Dickinson was a linguistic genius. All she had to hear was one word to get her going. It's a matter of reading technically specialized, difficult language. Of meticulously analyzing, element by element. She compresses a lot of ideas.
Every symbol counts.
By adding a last word, she can change the meaning of a sentence. . . The essay went through 13 drafts, and cites dozens of literary sources. Nor will this be his only piece of Dickinson scholarship. There is treasure here.