Objection 1. It would seem possible that something may occur outside the order of the Divine government. For Boethius says (De Consol. iii) that "God disposes all for good." Therefore, if nothing happens outside the order of the Divine government, it would follow that no evil exists.
Objection 2. Further, nothing that is in accordance with the pre-ordination of a ruler occurs by chance. Therefore, if nothing occurs outside the order of the Divine government, it follows that there is nothing fortuitous and casual.
Objection 3. Further, the order of Divine Providence is certain and unchangeable; because it is in accordance with the eternal design. Therefore, if nothing happens outside the order of the Divine government, it follows that all things happen by necessity, and nothing is contingent; which is false. Therefore it is possible for something to occur outside the order of the Divine government.
On the contrary, It is written (Esther 13:9): "O Lord, Lord, almighty King, all things are in Thy power, and there is none that can resist Thy will."
I answer that, It is possible for an effect to result outside the order of some particular cause; but not outside the order of the universal cause. The reason of this is that no effect results outside the order of a particular cause, except through some other impeding cause; which other cause must itself be reduced to the first universal cause; as indigestion may occur outside the order of the nutritive power by some such impediment as the coarseness of the food, which again is to be ascribed to some other cause, and so on till we come to the first universal cause. Therefore as God is the first universal cause, not of one genus only, but of all being in general, it is impossible for anything to occur outside the order of the Divine government; but from the very fact that from one point of view something seems to evade the order of Divine providence considered in regard to one particular cause, it must necessarily come back to that order as regards some other cause.
Reply to Objection 1. There is nothing wholly evil in the world, for evil is ever founded on good, as shown above (Question 48, Article 3). Therefore something is said to be evil through its escaping from the order of some particular good. If it wholly escaped from the order of the Divine government, it would wholly cease to exist.
Reply to Objection 2. Things are said to be fortuitous as regards some particular cause from the order of which they escape. But as to the order of Divine providence, "nothing in the world happens by chance," as Augustine declares (QQ. 83, qu. 24).
Reply to Objection 3. Certain effects are said to be contingent as compared to their proximate causes, which may fail in their effects; and not as though anything could happen entirely outside the order of Divine government. The very fact that something occurs outside the order of some proximate cause, is owing to some other cause, itself subject to the Divine government.
Source: Summa Theologica (New Advent)