(CG 3/15). That there is not any Sovereign Evil, acting as the Principle o... (Book 3. God, the End of Creatures) (Summa Contra Gentiles) (Aquinas, Thomas, St.)

That to which a thing tends when in absence from it, and in which it rests when in possession of it, is the scope and aim and end in view. But everything, so long as it lacks the perfection proper to it, moves towards gaining that perfection, so far as it depends upon itself so to do; and when it has gained that perfection, therein it rests. The end then of everything is its perfection. But the perfection of everything is its own good. Everything therefore is ordained to good as to its end.

4. Things that are aware of an end and things that are unaware of an end are alike ordained to an end, with this difference, that things that are aware of an end tend to an end of themselves, while things that are unaware of an end tend to an end under the direction of another, as appears in the case of archer and arrow. But things that are aware of an end are always ordained to good for their end: for the will, which is the appetite of a fore-known end, never tends to anything except under the aspect of good, which is its object. Therefore things also which are unaware of an end are ordained to good for their end, and so good is the end of all things.