[155] To which, then, of the passions which affect the body shall we compare that passion in the soul which is called ignorance? To the deprivation of the organs of the external senses? Therefore all those, who have been injured in their eyes or ears, are no longer able to see or hear at all, but have no acquaintance with day or light, which are the only objects for the sake of which, if we are to tell the plain truth, life is really desirable, but dwell in lasting darkness and everlasting night, being made insensible to everything whether of small or great importance; men whom ordinary conversation naturally is accustomed to call infirm.