Formulating general principles determining when criterial warrant is difficult and is not undermined (Pollock, 1974). So one might think that warrant in general depends just on what is presupposed as true and relevant in a potentially shifting context of thought or conversation, not on general criteria. However, defenders of criteria may protest that coherence, at least, remains as a criterion applicable across contexts.
It is often felt that ‘p’ cannot be evident by satisfying criteria unless (a) criterial considerations evidently obtain, and evident either that (b) the criteria have certain correctness-masking features, e.g., leading to truth, or must that © the criteria are correct. Otherwise any conformity to pertinent standards is in a relevant sense only accidental (BonJour, 1985). Yet vicious regress or circularity looms, unless in supporting propositions are evident without criteria. At worst, as sceptics argue, nothing can be warranted: At best, a consistent role for criteria is limited. A common reply is that being criterially warranted, by definition, just requires the adequate (checkable) criterial considerations in fact obtain, i.e., in that there is no need to demand further cognitive achievements for which one or more must also be evident, e.g., actually checking that criterial considerations obtain, proving truth or likelihood of truth on the basis of these considerations, or proving warrant on their basis.
Even so, how can propositions state which putative criteria are correct, be warranted? Any proposal for criterial warrant invokes the classic sceptical change of vicious regress or circularity. Yet, again, it may arguably, as with ‘p’ above, correct criteria must in fact be satisfied, but this fact itself need not be already confronting ‘us’ as warranted. So, one might argue there is no debilitating regress or circle of warrant, even when, as may happen with some criterion, its correctness is warranted ultimately only because it itself is satisfied (van Cleve, 1979). Independent, ultimately non-criterial, evidence is not needed. Nonetheless, suppose we argue that our criteria are correct, because, e.g., they led to truth, are confirmed by thought experiments, or are clearly and distinctly conceived as correct, etc. however, we develop our arguments, they would not persuade those who, doubting the criteria we conform to, doubt our premises or their relevancy, dismissing our failures as merely conversational and irrelevant to our warrant, moreover, may strike sceptics and non-skeptics alike as question-begging or as arbitrarily altering what warrant requires. For the charge of ungrounded dogmatism it is inappropriate, more than the consistency of criterial warrant, including warrant about warrant, may be required, no matter what putative criteria we conform to.
It is nevertheless, a problem of the criterion that lay upon the difficulty of how both to formulate the criteria, and to determine the extent, of knowledge and justified belief. The problem arises from the seeming justification of which is proven plausible of the following two propositions:
(1) I can identify instances (and thus determiners the
extent) of justified belief only if I already know the criteria
of it.
(2) I can know the criteria of justified belief only if I can
already identify the instances of it.
If both (1) and (2) were true, I would be caught in a circle: I could know neither the criteria nor the extent of justified belief. In order to show that both can be known after all, a way out of the circle must be found. The nature of this task is best illustrated by considering the four positions that may be taken concerning the truth-values of (1) and (2):
(a) Scepticism as to the possibility of constructing a
theory of justification:
Both (1) and (2) are true, consequently, I can know neither the criteria nor the extent of justified belief. This kind of scepticism is restricted in its scope to epistemic propositions. While it allows for the possibility of justified beliefs, it denies that we can know which beliefs are justified and which are not (b) is true but (1) is false: I can identify instances of justification without applying a criterion.
(1) is true but (2) is false? I can identify the criteria of justified belief without prior knowledge of its instances.
(d) Both (1) and (2) are false: I can know the extent of