Sentence:  In the old days, to my commonplace and unobserving mind, he gave no evidences of genius whatsoever. He never read me any of his manuscripts, [...], and therefore my lack of detection of his promise may in some degree be pardoned. But he had then none of the oddities and mannerisms which I <WSD>hold</WSD> to be inseparable from genius, and which struck my attention in after days when I came in contact with the Celebrity. 
Meaning of the word marked with <WSD> tags:  To maintain, to consider, to opine.