Men do not know the natural infirmity of their mind: it does nothing but ferret and quest, and keeps incessantly whirling around, building up and becoming entangled in its own work, like silkworms, and is suffocated in it. A mouse in a pitch barrel...thinks it notices from a distance some sort of glimmer of imaginary light and truth; but while running toward it, it is crossed by so many difficulties and obstacles, and diverted by so many new quests, that it strays from the road, bewildered.