Zeitgeist: Time to discard the Christian story? from CPX on Vimeo.
Although I think this is a good refutation by Dr. Forbes, I have a couple of clarifying points.
As far as I know, the death story presented by Dr. Forbes is the death story of Osiris, not Horus. Dr. Forbes also describes Horus as "not the sun god," which is partially true. There are actually two gods named Horus in Egyptian mythology that are, over the course of time, fused into one (Horus, the sun-god, and Horus the child of Isis and Osiris). However, the predominant story in the Pyramid Texts, Coffin Texts, and the Book of the Dead is that of Horus, the child of Isis and Osiris. One reason for the confusion is that the same story of Horus, the sun-god, has also been depicted as Horus, the child of Isis and Osiris. The story of the fight of the sun-god, Horus, against darkness has also been acknowledged as the combat between Horus, the son of Osiris, and Osiris' brother, Set, for the right to Osiris' throne. In fact, it is this story in which Horus battles Seth (Set) and fatefully loses his left eye in the battle. This alleged sacrifice of Horus' left eye, when presented before the mummified Osiris, is what brought Osiris back to reign as King of the Dead.
 The Egyptian Book of the Dead, trans. E.A. Wallis Budge, CXX-CXXI
 Joseph Campbell. The Mythic Image. pgs. 29, 450
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