(CG 3/100). That the things which God does beyond the Order of Nature are?... (Book 3. God, the End of Creatures) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

THINGS that are done occasionally by divine power outside of the usual established order of events are commonly called miracles (wonders). We wonder when we see an effect and do not know the cause. And because one and the same cause is sometimes known to some and unknown to others, it happens that of the witnesses of the effect some wonder and some do not wonder: thus an astronomer does not wonder at seeing an eclipse of the sun, at which a person that is ignorant of astronomy cannot help wondering. An event is wonderful relatively to one man and not to another. The absolutely wonderful is that which has a cause absolutely hidden. This then is the meaning of the word 'miracle,' an event of itself full of wonder, not to this man or that man only. Now the cause absolutely hidden to every man is God, inasmuch as no man in this life can mentally grasp the essence of God (Chap. XLVII). Those events then are properly to be styled miracles, which happen by divine power beyond the order commonly observed in nature.

THEse miracles there are several ranks and orders. Miracles of the highest rank are those in which something is done by God that nature can never do. Miracles of the second rank are those in which God does something that nature can do, but not in that sequence and connexion. Thus it is a work of nature that an animal should live, see and walk: but that it should live after death, see after blindness, walk after lameness, these things nature is powerless to effect, but God sometimes brings them about miraculously. A miracle of the third rank is something done by God, which is usually done by the operation of nature, but is done in this case without the working of natural principles, as when one is cured by divine power of a fever, in itself naturally curable, or when it rains without any working of the elements.