What is the theme of "Dover Beach" by Matthew Arnold?
Central to understanding this poem is recognising that through it Arnold is lamenting the loss of faith or culture in his society and painting a picture of a world that, as a result of this loss of faith, is full of cruelty, uncertainty and violence.
Note how the sea imagery develops this theme. Reference to the "Sea of Faith" and its gradual withdrawal from the coast indicates that Arnold considers its loss is a negative occurrence:
The Sea of Faith
Was once, too, at the full, and round earth's shore
Lay like the folds of a bright girdle furled.
But now I only hear
Its melancholy, long, withdrawing roar...
Note how the sound the Sea of Faith makes as it withdraws is described as "melancholy" and that as it leaves it exposes the "naked shingles of the world," leaving the world exposed, vulnerable and open to wounding.
The final stanza describes Arnold's view of this new world that is marked by its absence of Faith. This world, although it may appear to be "like a land of dreams," actually is not. Instead it:
Hath really neither joy, nor love, nor light,
Nor certitude, nor peace, nor help for pain...
As a result, Arnold imagines that he and his beloved are on a "darkling plain" only listening to the sounds of "ignorant armies" clashing by night. In such a world, love is the only consolation that can be found, and therefore, the speaker urges his lover and himself to "be true to one another."