Matt W. notes the perplexity over at TAR caused by the following remark of Williamson’s:
Knowledge is the norm of belief: a flat-out belief is fully justified if and only if it constitutes knowledge.
The perplexity is caused by reading his use of the language of justification in terms of that notion typically employed in the attempt to analyze knowledge. I don’t think this is what Williamson is saying, and the following passage from Knowledge and Its Limits (pp. 255-6) makes clear how to understand the remark above:
On this analogy between assertion and belief, the knowledge rule for assertion does not correspond to an identification of reasonable belief with knowledge. . . . The rule makes knowledge the condition for permissible assertion, not for reasonable assertion. One may reasonably do something impermissible because one reasonable but falsely believes it to be permissible. In particular, one may reasonabley assert p, even though one does not know p, because it is very probable on one’s evidence that one knows p. In the same circumstances, one may reasonably but impermissibly believe p without knowing p.
Given the distinction between reasonability and permissibility, I think it is clear that the ordinary notion of justification employed in the typical analysis of knowledge is what Williamson refers to as reasonability, and Williamson’s use of “fully justified” in the former quote corresponds to his language of permissibility in the latter quote.