Full Idea
The concept of justification is absolutely central to epistemology; but this concept is normative (i.e. it lays down norms), so epistemology can't be reduced to factual cognitive psychology.
Gist of Idea
Justification is normative, so it can't be reduced to cognitive psychology
Source
Bernecker / Dretske (Knowledge:Readings in Cont.Epist [2000], Pt.III Int)
Book Reference
'Knowledge: readings in contemp epistemology', ed/tr. Bernecker/Dretske [OUP 2000], p.232
A Reaction
A simple rejection of the 'epistemology naturalised' idea. Best to start with slugs rather than people. You can confuse a slug, so it has truth or falsehood, but what is slug normativity? This is an interesting discussion point, not an argument.