How does Tennyson bring mental pessimism and Victorian optimism in his use of myths and legends?

"And we are here as on a darkling plain
Swept with confused alarms of struggle and flight,
Where ignorant armies clash by night."
[Dover Beach: Mathew Arnold]
"The year is at the spring
And day is at the morn, …
God's in heaven,
All is right with world."
[Pippa Passes: Robert Browning]
These above quoted two quotations are from two renowned poets of Victorian arena show the contrast attitudes to their time. Browning is very optimistic of everything because he does not have any mental torment of his age. On the contrary Mathew Arnold is very critical of his age, which he has fou…