Editor! Editor!

My father remains my best line-editor. Others--my husband, my writing group, my colleagues around the world--are wonderful for helping me with the big ideas, the implications of theory, the allusions and notions that I've missed or wrongly emphasized, but for elegant styling, my father remains the best.

So, when I sent him a copy of my paper on Kim Philby's memoir, I was not surprised to receive, in response, a brief nod of praise followed by five or six instances where he noted an inconsistency, a moment of confusion. This one, in particular, however, continues to amaze me. My paper has a long meditation on the ironies of Kim Philby taking his name from the Kipling novel, Kim. My father thought it might be worth a footnote to add:
Of course, the fictional Kim spies for crown and Empire, while Philby successfully did the reverse.
When I went to add that lovely small observation in my paper, I grew self-conscious about lifting his language entire, so I momentarily put:
Of course, the fictional Kim spies for crown and Empire, while Philby worked against it.
Not nearly as good, is it? My flat-footed pairing of for vs. against lacks the elegance of "did the reverse."

I can't quite figure out why his is so much better. Can you?

Needless to say, his phrasing now stands.