Much Madness Is Divinest Sense

The people treated as insane in "Much Madness is divinest Sense---" are those who 

• value thoughtfulness
• speak opposing viewpoints
• assent to the majority
• have a discerning eye

Dickinson most likely uses dashes in "Much Madness is divinest Sense---" to

• build lines of equal length
• alter the sounds of the poem
• draw attention to capitalization
• highlight the conflicting ideas

According to "Much Madness is divinest Sense--" people would be "handled with a Chain" for

• seeing things clearly
• being part of a majority
• thinking for themselves 
• being a danger to themselves 

The poet most likely capitalized Majority and All  in "Much Madness is divinest Sense---" to emphasize the

• total power of the majority 
• gap between sanity and madness
• size of a city's population
• foolishness of the minority 

Verse 6 and 7 contain the main opposing ideas. These are...

• Always demur, never assent

• Always assent, never demur

• Pretend you are mad, never sane

• If you agree with the majority you are safe. If you disagree, you are insane