Imagination can overcome reason when for example a person is paranoid about someone or something and conjures up possible fearful situations or scenarios that could result from being in that situation or with such and such people when in fact the actual living of that situation is usually far less fearful than imagined but it can immobilize a person if he/she succumbs to their imagination.
I would say it's the Historian because they study history or the past and have to interpret it so they can figure out how to teach it or stop it from happening again.
