Which universal theme does this poem build on?

Brave, brave were the soldiers (high named to-day) who lived through the fight;
But the bravest press'd to the front and fell, unnamed, unknown.
(from "The Bravest Soldiers" by Walt Whitman)

Question

Which universal theme does this poem build on?

    Brave, brave were the soldiers (high named to-day) who lived through the fight;
    But the bravest press'd to the front and fell, unnamed, unknown.
    (from "The Bravest Soldiers" by Walt Whitman)

anonymous · Answer

Were there options? I would go for something like Heroism

anonymous · Answer

heroism

death and rebirth

salvation

love and duty