Taken from Fantl/McGrath, of course: KL-justification is knowledge-level justification. Background: in Chapter 6, they use a claim about KL-justification to argue for the importance of knowledge.
The claim depends on an equivalence thesis: one is justified in believing iff one has KL-justification.
So, first, those to consign to the sidelines: those who think an adequate understanding of knowledge does not advert to justification. The bottom line here is an attempt to account for the value or significance or importance of knowledge, and the account I want to question can’t get off the ground without the equivalence thesis. Once rid of these scoffers, here’s what I think one should say:
The justification involved in the nature of knowledge is a functional concept. To wit, that which when ungettiered and combined with true belief, yields knowledge. The idea of justification for belief is an analogical notion, related to justification for action. In each case, we specify a goal, and then justification is that which is related in an appropriate way to the goal. No matter what counts as appropriate here: it will survive the analogy.
Based on these data, we can say this. The primitive notion is justification. The derived notion is a functional one, claiming that KL-justification is, precisely, justification.
F/M think the explanation goes the other way, but the only argument I see (in chapter 6, they say they argued this in chapter 5) is this remark in chapter five: it is plausible to think that KL-justification is explanatorily prior.
This matters, because if justification is explanatorily prior, we don’t have an explanation of the importance of knowledge. If, however, KL-justification is prior, we do. In my dissatisfying role as iconoclast regarding explanations of the value of knowledge, I can’t see why we should favor a plausibility claim over the above account.