Arnold's best-known poem is probably "Dover Beach," which begins: "The sea is calm to-night./The tide is full, the moon lies fair/Upon the straits." The poem then proceeds onward to the "melancholy, long, withdrawing roar" of "the Sea of Faith," before ending on the famous "darkling plain . . . Where ignorant armies clash by night."
But the sea is present in a number of other poems of his as well, including the following poem addressed to "Marguerite." Arnold first met "Marguerite" in September of 1848 on a sojourn in Switzerland, saw her again when he returned a year later, and then parted from her for ever. Her identity is unknown (despite the detective work of scholars). Some argue that she was an invention. I prefer to think not.
Yes! in the sea of life enisled,
With echoing straits between us thrown,
Dotting the shoreless watery wild,
We mortal millions live alone.
The islands feel the enclasping flow,
And then their endless bounds they know.
But when the moon their hollows lights,
And they are swept by balms of spring,
And in their glens, on starry nights,
The nightingales divinely sing;
And lovely notes, from shore to shore,
Across the sounds and channels pour --
Oh! then a longing like despair
Is to their farthest caverns sent;
For surely once, they feel, we were
Parts of a single continent!
Now round us spreads the watery plain --
Oh might our marges meet again!
Who ordered, that their longing's fire
Should be, as soon as kindled, cooled?
Who renders vain their deep desire? --
A God, a God their severance ruled!
And bade betwixt their shores to be
The unplumbed, salt, estranging sea.
Matthew Arnold, Empedocles on Etna, and Other Poems (1852).
If one were being less than charitable to Arnold, one could argue that the poem is Arnold's after-the-fact philosophical/ontological/theological rationalization for failing to pursue the love of his life. I can see the point. Sort of.
But then there is line 4: "We mortal millions live alone." Call me sappy and sentimental, but those italics speak volumes.
Well, what does one do with a life-long regret?