Sight, and its object light, appear to be universal metaphors in human language, both for intellectual apprehension or activity and its objects and also for the experience of aesthetic and moral values. The figure is applied equally to the course or end of a rational approach to knowledge, giving scarcely-felt imagery like ‘I see’, ‘look into’, etc., or to a pictorially described ‘illumination’ or ‘vision’ that lies beyond the range of reason. Some phrases are applicable in both senses; to ‘see the light’ may connote either logical grasp of a fact or religious conversion.