Sentence:  Perhaps I was too fond of him at one time—perhaps too fond still—to be entirely fair to his work—Perhaps “oversaw” it formerly—when he potentially lived in me—& “<WSD>undersee</WSD>” it now when I am impatient with all tricks [...] 
Meaning of the word marked with <WSD> tags:  To neglect; fail to see properly or adequately; turn a blind eye to; ignore.