In The Work of Art in the Age of Mechanical Reproduction, Benjamin defines aura as a work of art's "uniqueness" (223). He further explains that aura, or "the unique value of the 'authentic' work of art, has its basis in ritual, the location of its original use value" (224). At this point, the value of authenticity in a work of art is apparent, since Benjamin argues that when authenticity is lost, the function of art changes from ritual to political (224). According to Benjamin, the authenticity and authority of a work of art is jeopardized as it becomes mechanically reproduced and achieves a greater exhibition value, rather than a ritual value (226).
Chris Long on 08 Sep 10Ritual value versus use value can be addressed here. See, the discussion of cult value, note 5, p. 243.