Robert Browning, a cherished poet of the Victorian era, has many of his poems filled with unbridled optimism. By the term “Optimism”, one means positive attitude or thought process. If you are optimistic, you will tend to see the good or positive in everything that happens, even if it initially appears downright challenging and negative.
When Browning was writing, the attitude of the milieu was scientific and materialistic. And this means, people had lost faith in religion, morality and spirituality. But that was where Browning differed from his contemporaries. He was optimistic about the existence of God and the notion of a perfect heaven. His poetry is a reflection of this, deviating from the scientific temperament typical of his age.
Let's consider the religious fervor in the following lines taken from his poem Song from Pippa Passes,
God's in His heaven—
All's right with the world!
Also, in his poem Rabbi Ben Ezra, he writes...
Grow old along with me!
The best is yet to be
And there can be many such examples. I would not refrain here from mentioning that whether Browning’s poetry can be fully called as optimistic remains a topic for debate. Any work of literature, especially poetry, is subjected to the subjective interpretation of the readers.