
Originally Posted by
Pantz
Show me an example to the contrary (where the use or non-use of the serial comma is optimally chosen, of course)!
Your very first sentence was this:
I took my father, a potato and Michael to see the strippers, JFK, and Stalin.
Now follow it with this:
"Then my brothers, John and David, went to the mall."
This is a classic if-there's-no-serial-comma-it's-ambiguous sentence (you can replace it with a classic if-there-is-a-serial-comma-it's-ambiguous sentence, and reverse the positions of everything in the following two paragraphs; I can't be arsed to write it all out twice).
In your sentence, you didn't use the serial comma in the first trio because they were obviously three separate items either way, but you did in the second trio to "eliminate the ambiguity". But let's say John and David really are your brothers. Because you were inconsistent in the previous sentence, the reader doesn't know that anymore.
Had you been consistent in your first sentence, and used the serial comma in both cases, its absence here would have made your meaning in the second sentence clear.