the world, it follows that whatever comes into existence must have an originator. Then, if it is supposed that he argues from contingency, either from the outset or alongside the argument from things coming into existence, the knowledge that a contingent being depends upon a necessary being is self-evident and does not depend on disproving an infinite regress.

[Refuting Infinite Regress]

Moreover, there are many ways to refute an infinite regress. Several arguments may be advanced here:

The First Argument

One is that all existing things must either be necessary in existence, contingent in existence, or impossible in existence. All three alternatives are false; hence, some must be necessary and others contingent.

The third alternative is false because whatever exists cannot be impossible in existence.

The second alternative is also false, because a contingent being is one that [can] either exist or not exist, and whatever is of this kind exists only through something else. Thus, if all existing things were contingent, they would all depend upon something other than themselves. Whatever does not exist is nonexistent, and it is self-evident that the nonexistent cannot bring the existent into being.

The first alternative is also false, because we observe things coming into existence after not having existed, such as animals, plants, minerals, clouds, and rain.