 One might compare the expansion of informal logic to account for visual arguments to the attempt to expand the language of formal logic (and, some argue, the notion of argument it embraces) to allow visual deductions (see Barwise and Etchemendy 1998). Visual premises can be used in geometric proofs, in legal arguments (to proving that someone committed a crime, that the murder was heinous, etc.), in reasoning about planets, stars and black holes, and in aesthetic criticism and evaluation. In ornithology, a well authenticated, clear photograph of a rare species (say, the Ivory Billed Woodpecker) is widely accepted as the proper proof that the species is not extinct. 