ABSTRACT
The regress is a sequence of attempts at justification — none of which succeed, precisely because there is never an end to the need for such attempts. The regress is, in effect, a very long guess — infinitely long, in fact, because each proposition in turn is, in effect, a guess. The skeptic argues that no such sequence ever ends. For one belief to be justified, some further belief or experience is needed. That further belief must be justified, too. Other skeptical arguments also rely on UB. For example, according to the dreaming argument, knowing that students are in London would depend on them knowing that they are not dreaming being there. UB implies that students have never provided quite enough justification for a given belief. Always, more is needed; always, there is unfinished business.
