in the virtue of faith; first, the habit of the intellect
whereby it is disposed to obey the will tending to Divine truth. For the intellect assents
to the truth of faith, not as convinced by the reason, but as commanded by the will; hence
Augustine says, "No one believes except willingly." In this respect faith comes
from God alone. Secondly, faith requires that what is to be believed be proposed to the
believer; which is accomplished by man, according to Rm. 10:17, "Faith cometh by
hearing"; principally, however, by the angels, by whom Divine things are revealed to
men. Hence the angels have some part in the enlightenment of faith. Moreover, men are
enlightened by the angels not only concerning what is to be believed; but also as regards
what is to be done.
Reply to objection 2
Natural reason, which is immediately from God, can be strengthened by an angel, as we
have said above. Again, the more the human intellect is strengthened, so much higher an
intelligible truth can be elicited from the species derived from creatures. Thus man is
assisted by an angel so that he may obtain from creatures a more perfect knowledge of God.
Reply to objection 3
Intellectual operation and enlightenment can be understood in two ways. First, on the
part of the object understood; thus whoever understands or is enlightened, knows that he
understands or is enlightened, because he knows that the object is made known to him.
Secondly, on the part of the principle; and thus it does not follow that whoever
understands a truth, knows what the intellect is, which is the principle of the
intellectual operation. In like manner not everyone who is enlightened by an angel, knows
that he is enlightened by him.

111 ARTICLE 2
Whether the angels can change the will of man?
Objection 1
It would seem that the angels can change the will of man. For, upon the text, "Who
maketh His angels spirits and His ministers a flame of fire" (Heb. 1:7), the gloss
notes that "they are fire, as being spiritually fervent, and as burning away our
vices." This could not be, however, unless they changed the will. Therefore the
angels can change the will.
Objection 2
Further, Bede says (Super Matth. xv, 11), that, "the devil does not send wicked
thoughts, but kindles them." Damascene, however, says that he also sends them; for he
remarks that "every malicious act and unclean passion is contrived by the demons and
put into men" (De Fide Orth. ii, 4); in like manner also the good angels introduce
and kindle good thoughts. But this could only be if they changed the will. Therefore the
will is changed by them.
Objection 3
Further, the angel, as above explained, enlightens the human intellect by means of the
phantasms. But as the imagination which serves the intellect can be changed by an angel,
so can the sensitive appetite which serves the will, because it also is a faculty using a
corporeal organ. Therefore as the angel enlightens the mind, so can he change the will.
On the contrary
On the contrary, To change the will belongs to God alone, according to
Prov. 21:1:
"The heart of the king is in the hand of the Lord, whithersoever He will He shall
turn it."
Body
I answer that, The will can be changed in two ways. First, from within; in which way,
since the movement of the will is nothing but the inclination of the will to the thing
willed, God alone can thus change the will, because He gives the power of such an
inclination to the intellectual nature. For as the natural inclination is from God alone
Who gives the nature, so the inclination of the will is from God alone, Who causes the
will.
Secondly, the will is moved from without. As regards an angel, this can be only in one
way---by the good apprehended by the intellect. Hence in as far as anyone may be the cause
why anything be apprehended as an appetible good, so far does he move the will. In this
way also God alone can move the will efficaciously; but an angel and man move the will by
way of persuasion, as above explained (Q106, ARTICLE 2).
In addition to this mode the human will can be moved from without in another way;
namely, by the passion residing in the sensitive appetite: thus by concupiscence or anger
the will is inclined to will something. In this manner the angels, as being able to rouse
these passions, can move the will, not however by necessity, for the will ever remains
free to consent to, or to resist, the passion.
Reply to objection 1
Those who act as God's ministers, either men or angels, are said to burn away vices,
and to incite to virtue by way of persuasion.
Reply to objection 2
The demon cannot put thoughts in our minds by causing them from within, since the act
of the cogitative faculty is subject to the will; nevertheless the devil is called the
kindler of thoughts, inasmuch as he incites to thought, by the desire of the things
thought of, by way of persuasion, or by rousing the passions. Damascene calls this
kindling "a putting in" because such a work is accomplished within. But good
thoughts are attributed to a higher principle, namely, God, though they may be procured by
the ministry of the angels.
Reply to objection 3
The human intellect in its present state can understand only by turning to the
phantasms; but the human will can will something following the judgment of reason rather
than the passion of the sensitive appetite. Hence the comparison does not hold.

