Can an infinite regress justify everything?

It has been argued that an infinite regress of entailments cannot justify a proposition, q. For if it could, then it can be shown that any proposition can be justified in that manner, including ¬q. This chapter shows that this reductio ad absurdum weakens in the face of a so-called probabilistic regress, in which justification is only probabilistic. The reason is that, whereas a regress of entailments offers no entry point for the world, in the probabilistic regress the empirical thrust is carried by an infinite number of conditional probabilities. This chapter explains to what extent these conditional probabilities differ from the basic beliefs that lie at the heart of epistemic foundationalism.