“If I read a book [and] it makes my whole body so cold no fire can ever warm me, I know that is poetry. If I feel physically as if the top of my head were taken off, I know that is poetry. These are the only ways I know it. Is there any other way?”

 Emily Dickinson, Letter to Thomas Wentworth Higginson, 16 August 1870

Also:

Poems on Fragments of Paper | Emily Dickinson, 1830- 86

Letter to Mary Haven | Emily Dickinson, 1859