111 ARTICLE 3
Whether an angel can change man's imagination?
Objection 1
It would seem that an angel cannot change man's imagination. For the
phantasy, as is
said De Anima iii, is "a motion caused by the sense in act." But if this motion
were caused by an angel, it would not be caused by the sense in act. Therefore it is
contrary to the nature of the phantasy, which is the act of the imaginative faculty, to be
changed by an angel.
Objection 2
Further, since the forms in the imagination are spiritual, they are nobler than the
forms existing in sensible matter. But an angel cannot impress forms upon sensible matter
(Q110, ARTICLE 2). Therefore he cannot impress forms on the imagination, and so he cannot
change it.
Objection 3
Further, Augustine says (Gen. ad lit. xii, 12): "One spirit by intermingling with
another can communicate his knowledge to the other spirit by these images, so that the
latter either understands it himself, or accepts it as understood by the other." But
it does not seem that an angel can be mingled with the human imagination, nor that the
imagination can receive the knowledge of an angel. Therefore it seems that an angel cannot
change the imagination.
Objection 4
Further, in the imaginative vision man cleaves to the similitudes of the things as to
the things themselves. But in this there is deception. So as a good angel cannot be the
cause of deception, it seems that he cannot cause the imaginative vision, by changing the
imagination.
On the contrary
On the contrary, Those things which are seen in dreams are seen by imaginative vision.
But the angels reveal things in dreams, as appears from Mt. 1:20;2:13,19 in regard to the
angel who appeared to Joseph in dreams. Therefore an angel can move the imagination.
Body
I answer that, Both a good and a bad angel by their own natural power can move the
human imagination. This may be explained as follows. For it was said above (Q110, ARTICLE
3), that corporeal nature obeys the angel as regards local movement, so that whatever can
be caused by the local movement of bodies is subject to the natural power of the angels.
Now it is manifest that imaginative apparitions are sometimes caused in us by the local
movement of animal spirits and humors. Hence Aristotle says (De Somn. et Vigil.) *De
Insomniis iii., when assigning the cause of visions in dreams, that "when an animal
sleeps, the blood descends in abundance to the sensitive principle, and movements descend
with it," that is, the impressions left from the movements are preserved in the
animal spirits, "and move the sensitive principle"; so that a certain appearance
ensues, as if the sensitive principle were being then changed by the external objects
themselves. Indeed, the commotion of the spirits and humors may be so great that such
appearances may even occur to those who are awake, as is seen in mad people, and the like.
So, as this happens by a natural disturbance of the humors, and sometimes also by the will
of man who voluntarily imagines what he previously experienced, so also the same may be
done by the power of a good or a bad angel, sometimes with alienation from the bodily
senses, sometimes without such alienation.
Reply to objection 1
The first principle of the imagination is from the sense in act. For we cannot imagine
what we have never perceived by the senses, either wholly or partly; as a man born blind
cannot imagine color. Sometimes, however, the imagination is informed in such a way that
the act of the imaginative movement arises from the impressions preserved within.
Reply to objection 2
An angel changes the imagination, not indeed by the impression of an imaginative form
in no way previously received from the senses (for he cannot make a man born blind imagine
color), but by local movement of the spirits and humors, as above explained.
Reply to objection 3
The commingling of the angelic spirit with the human imagination is not a mingling of
essences, but by reason of an effect which he produces in the imagination in the way above
stated; so that he shows man what he the angel knows, but not in the way he knows.
Reply to objection 4
An angel causing an imaginative vision, sometimes enlightens the intellect at the same
time, so that it knows what these images signify; and then there is not deception. But
sometimes by the angelic operation the similitudes of things only appear in the
imagination; but neither then is deception caused by the angel, but by the defect in the
intellect to whom such things appear. Thus neither was Christ a cause of deception when He
spoke many things to the people in parables, which He did not explain to them.

111 ARTICLE 4
Whether an angel can change the human senses?
Objection 1
It seems that an angel cannot change the human senses. For the sensitive operation is a
vital operation. But such an operation does not come from an extrinsic principle.
Therefore the sensitive operation cannot be caused by an angel.
Objection 2
Further, the sensitive operation is nobler than the nutritive. But the angel cannot
change the nutritive power, nor other natural forms. Therefore neither can he change the
sensitive power.
Objection 3
Further, the senses are naturally moved by the sensible objects. But an angel cannot
change the order of nature (Q110, ARTICLE 4). Therefore an angel cannot change the senses;
but these are changed always by the sensible object.
On the contrary
On the contrary, The angels who overturned Sodom, "struck the people of Sodom with
blindness or {aorasia}, so that they could not find the door" (Gn. 19:11). *It is
worth noting that these are the only two passages in the Greek version where the word
{aorasia} appears. It expresses, in fact, the effect produced on the people of
Sodom---namely, dazzling (French version, "eblouissement"), which the Latin
"caecitas" (blindness) does not necessarily imply. The same is recorded of the
Syrians whom Eliseus led into Samaria (4 Kgs. 6:18).
Body
I answer that, The senses may be changed in a twofold manner; from without, as when
affected by the sensible object: and from within, for we see that the senses are changed
when the spirits and humors are disturbed; as for example, a sick man's tongue, charged
with choleric humor, tastes everything as bitter, and the like with the other senses. Now
an angel, by his natural power, can work a change in the senses both ways. For an angel
can offer the senses a sensible object from without, formed by nature or by the angel
himself, as when he assumes a body, as we have said above (Q51, ARTICLE 2). Likewise he
can move the spirits and humors from within, as above remarked, whereby the senses are
changed in various ways.
Reply to objection 1
The principle of the sensitive operation cannot be without the interior principle which
is the sensitive power; but this interior principle can be moved in many ways by the
exterior principle, as above explained.
Reply to objection 2
By the interior movement of the spirits and humors an angel can do something towards
changing the act of the nutritive power, and also of the appetitive and sensitive power,
and of any other power using a corporeal organ.
Reply to objection 3
An angel can do nothing outside the entire order of creatures; but he can outside some
particular order of nature, since he is not subject to that order; thus in some special
way an angel can work a change in the senses outside the common mode of nature.