The timidity of the child or the savage is entirely reasonable; they are alarmed at this world, because this world is a very alarming place. They dislike being alone because it is verily and indeed an awful idea to be alone. Barbarians fear the unknown for the same reason that Agnostics worship it - because it is a fact.
Poets do not go mad; but chess-players do. Mathematicians go mad, and cashiers; but creative artists very seldom. I am not, as will be seen, in any sense attacking logic: I only say that this danger does lie in logic, not in imagination.