eternal universe

philosophically that is the idea that a single contingent is caused by an infinite sequence of contingents ; each member in the chain being the effect of the previous one, ad infinitum.
however, if an amount decreases, then the amount before decreasing is necessarily more than the amount after the decreasing.
the above, of an eternal regress, cannot be the case, if the amount is infinitely long; an infinity cannot be greater than or less than another infinity.
so if an actualised amount accepts decreases, then this amount cannot be infinite.
the set of all contingents is comprised on contingents, and each contingent accepts non-existence. thus, any of those contingents accepts cessation (by virtue of what it is, since a contingent is an existent that accepts non-existence by definition.)
thus it is possible for the set of all contingents to become smaller than what it is (i.e. decreasing)
therefore, the set of all contingents cannot be infinite; the set of all contingents is comprised of a finite number of contingents.

to demonstrate the absurdity if this idea were true, it would be as though the number of orbits completed by each celestial body were not finite-- then the number of orbits completed would have been either a) even, b) odd, c) neither even nor odd, or d) both even and odd. each is impossible, so the completion of an infinite number of orbits is impossible