Divine Providence does not Exclude Contingency from Things

Chapter 72: Divine Providence does not exclude Contingency from Things  

1. Just as divine providence does not wholly exclude evil from things, so also it does not exclude contingency, [See Aristotle, Physics, VIII, 5] or impose necessity on things.

2. It has already been shown that the operation of providence, whereby God works in things, does not exclude secondary causes, but, rather, is fulfilled by them, in so far as they act by God's power. Now, certain effects are called necessary or contingent in regard to proximate causes, but not in regard to remote causes. Indeed, the fact that a plant bears fruit is a fact contingent on a proximate cause, which is the germinative power which can be impeded and can fail, even though the remote cause, the sun, be a cause acting from necessity. So, since there are many things among proximate causes that may be defective, not all effects subject to providence will be necessary, but a good many are contingent.

3. Again, it pertains to divine providence that the grades of being which are possible be fulfilled, as is evident from what was said above. But being is divided into the contingent and the necessary, and this is an essential division of being. So, if divine providence excluded all contingency, not all grades of beings would be preserved. 

4. Besides, the nearer certain things are to God, the more they participate in His likeness; and the farther they are away, the more defective are they in regard to His likeness. Now, those that are nearest to God are quite immobile; namely, the separate substances which most closely approach the likeness of God, "Who is completely immutable. But the ones which are next to these, and which are moved immediately by those which always exist in the same way, retain a certain type of immobility by the fact that they are always moved in the same way, which is true of the celestial bodies. It follows, then, that those things which come after them and are moved by them are far distant from the immutability of God, so that they are not always moved in the same way. And beauty is evident in this order. Now, every necessary thing, as such, always exists in the same way. It would be incompatible, then, with divine providence, to which the establishment and preservation of order in things belongs, if all things came about as a result of necessity.  

5. Furthermore, that which is necessary is always. Now, no corruptible thing always exists. So, if divine providence required this, that all things be necessary, it would follow that nothing corruptible exists among things, and, consequently, nothing generable. Thus, the whole area of generable and corruptible things would be removed from reality. This detracts from the perfection of the universe. 

6. Moreover, in every motion there is some generation and corruption, for, in a thing that is moved, something begins and something ceases to be. So, if all generation and corruption were removed as a result of taking away the contingency of things, as we showed, the consequence would be that even motion would be taken away from things, and so would all movable things. 

7. Besides, the weakening of the power of any substance, and the hindering of it by a contrary agent, are due to some change in it. So, if divine providence does not prevent motion from going on in things, neither will the weakening of  their power be prevented, nor the blocking of their power by the resistance of another thing. Now, the result of the weakness in power, and the impeding of it, is that a thing in nature does not always work uniformly, but sometimes fails in regard to what is appropriate for it naturally; and  so, natural effects do not occur by necessity. Therefore, it is not the function of divine providence to impose necessity on things ruled by it. 
8. Furthermore, among things that are properly regulated by providence there should be none incapable of fulfillment. So, if it be manifest that some causes are contingent, because they can be prevented from producing their effects, it would evidently be against the character of providence for all things to happen out of necessity. Therefore, divine providence does not impose necessity on things by entirely excluding contingency from things.