My sister and I, you will recollect, were twins, and you know how subtle are the links which bind two souls which are so closely allied.
Arthur Conan DoyleYet birth, and lust, and illness, and death are changeless things, and when one of these harsh facts springs out upon a man at some sudden turn of the path of life, it dashes off for the moment his mask of civilization and gives a glimpse of the stranger and stronger face below.
Arthur Conan Doyle