Can you help me with the meaning of this poem? and is the first line a paradox and if so, why is it?

I think Emily inson is referring to the person who is content with their own self/or she could be referring to the solitude of the soul that occurs after death or what she is hoping death would be. Please remember that Emily lead a very solitary life before she married and perhaps she grew to love her solitude although I don't think she really had much choice.