Does the general theme of there being “only one everything” violate some fundamental piece of set theory, the Axiom of Comprehension or something? Did John and John get it wrong?
Since they are using “one” in a purely metaphorical sense, I’d say they could make it mean whatever they wanted. No math is involved.
Yeah, poetic license aside obviously–why even bother talking about meaning or truth in cases where such are meaningless? (Though I’m not so sure that’s the case here anyway; the lyrics seem to be an assertion, not just poetics. But I don’t care to argue that point here.)
Also, I think I mean assume, not violate, the Axiom of Comprehension in the OP.