Dashes, Capitals, and a Will of Her Own
Yes, yes… Dickinson uses a bunch of dashes in this poem, just like she does in every poem. It's her thing, and it definitely comes in handy when she wants to emphasize something. The third line is a good example:
Much Sense—the starkest Madness— (3)
See how the dashes set apart the second half of the line, making us pay extra attention to the stark madness? Of course, you do. Actually, the most interesting dash-moment in this poem is in line 4. What's interesting about it? Well, there's no dash at all:
Much Sense—the starkest Madness—
'Tis the Majority
In this, as all, prevail— (3-5)
By skipping on the dash in this one line, Dickinson allows it to spill directly over into the next—a poetic device called enjambment. It speeds up the rhythm of the poem and seems to boost the speaker's frustration with that all-prevailing Majority.
Dickinson also uses another of her favorite tricks: capitalizing words for emphasis. Usually, she does this with words that touch on the major themes. Here, we've got "Madness," "Sense," and "Majority" (1-4). We figure it's Dickinson's way of saying, "Look, people. This is what this about." The capitalization can also make the words bigger. When we see a capitalized "Eye" and "Chain," we know we're not just talking about any random eyeball or chain. We're going big and metaphorical. We're talking about insight and oppression.
Beyond all the usual Dickinson calling cards that we find here, we also find some of her pet themes. We've got her obsession with the human mind, which makes a lot of sense for a lady who spent most days locked up in her own thoughts. (Check out "The Brain—is wider than the Sky—" for another example.) We've also got a touch of her God obsession when she claims that insanity is divine. More than anything else, we get a heaping helping of her characteristic snark here. The poem is kind of sarcastic and biting in its attack on the "sane Majority." Nobody would ever call Dickinson a laugh riot, but we're pretty sure she wrote this one with a smirk on her face.