Any use of commas in a list for something other than separating items, regardless of Oxford comma, makes for ambiguous sentences. That one is just written to make the Oxford comma a culprit. Try:

    To my mother, Ayn Rand, Jimmy, Bobbie and Sue.

> Any use of commas in a list for something other than separating items, regardless of Oxford comma, makes for ambiguous sentences.

I've always felt that the use of parentheses for grouping is under-explored:

    To ((my mother (Ayn Rand)) and God).

Of course, this conflicts with the well ingrained tendency to subconsciously delete parentheticals, but, while pipe-dreaming, one could imagine different marks:

    To {{my mother {Ayn Rand}} and God}.

I'm actually serious about my belief that this sort of thing is logically sensible, but recognise its practical drawbacks ((a) everyone likes the visual appearance of Lisp, right? and (b) everyone speaks Esperanto or Lojban because of its logical primacy, right?).

Not so. There, you unambiguously have a list. If you have a list with a comma in an item, you separate list items with semicolons. So if Ayn Rand was the mother, then it would be "To my mother, Ayn Rand; Jimmy; Bobbie and Sue." The original is difficult because, if "Ayn Rand" is actually subordinated and not a list item, then you don't have a place to put a list separator at all.

Well, an argument in favour of the Oxford comma in that sentence is that Ayn Rand didn't have any children, as anyone who would care for the name would know, so it's clearly a list of three items. :)

For clarity in this case, you would distribute the "to" if the writer's mother is indeed Ayn Rand:

  To my mother, Ayn Rand, and to God

and otherwise assume not (or completely distribute the "to" for no ambiguity).

EDIT: My sibling post has another good alternative.

Of course we only need to add to in writing. When speaking this we'd pause before and after "Ayn Rand", which we'd say in a lower hohum-style intonation.

"To my mother, Ayn Rand and God"

Remove the comma and their mother is both Ayn Rand and God. That's a really terrible example since the Oxford Comma actually works slightly better than the alternative since the problem there is the ambiguity created by the ordering, not the punctuation.

Because that conclusion would be nonsensical, that leaves the alternative that "Ayn Rand and God" are an entirely separate part of the sentence. At least for me, removing the Oxford comma made it much clearer that Ayn Rand was not the mother when reading the sentence. You're mileage may vary, but using nonsense interpretations seems odd for a sentence that is not meant to be read by a computer.

It's odd that you're imagining that the concluding that the person's mother is Ayn Rand and they are dedicating a book to God is a sensible reading. Having known some Randoids the non-Oxford form's interpretation actually seems more plausible to me, but the sentence is nonsensical whatever punctuation you use and neither form seems any less nonsensical to me.

If that's the best case they have against the Oxford comma it seems to be an exception that proves the rule.

The writer chose to construct that list in a confusing & ambiguous way.

You could say "To Ayn Rand, God, and my mother" and lose the ambiguity.

  To my mother Ayn Rand, and to God

Not the same wording, but that's how I would write it, given the freedom.