Mediated beliefs raise the question of whether the strategy we adopt is one to which we have a right-one we do well to use. Unmediated beliefs are those which we adopt without moving to them from other beliefs we already have. These raise different problems, which concern the source of our right to believe. I open my eyes and, because of what I see, immediately believe that there is a book in front of me. This focus on justification is one way of expressing the idea that epistemology is normative.
Various answers suggest themselves.
A third is the classic foundationalist claim that this belief is not in fact unmediated, but inferred from a belief about how things seem to me just now. If this last were true, we are thrown back to two questions. The first is whether, and how, the belief about how things seem to me just now is justified. The second is whether the inference from that belief is justified. We might ask what principle of inference is employed.