This poem states that what is often declared madness is actually the most profound kind of sanity (“Much Madness is divinest Sense –“), when viewed by someone with “a discerning Eye.” What is often called sense or sanity is in fact not just “Madness,” but profound madness (“the starkest Madness”). It is only called “Sense” because it is not defined by reason, but by what the majority thinks (“’Tis the Majority / In this, as All, prevail –“).
Since the majority rules, the act of agreeing, no matter to what, means that you are, in the public mind, sane (“Assent – and you are sane –“). If you disagree, or even hesitate in your assent, you are not only declared crazy, but dangerously so (“Demur – you’re straightway dangerous –“). The act of disagreeing with the majority leads to a loss of freedom (“And handled with a Chain –“), thus one can either be physically free, but ruled by the majority, or imprisoned with their own beliefs.
“Much Madness is divinest Sense –“ is a difficult poem to read without thinking of Dickinson’s biography. The poem can certainly be read and understood without reference to her life, as the message itself is, while powerful, fairly simple to understand—what is called madness is often actually the truest sanity, but as long as it differs from the perspective of the majority who defines what is right and wrong, it will be called madness.
Knowledge of Dickinson’s life, however, can add layers to the poem, especially as she was often called mad, both in her lifetime and after her death. This poem, then, can be seen as a defense of her reclusion from society. Dickinson had participated in a fairly full social life into her twenties; her seclusion was a conscious choice to remove herself from this, and so she fully knew what she was missing out on, and could thus judge it—what society defined as “Sense”—in her poetry.
Thus although many have presented this reclusion as a symptom of her insanity, it was actually just a decision not to live the way the majority did, just because the majority said it was the way that she should live. In her seclusion, she wrote incredibly prolifically, freed from the constraints of societal responsibilities. She chose her art over society, and while she may not claim this was “divinest Sense,” it was certainly not an insane choice just because it was different, and many more have profited from it, in reading her poetry, than would have profited from her presence in society in her lifetime.
This poem is not just concerned with the judgments of “Madness” or “Sense,” however, but with the prospect of any judgments that have important ramifications, and with who has the power to make them. In this poem, the judgment of a person’s insanity is made “straightway,” and only because this person chooses to “Demur” from the majority. The diction here, especially in the contrast between the extremes of these two words—“straightway” is as fast as a decision can be made, while “Demur” is a rather weak form of objection, as opposed to, say, a rebellion.
There is no slow, steady, rational process of judgment before this person is labeled insane and “handled with a Chain,” it is instead simply a kneejerk reaction, yet one that takes away the “insane” person’s freedom. The use of the word “Chain,” too, has a hint of violence to it, so it is not just a loss of freedom, but potentially a violent one. Dickinson is, throughout her poems, very concerned with the issue of truth, and the fact that it is almost impossible to ever really find it. If this is the case, then passing judgment in any fair way is inherently impossible, and to do so quickly is a horrifying crime.