This is clarified as follows:

If someone says, “Anything described as newly occurring and temporally originated is either possible in beginningless eternity or not,” then, if it is possible, the claim that it is impossible in beginningless eternity is invalid. If it was impossible and then became possible, this would entail its changing from being possible to being impossible without anything newly occurring at all.

If the occurrence of temporally originated events without a cause is impossible because it entails giving preference to one of the two alternatives of a possible thing without a determining factor, then the renewal or origination of possibility and admissibility without a newly occurring cause is all the more impossible, if the reality judged admissible or impossible remains the very same in relation to whatever is posited at each and every time. If that reality bears the same relation to every posited time as it does to any other, it cannot be admissible exclusively at one time rather than another. If such exclusivity is impossible without a specifying factor, and there is no specifying factor, it follows that there are two alternatives: either it is impossible at all times—but this is refuted by sense perception and consensus—or it is possible and admissible at all times. The latter must therefore hold, which is what was to be proved.

On this supposition, the counterargument they presented can be formulated in terms that are not open to the objection mentioned, as follows: “If it is said that motion has always been possible