"A savant thawed." This illustration from Jules Verne's The Fur Country
(1874) reminds us of a concept from Theosophy, that an enlightened fraternity secretly preserves the ancient universal wisdom through humanity's dark ages. Or, as explained in Annie Besant's The Masters
At certain times in human history, in serious crises, in the transitions from one type of civilization to another, members of the Occult Hierarchy, Masters and even loftier Beings, come out into the world; normally although incarnate, they remain in retired and secluded spots, away from the tumult of human life, in order to carry on the helpful work which would be impossible of accomplishment in the crowded haunts of men.
Indeed, that's what "a savant thawed" reminded us of.