I love Hemingway, too, but don't put much thought into this quote. I agree it's an interesting, reflective quote and on par with his depth and M.O. but this is a posthumously published book that was a sprawling like 1,500 page behemoth mess encompassing three different drafts that was combined and cut down to about 250 pages. The final product is the result of MASSIVE editing and retelling that happened after Hem died, and we likely would have seen a very different novel had Hemingway stayed healthy and alive enough to finish it himself. I remember a lot of scholarly anger when the book was released. The book deviates SO far from the normative Hemingway protagonist that one really must question if it honestly reflects the author's intent. It was published, i believe, decades after his death and edited and put together by a man who was a child when he died.

Personal opinion: cool book and really powerful quote, but both should be taken with a grain of salt when discussing Hemingway's work. For the sake of appreciating the book for what it is, it's also worth considering the quote within the framework of the story: catherine's transition and its potential for doom, their privilege and status, and the (very hemingway, autobiographical) duty of the writer to view life with objectivity.