Reading this poem brings with it many emotions. The strongest I found was a sense of melancholy, sadness and loneliness, which in turn is the theme I found most obvious. With these emotions came a sense of beauty. Lines 13-14 of the poem read "With tremulous cadence slow, and bring The eternal note of sadness in". It seems like Arnold is finding a reflection between the Sea, and the sadness he feels in the world. The rhythm of the tides and the calmness and tranquility of the water bring an escape, but at the same time a reminder to the sadness that is his reality. .
On line 9 of the poem, Arnold writes "Listen! you hear the grating roar". This is a comparison to the "mournful roar" Sophocles spoke of in Antigone. He may feel as though he now understands that what he sees and feels about the world is not just him. A sense of loneliness is lifted in the second verse, maybe as Arnold realizes he's not the only one who sees what has gone wrong in the world. .
Lines 21-22 of the poem read "The sea of faith Was once, too, at the full, and round earth's northern sea". This makes it sound as though Athur is at the point of questioning his religious faith. At the same time, he seems to regard religious faith as something that has been lost. By himself or by society, I am not sure.
The last verse of the poem seems to contain some threat or foreshadowing of pain and struggle to come throughout the world. Line 32 reads "So various, so beautiful, so new", referring to the world before him, but line 34 reads "Nor certitude, nor peace, nor love, nor light". This creates a paradox, between right and wrong, or good vs. Evil. Perhaps Arnold uses these phrases not only referring to the world, but also to himself. This can be explained further in the final line of the poem, "Where ignorant armies clash by night". This draws reference from the Pelopenesian War, where the battle fought in darkness caused the armies to kill their enemies, but at the same time their friends, or more simply themselves.
