ABSTRACT
Throughout the Aristotelian tradition in antiquity and the middle ages, infinite regress has been the hallmark of impossibility, providing a prime instrument of philosophical refutation. However, where Aristotle flatly rejected actual infinities, the medievals were more cautious. God, after all, is in various aspects infinite: his knowledge, goodness, etc. knows no bounds. But the rejection of the idea that infinite processes—be they progressive or regressive—could yield a meaningful product continued to form a key doctrine of medieval Aristotelianism. 1
