5. a group of people sharing an interest, activity, upbringing, etc; set: golf circles ; a family circle
“There may be such circles, but their existence is something about which I am unaware.”
I am sure the circles are animate. When referring to them they should be recognized as such. I also think, if I may be so bold, that the word “of” is a preposition and intelligent people generally concede they should avoid ending sentences in prepositions, which you made no mention of. Heh heh heh.
I'm pretty sure the circles are figurative.
I wouldn't mention the practice of ending a sentence with a preposition, since it seems to be a fairly common grammatical construction in English. If this exchange were taking place in French, I might comment, since ending sentences with prepositions would sound utterly bizarre in French. The Oxford dictionary people have this to say: There’s no necessity to ban prepositions from the end of sentences. Ending a sentence with a preposition is a perfectly natural part of the structure of modern English.