In the Metaphysical Disputations (disp. 20), Suarez presents his argument for the existence of God, based on the principle that everything made is made by something other than itself. In the process of elaborating this argument, he argues that it is impossible for there to be either a circular regress or an infinite regress of makers. This, in very rough paraphrase, is his argument against circular regress:
The existence of A is implied in the claim that A makes B, for any A and B; if B in turn makes A, then A's existence must be supposed already as a precondition for B's making A. But to be made is to be made to exist; so we have the absurdity that A both exists and does not exist. Therefore it is impossible to have a circular regress of makers.
His argument, again in rough paraphrase, against infinite regress:
Everything that is made is made by another. This is obviously true because it is obviously true that everything that is dependent depends on something other than hitself. If the whole collection of dependent things and things on which they depend were dependent it would depend on something other than itself. It is impossible, however, that the whole collection be dependent in its being and in its operation on some other thing: if it were, it would not be the whole collection.
Now, if every being distributively were dependent and made, the whole would be so, not by a single dependence or but by a collection of them; this is precisely the way in which a whole like this is dependent. But the whole collection of dependent things and things on which they depend cannot be dependent, as noted above. Therefore there must be something indepedent which terminates the chain of dependence. Thus, no infinite regress is possible.
These are interesting kinds of argument. The one against circular regress is exactly right; circular regress is not possible with makers and made things. I'm not so sure about the argument against infinite regress. It's plausible, and I follow it completely up through the claim that the whole chain of dependent things & things on which they depend cannot be dependent, on pain of contradiction. I'm not so clear on how Suarez pulls a contradiction out of his further considerations on distributive dependence; and to rule out infinite regress one needs to show that it leads (in the given circumstances) to a contradiction. I'll have to reflect a bit more on Suarez's argument here. You can expect another post on it at some future (perhaps distant future) date.