Analysis of Promise Of Peace

The heads of strong old age are beautiful
Beyond all grace of youth. They have strange quiet,
Integrity, health, soundness, to the full
They've dealt with life and been tempered by it.
A young man must not sleep; his years are war,
Civil and foreign but the former's worse;
But the old can breathe in safety now that they are
Forgetting what youth meant, the being perverse,
Running the fool's gauntlet and being cut
By the whips of the five senses. As for me,
If I should wish to live long it were but
To trade those fevers for tranquillity,
Thinking though that's entire and sweet in the grave
How shall the dead taste the deep treasure they have?