would not be unless the power of the soul could
change corporeal matter. Therefore man can change corporeal matter by
the power of his soul.

Obj. 3: Further, the human body is nobler than other inferior bodies.
But by the apprehension of the human soul the human body is changed
to heat and cold, as appears when a man is angry or afraid: indeed
this change sometimes goes so far as to bring on sickness and death.
Much more, then, can the human soul by its power change corporeal
matter.

_On the contrary,_ Augustine says (De Trin. iii, 8): "Corporeal
matter obeys God alone at will."

_I answer that,_ As stated above (Q. 110, A. 2), corporeal matter is
not changed to (the reception of) a form save either by some agent
composed of matter and form, or by God Himself, in whom both matter
and form pre-exist virtually, as in the primordial cause of both.
Wherefore of the angels also we have stated (Q. 110, A. 2) that they
cannot change corporeal matter by their natural power, except by
employing corporeal agents for the production of certain effects.
Much less therefore can the soul, by its natural power, change
corporeal matter, except by means of bodies.

Reply Obj. 1: The saints are said to work miracles by the power of
grace, not of nature. This is clear from what Gregory says in the
same place: "Those who are sons of God, in power, as John says--what
wonder is there that they should work miracles by that power?"

Reply Obj. 2: Avicenna assigns the cause of bewitchment to the fact
that corporeal matter has a natural tendency to obey spiritual
substance rather than natural contrary agents. Therefore when the
soul is of strong imagination, it can change corporeal matter. This
he says is the cause of the "evil eye."

But it has been shown above (Q. 110, A. 2) that corporeal matter
does not obey spiritual substances at will, but the Creator alone.
Therefore it is better to say, that by a strong imagination the
(corporeal) spirits of the body united to that soul are changed,
which change in the spirits takes place especially in the eyes, to
which the more subtle spirits can reach. And the eyes infect the air
which is in contact with them to a certain distance: in the same way
as a new and clear mirror contracts a tarnish from the look of a
"menstruata," as Aristotle says (De Somn. et Vigil.; [*De Insomniis
ii]).

Hence then when a soul is vehemently moved to wickedness, as occurs
mostly in little old women, according