“The alien is that which stems from elsewhere and does not belong here . . . The stranger who does not know the ways of the foreign land wanders about lost; if he learns its ways too well, he forgets that he is a stranger and gets lost in a different sense by succumbing to the lure of the alien world and becoming estranged to his own origin . . . The recollection of his own alienness, the recognition of his place of exile for what it is, is the first step back; the awakened homesickness is the beginning of the return.”