Always seek for the genuine article.
1 It was Avicenna’s position that matter is much more obedient to separate substances, in the production of a certain effect, than it is to the contrary agencies within matter. Consequently, he claimed that, when there is an act of apprehension in the aforesaid substances, there results at times an effect in these things here below—for instance, rain, or the healing of a sick person—without the mediation of a corporeal agent.
2 He took an indication of this from our soul. For, when it is possessed of a strong imagination, its body may be changed by an act of cognition alone. For example, when a man is walking over a beam placed at some height, he falls quite easily because, through fear, he imagines his fall. But he would not fall if the beam were placed on the earth, where there would be no possibility of fearing a fall.
It is also obvious that, simply as a result of the cognitive act of the soul, the body becomes hot, as happens in those who are prone to concupiscence, or anger; or it may also grow cold, as happens in those subject to fear. Sometimes, too, it is moved by a strong cognitive act toward some illness, such as fever, or even leprosy.
And on this basis, he says that, if the soul be pure, not subject to bodily passions, and strong in its cognitive functioning, then not only its own body, but even external bodies, obey its act of apprehension. So much so, that on the occurrence of its act of apprehension a sick person may be cured, or some similar result may occur.
And he claims that this is the explanation of the casting of a spell by fascination; namely, that the soul of a person strongly moved by malevolence has the power to inflict an injury on someone, particularly a child, who is quite susceptible to impressions, because of the tender condition of his body. Consequently, Avicenna favored the notion that it is much more likely that the cognitive functions of separate substances, which he regarded as the souls or movers of the spheres, result in certain effects in lower bodies, without the action of any corporeal agent.
Notes The placebo effect is real.
3 Now, this theory is in agreement with his other views. For he asserts that all substantial forms flow down to these lower bodies from separate substances, and that corporeal agents are merely to prepare matter to receive the impression of a separate agent. Of course, this is not true, according to the teaching of Aristotle, who proves, in the Metaphysics [VI, 8], that the forms which are in matter do not come from separate forms, but from forms which are in matter; in this way, in fact, the likeness between the maker and the thing made is discovered.
4 Moreover, the example that he takes from the influence of the soul on the body does not help his contention much. For no change in the body results from an act of apprehension unless there be attached to the apprehension some sort of emotion, such as joy or fear, or lust, or some other passion. Now, passions of this kind occur along with a definite motion of the heart, from which there results later a change of the whole body, either in the way of local motion or of alteration. Consequently, it still remains true that the act of apprehension in a spiritual substance does not alter the body except through the mediation of local motion.
5 Again, what he suggests in regard to fascination does not happen as a result of the apprehension of one person immediately changing the body of another, but because, by means of the motion of the heart, it causes a change in the body that is united with the soul; and its change reaches the eye, from which it is possible to affect something external, particularly if it is easily changed. Thus, for instance, the eye of a menstruating woman may affect a mirror.
Notes Yes it may.
6 So, with the exception of the use of the local motion of some body, a created spiritual substance cannot by its, own power produce any form in bodily matter, in the sense that matter would be directly subject to it in order to become actual in terms of a form. Of course, there is this capacity within the power of a spiritual substance: a body is obedient to it in regard to local motion. But, to move any body locally, it makes use of any naturally active power in order to produce its effects, just as the art of metal working makes use of fire in order to soften the metal. Now, this is not miraculous, properly speaking. So, the conclusion stands, that created spiritual substances do not work miracles by their own power.
7 Now, I say by their own power, since nothing prevents these substances from working miracles provided they act through divine power. This may be seen from the fact that one order of angels is specially assigned, as Gregory says, to the working of miracles. He even says that some of the saints “work miracles by their power,” and not merely through intercession.
8 However, we should bear in mind the fact that, when either angels or demons make use of natural things in order to produce definite effects, they use them as instruments, just as a physician uses certain herbs as instruments of healing. Now, there proceeds from an instrument not merely an effect corresponding to the power of the instrument, but also an effect beyond its power, in so far as it acts through the power of the principal agent. For instance, a saw or an axe could not make a bed unless they worked as things moved by the art adapted to such a product. Nor could natural heat generate flesh without the power of the vegetative soul which uses it as a sort of instrument. So, it is appropriate that certain higher effects result from these natural things, due to the fact that spiritual substances use them as instruments.
Notes From this comes the idea that a miracle is a direct expression of God’s will.
9 So, then, although such effects cannot be called miracles without qualification, since they do result from natural causes, they remain wonderful to us, in two senses. In one way, this is because such causes are applied by spiritual substances to the production of their effects, in a fashion that is strange to us. As a consequence, the works of clever artisans appear wondrous because it is not evident to other people how they are produced. In a second way, this is due to the fact that natural causes which are applied to the production of certain effects receive a particular power as a result of their being instruments of spiritual substances. This latter way comes rather close to the notion of a miracle.