Intellectual superiority is not always accompanied by an equal degree of moral superiority, and the greatest geniuses may have much to expiate. For this reason, they often have to undergo an existence inferior to the one they have previously accomplished, which is a cause of suffering for them the hindrances to the manifestation of his faculties thus imposed upon a spirit being like chains that fetter the movements of a vigorous man. The idiot may be said to be lame in the brain, as the halt is lame in the legs, and the blind, in the eyes.
Allan Kardec