Much Madness is divinest Sense- Alienation Unit

Much Madness is divinest Sense by Emily Dickinson is a poem of paradoxical proposition. Insanity is good sense and good sense is insane. "To a discerning Eye..." [Dickinson, 830] refers to a person who takes notice in things and in this poem it is referring to a person who notices that insanity is good sense. I have trouble figuring out why the words "discerning" and "Majority" provide the resolution of the paradox. I believe it is because those words bring about an uncertainty. They make us rethink insanity and good sense so that they no longer coincide. I have to be completely honest and say that I am having trouble comprehending this poem in general. I see the two parts, the insanity and the good sense, but I can not pick out what pulls them apart or what brings them together.