One night, the speaker of "Dover Beach" sits with a woman inside a house, looking out over the English Channel near the town of Dover. They see the lights on the coast of France just twenty miles away, and the sea is quiet and calm.
When the light over in France suddenly extinguishes, the speaker focuses on the English side, which remains tranquil. He trades visual imagery for aural imagery, describing the "grating roar" of the pebbles being pulled out by the waves. He finishes the first stanza by calling the music of the world an "eternal note of sadness."
The next stanza flashes back to ancient Greece, where Sophocles heard this same sound on the Aegean Sea, and was inspired by it to write his plays about human misery.
Stanza three introduces the poem's main metaphor, with: "The Sea of Faith/Was once, too, at the full, and round earth's shore." The phrase suggests that faith is fading from society like the tide is from the shore. The speaker laments this decline of faith through melancholy diction.
In the final stanza, the speaker directly addresses his beloved who sits next to him, asking that they always be true to one another and to the world that is laid out before them. He warns, however, that the world's beauty is only an illusion, since it is in fact a battlefield full of people fighting in absolute darkness.
Arguably Matthew Arnold's most famous poem, "Dover Beach" manages to comment on his most recurring themes despite its relatively short length. Its message - like that of many of his other poems - is that the world's mystery has declined in the face of modernity. However, that decline is here painted as particularly uncertain, dark, and volatile.
What also makes the poem particularly powerful is that his romantic streak has almost no tinge of the religious. Instead, he speaks of the "Sea of Faith" without linking it to any deity or heaven. This "faith" has a definite humanist tinge - it seems to have once guided decisions and smoothed over the world's problems, tying everyone together in a meaningful way. It is no accident that the sight inspiring such reflection is that of untouched nature, almost entirely absent from any human involvement. In fact, the speaker's true reflection begins once the only sign of life - the light over in France - extinguishes. What Arnold is expressing is an innate quality, a natural drive towards beauty.
He explores this contradiction through what is possibly the poem's most famous stanza, that which compares his experience to that of Sophocles. The comparison could be trite, if the point were merely that someone long before had appreciated the same type of beauty that he does. However, it is poignant because it reveals a darker potential in the beautiful. What natural beauty reminds us of is human misery. Because we can recognize the beauty in nature, but can never quite transcend our limited natures to reach it, we might be drawn to lament as well as celebrate it. The two responses are not mutually exclusive. This contradictory feeling is explored in many of Arnold's poems - "The Scholar-Gipsy" and "A Dream" are two examples - and he shows in other poems an instinct towards the tragic, the human inability to transcend our weakness (an example would be "Consolation," which presents time as a tragic force). Thus, the allusion to Socrates, a Greek playwright celebrated for his tragedies, is particularly apt.
Such a dual experience - between celebration of and lament for humanity - is particularly possible for Arnold, since mankind has traded faith for science following the publication of On the Origin of Species and the rise of Darwinism. Ironically, the tumult of nature - out on the ocean - is nothing compared to the tumult of this new way of life. It is this latter tumult that frightens the speaker, that has him beg his lover to stay true to him. He worries that the chaos of the modern world will be too great, and that she will be shocked to discover that even in the presence of great beauty like that outside their window, mankind is gearing up for destruction. Behind even the appearance of faith is the new order, and he hopes that they might use this moment to keep them together despite such uncertainty.
The poem epitomizes a certain type of poetic experience, in which the poet focuses on a single moment in order to discover profound depths. Here, the moment is the visceral serenity the speaker feels in studying the landscape, and the contradictory fear that that serenity then leads him to feel. To accomplish that end, the poem uses a lot of imagery and sensory information. It begins with mostly visual depictions, describing the calm sea, the fair moon, and the lights in France across the Channel. "The cliffs of England stand/Glimmering and vast" not only describes the scene, but establishes how small the two humans detailed in the poem are in the face of nature.
Perhaps most interestingly, the first stanza switches from visual to auditory descriptions, including "the grating roar" and "tremulous cadence slow." The evocation of several senses fills out the experience more, and creates the sense of an overwhelming and all-encompassing moment.
The poem also employs a lot of enjambment (the poetic technique of leaving a sentence unfinished on one line, to continue and finish it on the next). The effect is to give the poem a faster pace: the information hits us in rapid succession, forming a clear picture in our minds little by little. It also suggests that Arnold does not wish to create a pretty picture meant for reflection. Instead, the beautiful sight is significant because of the fear and anxiety it inspires in the speaker. Because the poem so wonderfully straddles the line between poetic reflection and desperate uncertainty, it has remained a well-loved piece throughout the centuries.