60. The second objection is from the sufficiency of nature to explain everything we observe.
A. What is able to be completed by fewer principles is not done by many.
B. Supposing God does not exist, natural things can be reduced to natural principles, and intentional things are reduced to principles that are human or voluntary.
C. Thus it is not necessary to suppose that God exists.
61. His response to the second objection appeals primarily to the fifth way: the determinacy of natural ends depends on the direction of something supernatural, i.e. God.
62. However, the second half of his reply is in a way a summary of all five ways put together: all things mobile and defectible must be reduced to some immobile and necessary first principle.
Outline of Article
—There is evil in the world.
—Nature is adequate to explain natural things.
—I am that am.
—All motion must be reduced to some immobile first principle.
—In any chain of efficient causes, the efficacy of the intermediate depends on the efficacy of the first.
—If there were nothing utterly permanent, nothing would exist; but if there is one necessary, there must be a first necessary.
—The degrees of being and perfection must be traced to a first principle which is supremely perfect and subsistent being.
—The directedness of natural things is explicable only on account of a designer who gives direction to all natures.
—Creatures are distinct from God. God wills the good, but allows evil.
—Answered in Corpus