[onetwo_threefour]

This argument from authority discussion (whether it's a fallacy or not), is interesting as it mirrors the epistemological disagreement between coherentists and foundationalists.

On the one hand we have an assumption that a legitimate consensus among 'experts' would justify belief or appeal to the statements of those experts in their area of expertise. On the other hand you have a stricter evidence based approach saying all appeals to consensus are fallacious.

Both are problematic, the first assumes that we can assess the legitimacy of a consensus. However, that just removes the question back a step. That is to say that we are not appealing directly to authority anymore, as you have to drive down into what makes a consensus legitimate, or to be circular, what makes it authoritative.

On the other hand demanding complete evidence for every claim just isn't feasible in the real world and knowledge could never spread if no one could rely on naything said without a complete discussion from first principles.