I answer that, Certain ancient philosophers denied the government of the world, saying that all things happened by chance. But such an opinion can be refuted as impossible in two ways. First, by observation of things themselves: for we observe that in nature things happen always or nearly always for the best; which would not be the case unless some sort of providence directed nature towards good as an end; which is to govern. Wherefore the unfailing order we observe in things is a sign of their being governed; for instance, if we enter a well-ordered house we gather therefrom the intention of him that put it in order, as Tullius says (De Nat. Deorum ii), quoting Aristotle [*Cleanthes]. Secondly, this is clear from a consideration of Divine goodness, which, as we have said above (Q. 44, A. 4; Q. 65, A. 2), was the cause of the production of things in existence. For as "it belongs to the best to produce the best," it is not fitting that the supreme goodness of God should produce things without giving them their perfection. Now a thing's ultimate perfection consists in the attainment of its end. Therefore it belongs to the Divine goodness, as it brought things into existence, so to lead them to their end: and this is to govern.
Reply Obj. 1: A thing moves or operates for an end in two ways. First, in moving itself to the end, as man and other rational creatures; and such things have knowledge of their end, and of the means to the end. Secondly, a thing is said to move or operate for an end, as though moved or directed by another thereto, as an arrow directed to the target by the archer, who knows the end unknown to the arrow. Wherefore, as the movement of the arrow towards a definite end shows clearly that it is directed by someone with knowledge, so the unvarying course of natural things which are without knowledge, shows clearly that the world is governed by some reason.
Reply Obj. 2: In all created things there is a stable element, at least primary matter; and something belonging to movement, if under movement we include operation. And things need governing as to both: because even that which is stable, since it is created from nothing, would return to nothingness were it not sustained by a governing hand, as will be explained later (Q. 104, A. 1).
Reply Obj. 3: The natural necessity inherent in those beings which are determined to a particular thing, is a kind of impression from God, directing them to their end; as the necessity whereby an arrow is moved so as to fly towards a certain point is an impression from the archer, and not from the arrow. But there is a difference, inasmuch as that which creatures receive from God is their nature, while that which natural things receive from man in addition to their nature is somewhat violent. Wherefore, as the violent necessity in the movement of the arrow shows the action of the archer, so the natural necessity of things shows the government of Divine Providence. _______________________
SECOND ARTICLE [I, Q. 103, Art. 2]
Whether the End of the Government of the World Is Something Outside the World?
Objection 1: It would seem that the end of the government of the world is not something existing outside the world. For the end of the government of a thing is that whereto the thing governed is brought. But that whereto a thing is brought is some good in the thing itself; thus a sick man is brought back to health, which is something good in him. Therefore the end of government of things is some good not outside, but within the things themselves.
Obj. 2: Further, the Philosopher says (Ethic. i, 1): "Some ends are an operation; some are a work"—i.e. produced by an operation. But nothing can be produced by the whole universe outside itself; and operation exists in the agent. Therefore nothing extrinsic can be the end of the government of things.
Obj. 3: Further, the good of the multitude seems to consist in order, and peace which is the "tranquillity of order," as Augustine says (De Civ. Dei xix, 13). But the world is composed of a multitude of things. Therefore the end of the government of the world is the peaceful order in things themselves. Therefore the end of the government of the world is not an extrinsic good.
On the contrary, It is written (Prov. 16:4): "The Lord hath made all things for Himself." But God is outside the entire order of the universe. Therefore the end of all things is something extrinsic to them.