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- The "Sea of Faith" represents the "ocean" of religious belief in the world—all of our faith put together. Notice that Arnold capitalizes this term and puts it all by itself at the top of the stanza, so we're sure to notice that it's super-important.
- There was a time, the speaker says, when that "Sea of Faith" was at high tide "full" just like the English Channel is right now.
- He's really driving this whole ocean-as-metaphor thing hard.
- But what's he referring to? Perhaps an earlier time, when religion was more important in people's lives?
Throughout the poem, the sea is used as an image and a metaphor. At first, it is beautiful to look at in the moonlight (ll.1-8), then it begins to make hostile sounds ("grating roar" (l. 9); "tremulous cadence" (l.13)) that evoke a general feeling of sadness. In the third stanza, the sea is turned into a metaphoric "Sea of Faith" (l.21) — a symbol for a time when religion could still be experienced without the doubts brought about by progress and science (Darwinism). Now, the 'Sea of Faith' and thus the certainty of religion withdraws itself from the human grasp and leaves only darkness behind.
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