what views on the intellect or the soul and society are expressed in"Much Madness is divinest sense" and"The Soul selects her own society"

I interpret Dickinson's message in Much Madness to be that thinking too much about trivial matters can make one crazy. Having madness or a little chaos keeps one divine or sane as in, perhaps, don't sweat the small stuff mentality.

In Soul Selects Her Own Society, the speaker claims that one's inner spirit chooses its own acquaintances or companions and ignores everyone else. Dickinson was a recluse so her desire to remain private could have been her motivation for this poem.

Emily Dickinson's understanding of the intellect/soul in these two poems is actually characteristic of a classical conception posited by Plato and others in antiquity. Especially in "The Soul selects her own society," Dickinson implies that the soul can be free of petty interactions with oppressive situations in finite life. This is akin to Plato's idea of the eternality of the soul.