LYCOS RETRIEVER 
Heracles: So Hermes
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For his sixth task Heracles had to drive away the Stymphalian Birds, fearsome creatures with bronze beaks that terrorised the lake that they had come to inhabit some years previously. Some accounts say that they had razor sharp feathers that could be fired at attackers.
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Does this show that Heracles’ madness is rooted in an extreme and unstable character? Heracles’ violence is a civilising force; he has a justified enmity with Lycus and Eurystheus; his madness consists more in mistaken perception. Compare divine distortions of perception in Eur. Bacchae (Pentheus, Agave), Soph. Ajax.
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Hera saw to that Sthenelus' son Eurystheus was born before Heracles. Eurystheus was born prematurely. Therefore, Eurystheus would be king of Mycenae and Tiryns, Zeus was furious at Hera, but could not revoke his vow.
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