We are ourselves a rich source of expertise regarding many matters. While we don’t always fully appreciate this expertise and often distort or make poor use of this personal expertise, it is there for our use – thanks to our capacity to process at multiples in our brain at the same time, and thanks to the recent expansion in the human brain of an advanced mental processing system (the prefrontal cortex).

Experts are in trouble. And our whole society is in trouble. We don’t know what to believe and our experts often seem to have only a tenuous grasp on reality. These concerns are societal products of late 20th and early 21st Century thought. I would also note that there is a much earlier source: Plato's allegory of the cave.