In "The Darkling Thrush," does the bird know of a hope unknown to the speaker? Does the speaker think it does?
This poem can be looked at as an optimistic poem. The opening stanza depicts a desolate and cold world that we live in. Hardy uses words like "corpse" and "crypt" to compare to the setting. During the time this poem was written (first day of the new century), Harding was saddened to see the the Industrial Revolution take over what was once run by a rural society. That explains his setting a little more.
Then the thrush begins its singing. This bird is not a young, exotic bird. This bird is just a common, old and frail thrush. So the joyful sounds coming from this bird does offer some sort of hope at the end of the day. The speaker says in the last stanza that he "could think there trembled through his happy good-night air some blessed Hope." The speaker recognizes that the bird offers hope. And coming from just a worn out and diminished bird, makes that hope significant. However, he admits that he is unaware of what that hope is. Harding's capitalization of the word "Hope" also tells us that the hope is significant.
The bird can represent that even the weak and the frail can generate some kind of hope in desparate times.