This poem hit me very deeply: the mix of overbearing desperation, purposelessness, and ennui with a profound longing for something more, some tentative hope or answer on the horizon -- all encapsulated in a poem that offers no true resolution but rather rests on a sense of anxiety and skepticism, an equivocation between optimism and pessimism that lacks any sheer conviction. For example, Hardy only "could think" there "trembled" through the thrush's air some hope, but he is far from sure, although it is as if he wants to be. This seems to me to be a very religious and existential poem, where the thrush represents a sense of hope and faith in the ways of the world, in imparting meaning on "terrestrial things," whereas Hardy is more skeptical of any type of faith that will bring him above his gloom. He seems to mourn for the fact that he is not privy to the almost juvenile joy of the thrush, like an atheist who is always unconsciously mourning for some lost god. Either way, Hardy seems to be a forbear of a modernist kind of skepticism and vacillation between hope in progress and desperation in the face of disaster, with no clear answers to be found.