Heard this evening on the PBS NewsHour , a reference to David Petraeus sharing classified information with “his mistress qua biographer.” An arresting characterization, one that I doubt I’ll ever hear repeated.
Bryan Garner has an excellent discussion of qua (meaning “in the capacity of; as; in the role of”), a word he characterizes as “often misused” and “little needed.” Garner quotes H. W. Fowler’s Modern English Usage (1926):
The real occasion for the use of qua occurs when a person or thing spoken of can be regarded from more than one point of view or as the holder of various coexistent functions, and a statement about him (or it) is to be limited to him in one of these aspects.That’s it exactly: Petraeus was sharing information with his lover in her role as his biographer. Here, I think, qua works well. Garner’s recommended alternative — as , as in “his mistress as biographer” — would not work nearly as well here.
Of course, not having a mistress and not sharing classified information would work even better.