"A man saw not his fellow, neither rose any from his place for three days" (the Plague of Darkness, Exodus 10:23). Indeed, there is no greater darkness than one in which "a man saw not his fellow" -- in which a person becomes oblivious to the needs of his fellow man. When that happens, a person becomes stymied in his personal development as well -- "neither rose any from his place." -- Chassidic master Rabbi Yitzchak Meir of Ger (1789-1866)