Read the following passage from Book VII of Gilgamesh:
"Enkidu said, '...Beloved brother, last night I had a second bad dream....I tried to struggle, but with one blow [an eagle] capsized me like a raft, he leaped upon me, like a bull he trampled my bones. 'Gilgamesh, save me, save me!' I cried. But you didn't save me. You were afraid and you didn't come. The creature touched me and suddenly feathers covered my arms, he bound them behind me and forced me down to the underworld, the house of darkness, the home of the dead, where all who enter never return to the sweet earth again'" (Mitchell 142-143).
Based on this passage, Enkidu’s thoughts and dreams about the underworld illustrate that the Mesopotamians viewed death as